580
T H E J O U R N A L OF I N D U S T R I A L A N D EiVGI,VEERING C H E J I I S T R Y .
[FROMTHE LABORATORY OF PHYSIOWGICAL CHEMISTRY, DEPARTMENT OF ANIMAL HUSBANDRY, UNIVERSITY OF ILLINOIS.]
CHEMISTRY OF FLESH. [EIGHTH PAPER.]' A PRELIMINARY STUDY OF THE EFFECT OF COLD STORAGE UPON BEEF AND POULTRY. (SECOND COMMUNICATION.) R y A. D.
EMMETT AND H . S. GRINDLEY.
Received April 7 , 1909.
I n connection with the previous study upon the influence of cold storage upon uncooked beef and poultry it was thought that it would be of economic and scientific interest to make several cooking experiments upon some of the fresh and refrigerated uncooked samples and thereby to ascertain what influence, if any, the cooked meats might show over the uncooked, as to the changes brought about during cold storage. It could easily be assumed that the process of refrigeration would produce not only chemical b u t also physical changes in the meats which might not be apparent upon simply analyzing the uncooked product but would be brought out more distinctly by analyzing the cooked samples and the resulting broths and drippings. With this object in view, both boiling and roasting experiments were made upon portions of the same samples of the uncooked loin cuts, laboratory numbers 1969 and 1988, which were studied in the preceding' paper. The former cut was held in storage for 6 days and the latter one for 43 days, both a t approximately 33 '-3 j F. The literature pertaining to the influence of cold storage upon both uncooked and cooked flesh was given in our former paper. EXPERIMENTAL.
For this study, upon the comparative losses and chemical changes resulting in the cooking of refrigerated meat, held in cold storage for varying lengths of time, eight cooking experiments were carried out. The same methods of cooking meats as were formerly3 used in this laboratory were followed. The samples were obtained from the finely chopped and well mixed lean portion of the cuts of the uncooked loin. In the first case, where 1 H S . Grindley, J o u r . Amer. Chem. Soc., 26, 1086 (1904). H. S. Grindley and A. D. Emmett, Ibtd., 27, 658 (1905). A. D. Emmett and H . S. Grindley, I b i d . . 28, 25 (1905). P. F. Trowbridge and H. S . Grindley. Ibid., 28, 4 6 9 (1906). H . S. Grindley and H . S. Woods, J o u m . of Bioi. Chem., 2 , 309 (1907). 4 . D. Emmett and H . S. Grindley, Ibid.. 3, 4 9 1 (1907). A . D. Emmett and H. S . Grindley.
THISJ O U R N A L , 1 , 4 1 3 (1909). cit. 3 Grindley, U . S. D e p f . .4gr., 0.E . S.. Bull. 102 (1901). Grindley and Mojonnier, Ibid., 1 4 1 (1904). Grindley and Emmett, I b i d . , 162 2 LOG.
(1 905).
h u g . , 1909
the meat was kept in storage for 6 days, the following cooking experiments were made : Experiment r.-Boiling a t 8 j 0 C. 1000 grams of the chopped meat were taken, properly prepared and then plunged into 2000 cc. of distilled water, the temperature of which was maintained a t 85' C. The time of cooking was 3 hours. This experiment was done in duplicate. The samples were designated Kos. 1966 and 1967. Expeument ,?.-Boiling a t 100' C. 1000 grams of the sample were used. I t was prepared and then placed in 2000 cc. of vigorously boiling water and cooked thus for 3 hours. The evaporated water was replaced from time to time. This test was also done in duplicate, the samples being designated Nos. 1968 and 1 9 7 7 . Experiment 3.-Roasting a t 1 9 j o C. 1000 grams of the finely divided beef were prepared for roasting in the gas oven. The temperature for the first 15 minutes was 2 j 0 O C. and for the remaining time 195' C. The meat was cooked until the inner temperature' reached 60' C. I n this case the total time of roasting was I hour. The sample was given laboratory number 1978. Experzment 4.-Roasting a t 100' C. 1000 grams of the beef loin sample were roasted in the Xladdin oven. The preliminary searing was done in the gas over at a temperature of 250' C. for I j minutes. The meat was then transferred to an Aladdin oven and cooked a t 100' C. until the inner temperature reached 60' C. The time of cooking was I hour and jo minutes. The cooked product was designated as No. 1 9 7 9 . For the second series of four cooking experiments upon the beef loin which was held in cold storage for 43 days, exactly the same tests were carried out in detail. The time required to cook the gas roast until the inner temperature reached 60' C. was I hour, and the Aladdin roast, to the same degree, was 2 hours and 2 0 minutes. I n preparing the above samples for cooking, the weighed portions were made into loaves of a s nearly the same shape and size as possible. The meats for the boiling tests were wrapped with pieces of cheese-cloth. All the samples were prevented from touching the bottom of the cooking vessels and so arranged that the heat and water could penetrate all sides of the loaves. CHEMICAL METHODS USED.
In analyzing the cooked meats, the same chemical methods were followed as in the case of the un1
Sprague and Grindley, U m w r s t t y Studies, 2, 4
BROWNE O N T H E U S E OF T E M P E R A T U R E CORRECTIO,VS.
as that of Table XI, or the diagram, said corrections (for increase in temperature) to be added to sugars polarizing over 80 and to be subtracted from those polarizing below 80. The use of such a system would be unquestionably more accurate for cane products than any method of correction based upon changes in the specific rotation of sucrose alone and in the long run could be regarded as perfectly just. The great objection to its use, as with all other methods, is that it would not give the true correction for many individual samples of sugar, whose composition, especially as regards invert sugar and moisture, is different from the average type. Any method or scheme of analysis which works injustice to no matter how small a pcrcentage of the trade should meet with disfavor as long as there exists a method which will work absolute justice to all. A second remedy for the difficulties of temperature is suggested by that provision of the International Commission upon Uniform Methods of Sugar Analysis, which states that when “ t h e temperature is higher than 2 0 ’ saccharimeters may be adjusted a t 30’ or any other desired temperature providing that the analysis of sugar be made a t the same temperature.” This adjustment of saccharimeters to temperature above 20’ may be made in several ways. It can be accomplished by changing the quartz wedges of the instrument, or by increasing the normal weight of sugar, or by increasing the length of the observation tube or in any other way that will enable the scale of the saccharimeter to indicate IOO when pure sucrose is polarized a t the specified temperature. When only local polarizations and comparisons are involved it may be advantageous to make some such adjustment as the above. But for the broader work of comparison between distant points, as hetween the tropics and northern latitude, polarizations should be performed under one uniform set of standard conditions and the use of different temperatures of standardization is not advisable,l since comparisons are no longer possible upon a large class of low-grade saccharine products. The same difficulty is introduced as in the correction of polarizations by the formula PZo0 = P‘[I +0.0003 ( t - 20)] or by the suckose values of quartz plates. Two saccharimeters, for example one standardized for the rotation ‘
1 The inadvisability of introducing different standards for saccharimeters is fully discussed by Prinsen Geerligs in “De Indische Mercuur,” April 13, 1909. “Temperaluurs-correctie b i j de Polarimetrische Geltnltebepaling van RielJuiker.”
579
of sucrose a t 20’ and one standardized for the rotation of sucrose a t 30°, will give of course identical results for pure sucrose, b u t not for a raw cane-sugar, nor for a cane molasses, nor for a large class of other products. While the change in specific rotation of sucrose has been corrected, the changes in the specific rotation of the levulose and other impurities have not been equalized. Having adjusted a saccharimeter to any desired temperature, this standard temperature must be rigidly adhered to, if identical observations are always to be obtained between different chemists. The solution of the problems of temperature in the polarization of raw sugars and other products resolves itself then into simply this: If we are to make temperature corrections in the polarization of commercial products, we must correct for variations in the specific rotations of all the ingredients therein present. If i t is impossible to do this no temperature corrections a t all should be attempted, but all polarizations should be made as nearly as possible under standard conditions. Custom House laboratories, Arbitration laboratories, and all other laboratories, upon the results of which great interests are involved, should be equipped with cooling and warming apparatus for maintaining a uniform standard temperature throughout the year. The opinion of Judge Townsend of the Circuit Court in the case of the Importers of Sugar vs. the United States-that if the Government desires to secure uniformity and accuracy in the polarizations of sugars, tests should be made a t the temperature a t which the instruments are standardized-has already been quoted. As an expression of absolute justice and of scientific truth that opinion cannot be reversed, although the decision of this Court, as we have seen, was afterwards set aside by the Court of Appeals. The services rendered to science by the researches of the many chemists who have investigated the influence of temperature upon the specific rotation of sucrose are great; the results of their labors are lasting and will stand the test of time. The application, however, of what they have established for pure sucrose to the polarization of all grades of saccharine products is a misapplication. I t is a great mistake. I t will increase rather than diminish the errors between many of the saccharimetric observations of different analysts and is bound to work great injustice when applied commercially.
E M M E T T A N D GRINDLEY ON C H E M I S T R Y OF FLESH. from the samples which were held in storage for the longer period but this was so slight in some cases, considering the indirect method of obtaining this particular data, that nothing can be said regarding it. Of the total soluble phosphorus, it may be stated that, on the average, i t was slightly higher in the 43-day samples of cooked meat. A distinctive feature for the boiled and roasted meats is here shown in connection with the insoluble and total phosphorus. The former showed a gain on an average for the boiled meat from
583
be stated, when considered upon the fresh basis, that they correspond to the uncooked meats in several respects, showing that the products which were held for the longer period were richer in soluble dry substance, organic extractives, and soluble inorganic phosphorus. Nothing further can be said of this data in this form in regard to the other constituents, the variations being rather inconsistent on account of the differences in moisture and fat content. In studying the data of the cooked meats, calcu-
TABLE11. CHEMICAL COMPOSITION O F COLDSTORAGE FLESH.LEANBEEF LOIN, COOKED. (Calculated to t h e Fat-free Basis.) Description of sample
Boiled a t 85 C. 3 hours. 7
Laboratory N o . ..................... 1966-67 6 Time held in cold storage (days). . . . . P. Ct.
Soluble non-coagulable. . . . .
.........
0.28
Total
...........................
..................
Roasted at 100' C.
1991 43 P. ct. 71.13
15/8 hrs. 1979 6 P. ct. 71.78
2 1;s hrs.
1978 6 P. ct. 69.70
3.56 29.78
4.78 25.52
4.84 24.03
4.67 23.55
5.07 23.14
32.28
33.34
30.30
28.87
28.22
28.21
0.15 0.29
None 0.38
0.17 0.20
None 0.45
0.54 0.13
0.58 0.27
1989 43 P. ct. 69.91
1968-77 6 P. ct. 67.72
1990 43 P. ct. 66.66
3.95 26.14
3.12 29.16
30,09 None 0.33
0.64
0.38
0.67
1992 43 P. ct. 71.79
0.85
0.37
0.45
29.54
25.39
23,80
23.45
22.89
-5.22.
29.56
29.92
25.76
24.25
24.12
23.74
1.20 1.61
0.82 1.01
1.11 1.32
1.35 1.90
1.33 2.04
1.21 1.74
1.38 1.89
2.81
1.83
2.43
3.25
3.37
2.95
3.27
0.81 0.24
0.66 0.24
0.75 0.24
1.16 0.12
1.02 0.23
1.05 0.10
0.94 0.25
1.05
0.90
0.99
1.28
1.25
1.15
I.IQ
None 0.053
0.024 0.78
None 0.061
0.028 0.031
None 0.072
0.086 0.020
0.092 0.044
0.053
0.102
0.061
0.059
0.072
0.106
0,136
0.384
0.261
0.354
0.433
0.428
0.388
0.442
0.437
0.363
0.415
0.492
0.500
0.494
0,578
4.499
4.144
4.628
4.726
4.062
3.807
3.753
3.663
4,863
4.581
4.991
5.141
4.554
4.037
4.247
4.241
0.106
0,142 0.028
0.102 0.034
0.134 0.029
0.139 0.059
0,159 0.049
0.141 0,051
0.155 0.049
0.159
0.170
0.136
0.163
0.I98
0.208
0.192
0.204
0.081
0.102
0.080
0.105
0.081
0.071
0.066
0.056
0.272
0.216
0.268
0,279
0.279
0.258
0.260
...........................
.....
---
----
28.92
...........................
......................... ...........................
----
Roasted a t 195' C. 1 hour.
25.90
Total ........................... 28.40 Organic extractives: Nitrogenous.. . . . . . . . . . . . . . . . . . . . . 1 .OO Non-nitrogenous. . . . . . . . . . . . . . . . . . . . 1 . 3 3 2.33 Total Ash: Soluble. . . . . . . . . . 0.79 0.21 Insoluble.. ........................ Total 1.00 Nitrogen : As soluble coagulable protein
Insoluble. Total Phosphorus: Soluble inorganic
Boiledat looo C. 3 hours.
. . . . . . . . . . . . . . . . . . . 0.240
J
.33
the 43-day sample of 26.7 per cent. and for the roasted meat a loss of 13.6 per cent. On the other hand, the boiled meats from the sample which was stored 43 days were also high in total phosphorus, showing a percentage total gain of 13.0 and 21.3, respectively, for the 8 5 ° C . and 100"C. samples, while the roasted meats were almost identical in both cases. From the statements just made in comparing the cooked meats, which were obtained from samples kept in cold storage for 6 and 43 days, i t may
lated to the fat-free basis, as in Table 11, i t will be seen that they show the same general facts as just cited. Therefore, it will not be of any special interest to enter into any discussion of the figures in this connection and our attention will be directed to a study of the data calculated to the fat-free basis and thence to the same water content, as given in Table 111. Here, it will be seen that the respective cooked samples, designated as being from the meat held for 43 days, are calculated in each case to the same percentage moisture
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E : M I S T R Y .
5%
content as those for 6 days. Further, it was thought feasible to present an average of the four tests for each of these meats and thus eliminate in part the individuality, and thereby get a general deduction, if possible. The two columns a t the right of the table give these averaged data.
Chemical Composition of Cooked Bee! Loin, Calculated to the Same Water Content. I n taking up a detailed study of the constituents, the soluble dry substance showed a higher per-
Aug., 1909
of necessity, be correspondingly lower in the 43day samples. This is most pronounced for the insoluble protein, the average results for the former, the dry substance, being a decrease of I.; per cent. of the whole, and for the latter, the protein, one of 2.0 per cent. As was stated in considering the data upon the fresh basis, the coagulable protein is absent in the boiled and the gas-roasted meats from the composite 43-day cold storage samples, b u t it is
TABLE111. CHEMICALCOMPOSITIONOF COLD STORAGE FLESH,FAT-FREES U B S T A N C ELEAN . BEEF LOIN,COOKED. (Calculated t o the Same Water Content.) Description of sample.. . . . . . . . . . . . .
Boiled a t 85' C. 3 hours.
Boiledat 100' C. 3 hours.
Roastedat 195'C. 1 hour.
Roasted a t IOO'C.
--------1 "le
Laboratory N o . . . . . . , . . . , . , . , . . . . 1966-67 Time held in cold storage (days). . 6 P. ct. Water.. . . . . . . . . . . . . . . . . . . . . . . . . 68.29 Dry substance: 3.38 Soluble. . . , . . . . . . . . . . . . . . . . . . , . . . . Insoluble.. . . . . . . . . . . . . . . . . . . . . . . . 2 8 . 3 3 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 31.71 Protein: Soluble coagulable . . . . . . . , . . . . . . . . 0.10 0.18 Soluble non-coagulable. . . , . . . . . , . , . Total . . . . . . . . . . . . . . . . . . . . . . . . . . 0.28 Insoluble.. . . . , . , , . , . , . . . . . . . . . . . . 2 8 . 1 2 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 28.40 Organic extractives: 1 .OO Nitrogenous. . . . . . . . . , . . . . . . . . . . . . . Non-nitrogenous . . . . . . . . . , , . . . . . . . . 1 .33 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 2.33 Ash:
.
.
.................
0.79
1989 43
1968-77 6
P. Ct.
P. ct.
68.29
1978 6 P. ct. 69.70
P. Ct.
67.72
1990 43 P . ct. 67.72
4.16 25.55
3.12 29.16
3.45 28.83
31.71
32.28 0.15 0.49
None 0.35
Average Average of (4), of (4). 6
43
P. ct.
P. ct.
69.70
71.78
71.78
69.37
69.37
4.78 25.52
5.08 25.22
6.67 23.55
5.07 23.15
3.99 26.64
4.44 26.19
32.28
30.30
30.30
23.22
28.22
30.63
30.63
hTone
0.17 0.20
0.54 0.13
0.58 0.27
0.24 0.25
0.14 0.37
0.64
0.37
28.92
28.60
27.64
29.56
28.97
0.47
0.67
0.85
0.49
25.39
24.98
28.45
22.90
26.47
25.94
25.76
25.45
24.12
23.75
26,96
26 45 1.28 1.75
3.03
0.37
0.47
0 .;I
*u
1.26 1.70
0.82 1.01
1.08 1.28
1.35 1.90
1.40 2.14
1.21 1.74
1.38 1.89
2.96
I
.83
2.36
3.25
3.54
2.95
3.27
1.09 1.49 2,59
0.85
0.66
0.73 0.23
1.16 0.12
1.07 0.24
1 0.10
.os
0.94 0.25
0.91 0.17
0.90 0.24
0.96
1.48
r.31
I.I;
I.19
1.08
1.14
None
0.028 0.031
h'one
0.086 0.020
0.092 0.044
0.038 0.040
0.023 0.059
0.2 1 0.25 0.24 Insoluble, . , . , . . , , . . , , , , , , . . , . . . . . I.II 0.90 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 1.00 Nitrogen: None 0.024 As soluble coagulable protein. . . . . . . . 0.016 0.056 0.078 A s soluble non-coagulable protein . . . 0.030 0,056 O.IO2 Total.. . . . . . . . . , . . . . . . . . . . . . . . . . 0.046 0.404 0.261 As soluble non-protein substance.. . . 0.318 0.460 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 0.364 0.363 Insoluble. . . . . . . . . . . . . . , . . . . . . . . . 4.499 4.367 4.628 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 4.863 4.827 4.991 Ratio of non-protein to protein: 1: 0 , 1 4 1: 0 . 1 4 1: 0 . 3 9 I n water e x t r a c t . , . . . , , , . , , . , . . , . I n meats. , . . . . . . , . . . . . . . , . . . . . . . . 1: 4 . 2 9 1 : 1 0 . 9 1 1: 1 8 . 1 2 Phosphorus: 0.106 0.150 0,102 Soluble inorganic., . , . . . . . , , . . . . . . . 0.053 0.034 0.029 Soluble organic.. , . . . . , . . , . . . . . . . . . 0.136 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 0 . I59 0.179 0,106 0.080 Insoluble., , . . , , . , , , , , . . , . . . . , . , . . 0.081 0.267 0.216 Total . . . . . . . . . . . . . . . . . . . . . . . . . 0.240
.
centage composition for the samples held in storage for 43 days, varying from 23.1 per cent. in the case of the meat boiled a t 8 j ° C . to 6.3 per cent. for the one roasted a t 195OC., and gave an average gain for all of 11.3 per cent. This gain was due chiefly to the greater per cent. of nitrogenous and non-nitrogenous organic extractives in these samples but in some instances, as in the boiled meats, it was also influenced slightly by the soluble ash. Naturally, the insoluble dry substance must, I
hrs
P. ct.
27.29
0.53
'/8
P. ct.
None
1979 6
2
1992 43
0.37
1991 43
hrs
0.059
0.076
0.059
0.059
0.076
0.106
0.136
0.078
0.082
0.343
0.433
0.388
0,442
0.350
0.409
0.494
0.578
0.426
0.491
3.753
3.664
4.236
4.151
4.664
4.642
0.402
0,492
4.576
4.062
0.449 0.525 3.995
4.978
4.554
4.520
4.247
4.242
1: 0 . 1 7 I : 13.52
1: 0 . 1 9
1: 0 . 1 7
1: 9 . 5 0
1: 9 . 0 6
1: 0 . 2 7 1: 9 . 9 5
1: 0 . 3 1 1: 8 . 6 2
0.130 0.028
0.139 0.059
0.167 0.051
0.141 0.051
0,155 0.049
0,122 0.049
0.158
0.198
0.218
0.192
0.204
0,171
0.190
0,101
0.081
0.074
0.066
0.056
0.077
0.084
0.259
0.279
0.292
0.258
0.260
0.248
0.274
1: 0 . 2 2 1: 0 . 2 0 1: 12.32 1: 10.53
0.150 0.040
a trifle higher for the Aladdin roasts, being 0.54 and 0.58 per cent., respectively, for the meats from the 6- and 43-day samples. On an average, the results showed the coagulable protein to be 0.24 per cent. for the tests with the 6-day cold storage meat and 0.14 per cent. for the tests with the 43-day stored sample or almost two times as great in the former case. The non-coagulable and total soluble protein showed no consistent variations. I n some cases, they were higher
for the meats from the 43-day sample; in others, lower. The only thing that can be stated in this connection is that the slight differences in the noncoagulable protein indicate the absence of putrefactive changes in the samples kept for the longer period. The total protein showed a slightly lower per cent. for the cooked meat obtained from 4.3day sample varying from 1.2 in the gas roast to 1 . j in the Aladdin roast, making an average decrease of 1.9 per cent. for all the cooked meats. This loss, while small in relation to the insoluble or total protein, is fully accounted for in the organic extractives where the nitrogenous form shows a percentage gain for the meat kept for the longer period of 26.0, 31.7, 3.7, and 14.0, respectively, for those boiled a t 8 j 0 C. and rooo C., and those roasted a t 1 9 j o and rooo C., and where the nonnitrogenous form shows similarly a gain of 27.8, 26.7, 12.6, and 8.6 per cent., making a corresponding increase for the total organic extractives of 27.0, 29.0, 9.0 and 10.9 per cent. Averaging these three constituents for all the cooked meats, i t is seen that the nitrogenous extractives are 17.4 per cent., the non-nitrogenous 17.4 per cent., and the total 17.0 per cent. higher for the samples from the meat kept for 43 days. When i t is borne in mind that these extractives are the constituents of the meat which contribute to some extent a t least to the flavor of the cooked products and also act as stimulants to some of the gastric glands, it will be seen that these figtires have a significant value and indicate again in a decided manner the change which takes place in the ripening of meats during cold storage. Concerning the various forms of ash, little can be stated inasmuch as the changes were slight. There seems to have been a tendency for the soluble ash to be a trifle higher in the boiled meats, obtained from the 43-day stored sample, and to be lower in the corresponding roasted samples. The percentage-of insoluble ash of the boiled meats is about the same for both samples but that for the roasted meats from the longer stored sample is about double the amount of those for the 6-day. As a result of these variances in the ash of the boiled and roasted meats, the percentage of total ash in the former was slightly higher for meats held in storage for the longer period, while in the latter, i t was practically identical. What was said of the soluble, coagulable, noncoagulable, total soluble, and insoluble protein apply here for the same forms of nitrogen, as do
also the remarks relating to the non-protein nitrogen which, multiplied by 3.12, corresponds to the nitrogenous extractives. However, i t may be of interest to notice the total soluble and total nitrogen. The first form of nitrogen was distinctly higher in every case for the cooked samples from the meats which had been stored for 43 days, being for the boiled meats, 26.4 per cent. for the one cooked a t 8 j o C. and 10.7per cent. for that cooked a t 100' C., and for the roasted meats, 6.7 per cent. for the 195' C., and 17.0 per cent. for the rooo C. roast. Averaging these four, the percentage increase for the total soluble nitrogen will be found to be about 14.5 per cent. This higher percentage of soluble nitrogen was due primarily to the nonprotein form, which in part seems to have been compensated for, in considering the total nitrogen of the meats, by the decrease in the insoluble form. The second form of nitrogen, the total, was slightly lower throughout for the meats from the .p-day sample, but calculating the differences in per cent. of the total amounts, it mill be found that they ranged from 0.8 of one per cent. in the 195O C. roast, to 0.1 of one per cent. in the 100' C. roast, which brings the results within the limit of experimental error. This fact goes to show that as far as the total nitrogen is concerned the influence of hanging in cold storage was not apparent and it incidentally adds much to confirm the statement that like pieces of meat can be so cooked by the same method that the resulting data from the samples will be comparable when calculated to the proper basis. It will be of interest to note in connection with this discussion of the forms of nitrogen, the yalues of the ratios of the non-protein nitrogen to the protein nitrogen, first in the water extract and second in the meats. The data given in the table show that there were but very slight differences between the proportion of non-protein to soluble protein nitrogen in the samples which were obtained from the 6- and 43-day storage meats, being so small as to be of no dietetic or econoniic value. On the other hand, regarding the ratio of the nonprotein to the total protein nitrogen in the meat, which term includes the soluble and insoluble forms, i t will be seen that there was a distinct difference, the meats from the 43-day sample being lower throughout. For example, in the 8j0 C. boiled meat, from the 6-day storage sample, the ratio was I : 14.3, and in that from the 43-day sample i t was I : 10.9, in the rooo C. 6-day boiled
586 *
THE JOURNAL OF INDUSTRIAL A:VD ENGI1VEERING CHE-MIYTRY.
meat it was I : 18.1,and in the 43-day sample it was I : 13.5; in the 195' C. roast meat, it was 1:9.5 for the 6-day, and I : 9.1 for the 43-day sample, and finally in the 100' C. Aladdin roast, it was respectively I : 9.9 and I : 8.6 for the meats which had been in cold storage for 6 and 43 days. I n averaging all the non-protein and total protein nitrogen in the two sets of samples, the ratio of the non-protein to the total protein is I : 12.3 for the meats obtained from the 6-day sample, and I : 10.5 for the cooked meats from the sample kept for 43 days. From these data, i t seems that the nutritive value of the cooked meats which were from the sample kept in cold storage for 43 days, was lower than that from the samples which were from the meat held only 6 days. I n other words, since the total nitrogen in each case remained practically the same, the changes which took place during the hanging in cold storage were of such a nature as to modify the forms of nitrogen by increasing the extractives and decreasing the proteins. Whether the difference in the true food value of the meats was compensated for or not, by the natural inference, that the meats kept for a longer time are of a better flavor, and hence more palatable on account of the increased amounts of extractives, and therefore more digestible, is only to be conjectured, but it would seem that this deduction would be logical in the light of our practical knowledge of the subject. I n the same connection, the greater percentage of soluble inorganic phosphorus in the meat obtained from the 43-day sample, will be of interest, since the data show that this form of phosphorus in these samples was 41.5 per cent. higher in the 85' C. boiled meat, 27.4 per cent. in the 100' C. boiled meat, 20.1 per cent. in the 195' C. roast meat and 9.9 per cent. in the 100' C. roast meat, making an average increase for all the cooked meats which had been previously held in storage 43 days of 23.0 per cent. Furthermore, the boiled meats from this sample were both richer in total soluble, insoluble, and total phosphorus, while the corresponding roasted meats contained more total soluble and total phosphorus, b u t less insoluble phosphorus. From this discussion of the composition of the cooked meats, obtained from samples which were held in cold storage for different lengths of time, it is evident that many of the changes which, appeared in the results of the uncooked meats have persisted in the cooked ones, even to a more marked
Aug., 1909
extent in some cases. I n taking the average of the two, 6- and 43-day, cold storage uncooked samples, which was given in the previous paper, and that of the four cooked samples from the respective 6- and 43-day cold storage samples, it will be seen that these data, calculated as they were to the fat-free basis and then to the same water content in each of the respective cases, showed striking resemblances, indicating again the nature of the changes which took place during the hanging in cold storage, or the result of the '(ripening" of the meat. Thus, the soluble dry substance in the uncooked meat was 5.63 and 6.13 per cent. for the meats from the 6- and 43day samples, while in the cooked samples it was 3.99 and 4.44 per cent., respectively, making a percentage gain in the former case of 8.9 and in the latter of 11.3. I n the case of the insoluble protein, the raw meats for the shorter period contained 17.05 per cent. and those for the longer period 16.53, showing a percentage decrease of 3.0 per cent. while the insoluble protein of the cooked meats for the corresponding periods were 26.47 and 25.94 per cent., making a decrease of 2 . 0 per cent. Similarly, the total protein showed a percentage loss in the uncooked meats of 2 . 0 and in the cooked meats of 1.9. As regards the organic extractives, the cooked meats from the samples which had been in cold storage for 43 days showed a greater increase for the nitrogenous form, a less one for the non-nitrogenous form, and practically the same one for the total, than did the cooked meats: the nitrogenous form, calculated in per cent. of the total, being 17.4 per cent. for the cooked and 12.5 per cent. for the uncooked; the non-nitrogenous form being 17.4 per cent. for the cooked and 20.7 per cent. for the uncooked ; and finally the total extractives being 17.0 per cent. for the cooked meats, and 17.3 per cent. for the uncooked meats. Of the forms of nitrogen not dwelt upon indirectly in considering the proteins and extractives, that of the total soluble is of interest. I n the uncooked meats, i t showed a gain for the 43-day sample of 8.8 per cent. while in the cooked meats from this sample, this increase amounted to almost double that of the uncooked, being 14.7 per cent. The ratio of the soluble non-protein nitrogen to the total soluble protein nitrogen shows nothing more in the one case than in the other; however, the difference in the ratios of the non-protein nitrogen to the total protein nitrogen in the meat appears
more markedly in the cooked than in the uncooked broths and drippings as well as the percentage samples. For example, the ratio of the forms of loss in cooking are given in detail, calculated in nitrogen in the case of the cooked meats from the per cent. of the uncooked meats. First, taking 6-day stored sample of loin was I : 12.3 and in up the matter of the gross loss which resulted that for those from the meat which was held in from the boiling or roasting of the samples, i t will storage 43 days i t was I : I O . j , whereas i t was be seen from the data that all of the 43-day refrigerated, cooked, samples weighed more than I : 9.1 and I : 8.1, respectively, for the 6- and 43day uncooked meats. The percentage gain of the 6-day refrigerated, cooked meats, and theresoluble inorganic phosphorus was about the same fore that the total losses were correspondingly in both the uncooked and cooked meats, being less in the two sets of meat. Calculated in per cent., in the former 20.3 and in the latter 22.9. Com- the gross losses of the 43- and 6-day samples were paring the other forms of phosphorus, the differ- respectively for the meats boiled a t 8 j o , 24.07 ences in the case of the individual uncooked meats and 29.12; for those boiled a t 100" C., 31.66 and were not consistent throughout. However, in 32.86; for those roasted a t 19j" C., 17.08 and 22.04; comparing the average of the constituents of the and for those roasted a t 100" C., 14.24 and 16.37, cooked meats with those of the corresponding un- the whole making an average percentage loss of cooked samples, i t is seen that the total soluble ,21.76 and 2 j . I O , respectively. Those figures show phosphorus in both cases showed about the same a difference between the two meats ranging from relative distribution and differences between the 1 . 2 1 per cent. in those boiled a t 100" C. to 5.05 6- and 43-day samples, being for the uncooked per cent. in the samples bo led a t 8 j " C., or in 0.171 per cent. for the former, and 0.203 per cent. considering the average, a difference of 3.34 per for the latter, and for the average of all the cooked cent. The fact that each of the 6-day samples meats from these samples 0.171 and 0.190 per cents., of meat showed a greater or less tendency to lose respectively. The insoluble phosphorus, on the more upon cooking than did the 43-day samples, other hand, showed a decrease for the sample would seem to he pretty good evidence that the from the 43-day storage meat of 80.1 per cent. longer period of hanging caused sonie change in the uncooked loin, while there was an increase in the chemical nature or physical structure of of 9.1 per cent. in the cooked meats. Further, the meat which prevented the passage of as great the total phosphorus in the raw meat held in storage a percentage of some of the constituents into for the longer time was I j . 4 per cent. less than that the broths or drippings. It will be of interest to study this point more for the meat kept for the 6-day period. I n the cooked meats, the total phosphorus showed a gain in detail and in so doing, the chemical nature of for samples from the meat which was held in storage the losses resulting from the cooking will be considered. I t is evident that the losses just noted, 43 days, of 1 0 . 5 per cent. refer to the cooked meats themselves and that, Chemical Composition of the Broths and Drippings, in reality, the so-called losses in cooking are genand the Losses Resulting p o r n Cooking erally utilized as broths, in the case of the boiled the i2leats. meats, and as gravy or drippings, in the case of I t will now be of interest to study still further the roasted meats. Therefore, the chemical comany differences which might have been the result position of the broths and drippings must be conof the influence of cooking the two kinds of meatsidered in getting an insight into the detailed losses. the 6- and 43-day stored samples. Here, the per- Referring to this same table, IV, it will be centage loss in cooking, the composition of the seen that the composition of the broths and dripbroths and drippings, the coniposition of the meats pings is presented in exactly the same form as that when compared directly with the broths and drip- for all the meats which have been studied thus pings, the proportional distribution of the various far. This fact is of importance in that a much constituents which passed into the broths and clearer insight can be had of the actual changes drippings, and also those which remained in the which take place in the cooking than if only the cooked meats, all seem to have a bearing upon usual gross determinations were reported. the effect of the length of time of hanging meats The first apparent differences in the nature in cold storage. of the losses is in the percentage of water. This I n Table IV, the chemical coniposition of the term is somewhat general in that it refers to all
T H E JOURiVilI, OF I.\TDLr.STRIAI,
588
of the loss, other than that obtained as dry matter in the broths or drippings. I n the case of the meats which were kept for the 43-day period, the losses from the cooked products showed that they contained less water, varying from 0.75 per cent. for the 100' C. boiled meat to 4.81 for the roast meat, and giving an average of 3.09 for all four tests. This indicates a t once that the greatest difference in the total or gross loss was due to moisture, and if this be calculated, i t will be found t h a t 92.5 per cent. of the difference in the gross loss between the 6- and 43-day meats was actually due to the constituent water. In the case of the dry substance, the differences were not so great, but yet considering the total amounts in each case, they were sufficient to state that the soluble and insoluble forms showed a lower percentage content throughout for the 43day samples, averaging for the fornier a decrease over the loss in the 6-day sample of 10.5 per cent. and for the latter, one o€ 30.2 per cent., and making
one of 15.9 per cent. for the total dry substance, The decrease of 10.5 per cent. in soluble dry substance seems to have been distributed in approximately the same proportion among the various soluble constituents, the proteins, the extractives and ash, so that it did not seem to produce any special difference in any one of the instances, For example, in the case of the boiled meats, the soluble protein of the broths seems to have been slightly lower while in the roasted meats the extractives of the drippings showed the greater percentage decrease. The average loss of 30.4 per cent. in the insoluble dry substance for the meats from the sample which was kept 43 days in storage was due chiefly to the lower percentage of f a t which showed a loss varying from 39.3 per cent. in the 195' C. roast sample to 65.4 per cent. in the 100' C. boiled meat and averaging 60.0 per cent. for all the broths and drippings. Aside from the insoluble and the soluble forms of the constituents that have been considered
TABLEIV.
CHEMICALCOMPOSITIONOF COLDSTORAGE FLESH. LEANBEEF LOIN, COOKED. (Calculated in Per cent. of the Uncooked Meat.) Description of sample . , , , , , . , , , . . , , .
Boiled a t 85' C. 3 hrs.
------
Boiled a t 100'C. 3 hrs.
1978 6 P. c t .
1991 43 P . ct.
hrs. 1979 6 P. ct.
41.40
49.63
53.86
54,93
2)/3hrs. 1992 43 P . Ct. 56.22
1.91 24.08
2.17 25.69
3.41 25 . 3 5
3.67 25.75
3.57 25.51
3.97 26.05
25.99
27.86
28.76
29.42
29.08
30.02
0.09 0.30
Pione 0.23
0.12 0.14
h-one 0.34
0.41
None 0.22
1989 43 P. ct.
1968-77 6 P. c t .
43.66
47.86
2.16 25 .30
2.70 25 38 28.08 None 0.23
27.46 0.07
Total . . . . . . . . . . . . . . . . . . . . . . . . . .
..............
..........................
Total Organic extractives: Nitrogenous. . , , , , . . Non-nitrogenous.. . . Total ..........................
Insoluble.
........................
As soluble protein.. . . . . . . . . . . . . . . . As soluble non-protein. . . . . . . . . . . . .
Total. .........................
0.11 0.IS
.------
Roasted a t 100' C. 77
1990 43 P. ct. 40,6R
7-A-
Laboratory N o . . . . . . . . . . . . . . . . . . . . . 1966-67 Time held in cold storage (days). . , , 6 E'. ct.
Soluble. . . . . . Insoluble. . , . Total. . . . . . . . . . . . . . . . . . . . . . . . . . Protein:
--
Roasted a t 195 C. 1 hr.
1518
0.10
0.23
0.26 18.08
18.02
17.95
17.92
18.06
18.02 18.25
18.34
18.36
18.46
18.59
0.82 1.10
0 .so 0.62
0.68 0.80
0.96 1.36
1.01 1.54
0.93 1.33
1.48
f .48
1.92
I.I2
I
.48
2.3.2
2.55
2
.a6
2.56
7.19
7 .48
6.26
7 .52
7.19
7.56
7.48
7.93
0.50 0.14
0.55 0.17
0.40 0.15
0.83 0.08
0.77 0.17
0.80 0.08
0.74 0.19
0.64
0.72
0.55
0.46 0.14 0.60
0.91
0.94
0.88
0.93
0.029 0.203
0.036 0.263
0.062
0.037 0.216
0.299
0.222
0.253
2.838
2.829
2.884
0.081 0.297 0,378 2.872
0.106 0.346
0,232
0.042 0.308 0,350 2,892
0.055
0.160
3 .I37
3.051
3.737
3,242
3.250
3.320
1: 0 . 3 9 1: 18.0
1: 0 . 1 7 1: 13.5
1: 0 . 5 5 1: 9 . 5
1: 0 . 1 7
1: 0 . 2 7
1: 0.31
1: 9 . 1
1: 9 . 9
1:8 6
0.663 0.020
0.082 0.018
0.099 0.042
0.120 0.037
0.108
0.122 0 .e38
0.23
0,39
17.97
17.73
17.67
18.15
17.96
0.64 0.84
Insoluble, ........................ 2.876 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 3.208 Ratio of non-protein to protein: I n water e x t r a c t . , . . . . . . . . . . . . . . . . . 1 : 0 . 1 4 I n m e a t s . . . . . . . . . . . . . . . . . . . . . . . . . 1: 1 4 . 3 Phosphorus: Soluble inorganic. . . . . . . . . . . . . . . . . . 0 . 0 6 8 0.034 Soluble organic. . . . . . . . . . . . . . . . . . . . 0 . I02 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 0.052 Insoluble. ........................ Total . . 0 , I54
1: 0 . 1 4 1: 1 0 . 9
0.097 0.019
0,34
0.324
0,379 2.882 3.261
0.51
0.039
0
67
1 .os
0.452 2.868
0.116
0.083
0.100
0.141
0 .I57
0.147
0.160
0.070
0.049
0.063
0.058
0,054
0.050
0.043
0.136
0.132
0.163
0.199
0.2II
0,197
0.203
EMMETT A N D GRINDLEY ON C H E M I S T R Y OF FLESH
589
TABLE IV-(Continzled). CHEMICAL COMPOSITION OF COLDSTORAGE FLESH.BROTHAND DRIPFINGSFROM LEANBEEF LOIN, COOKED (Calculated in Per cent. of the Uncooked Meat.) Description of sample
...............
Boiled a t 100° C. 3 hours.
Boiled a t 85' C 3 hours. 1989 43 1000.00 759.31
1968-77 6 1000.00 671.36
1990 43 1000.00 683.39
1978 6 1000.00 779.61
1991 43 1000.00 829.22
240.69 24.07
328.64 32.86
316.61 31.68
220.39 22.04
170.78 17.08
163.69 16.37
142.43 14.24
P . ct.
P . Ct.
P . ct.
P. Ct.
P. ct.
P. C t .
P. ct.
22.43
29.92
29.17
21.33
16.52
15.67
13.66
1.40 0.24
2.09 0.86
1.93 0.56
0.36 0.35
0.29 0.27
0.55
0.35
0.15
0.46 0.12
1.91
1.64
2.95
2.49
0.71
0.56
0,70
0.58
0.02 0.24
None
0.02 0.36
Laboratory N o , .................... 1966-67 Time held in cold storage (days) . . . 6 Weight of uncooked meat (grams) . 1000.00 Weight of cooked meat (grams)... . . . 708.84 Gross loss in cooking: I n grams.. ....................... 291.16 29.12 I n per c e n t . . . . . . . . . . . . . . . . . . . . . . . P. ct. 27.22 W a t e r . . ........................... D r y substance: 1.56 Soluble. . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Total . . . . . . . . . . . . . . . . . . . . . . . . . . Protein: Soluble coagulable. . . . . . . . Soluble non-coasulable.. . . Total. . . . . . . . . . . . . . . . . Insoluble. . . . . . . . . . . . . . . . . . . . . . . . . Total. , . , . , . , , , . , . , . . Organic extractives: Nitrogenous. . . . . . . . . . . . . . . . . . . . . . . Non-nitrogenous . . . . . . . . . . . . . . . . . .
.
.................
-
Roasted a t 100' C. 7 -
1 310 hrs. 1979 6 1000.00 836.31
c
....................
Roasted a t 195'C. 1 hour.
7
None
0.26
0.19
0.38
0.33
0.08
0.12
0.05
0.03
0.34
0.31
0.43
0.36
0.19
0.40 0.57
0.37 0.58
0.48 0.74
0.97
0.95
0.27
0.12
0.51 0.77 I.28 0.81
0.34 Soluble. . . . . . . . . . . . . . . . . . . . . . . . . . . Insoluble, . . . . . . . . . . . . . . . . . . . . . . . . Total . . . . . . . . . . . . . . . . . . . . . . . . . . 0.34 Nitrogen: As soluble protein.. . . . . . . . . . . . . . . . 0 . 0 4 1 As soluble non-protein. . . . . . . . . . . . . 0.126 Total soluble., . . . . . . . . . . . . . . . . . 0.167 0.012 Insoluble, . . . . . . . . . . . . . . . . . . . . . . . . Total . . . . . . . . . . . . . . . . . . . . . . . . . . 0.179 Ratio of non-protein t o I n water extract. . . . . . I : 0.33 Phosphorus: Soluble inorganic. . . . . . . . . . . . . . . . . . 0 . 0 4 1 Soluble organic. . . . . . . . . 0.024 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 0.065 Insoluble. . . . . . . . . . . . . . . . . . . . . . . . . Total .......................... 0,065
......
0.33
None 0.13 0.13 0.06
0.19
None
None
0.11 0.II 0.10
0.19
2 1,'s hrs. 1992 43 1000.00 857.57
0.02 0.19
0.19
0.21
0 .os
0.09
0.21
0.27
0.30
0.05 0.09
0.04 0.07
0.08 0.16
0.06
1.22
0.14
0.II
0.24
0.16
0.28
0.28
0.17
0.06
0.03
0.10
0.12
0.09
......
......
0.06
0.I2
0.09
0.018 0.014
0.030 0.025
0.031 0.020
......
......
......
0.10
0.06
0.27
0.43
0.37
0.IO
0.030 0.117
0.061 0.165
0.053 0.155
0.020 0.014
0 .I47
0.226
0.208
0.034
0.032
0.055
0.05I
0,019
0,008
0.004
0.010
0.015
0.014
0.015
0.166
0.234
0.212
0,044
0.047
0.069
0.066
0.27
0.43
0.37
1: 0 . 2 6
1: 0.37
1: 0 . 3 4
1: 1.43
0.043 0.011
0 055 0 026
0.057
0.011
0.014
0.006
0.054
0 081
0.071
0.017
. . ...
0.054
thus far, those of the nitrogen are of importance. The nitrogen of the drippings, from the roast meats, showed but very slight differences between the 6- and 43-day samples. The broths, however, showed the percentage of soluble protein nitrogen, the soluble non-protein, the total soluble and the total nitrogen to have been lower for the 43-day meats, on an average 18.6, 6.j , 9.7, and 8.4 per cent., respectively. The insoluble nitrogen varied. but slightly and even then, inconsistently, and therefore showed nothing of value. The ratio of the soluble non-protein nitrogen to the soluble protein nitrogen showed no differences in the boiled meats and none in the roast meats which would indicate anything as to the nature of the losses due to length of time of storage. The forms of phosphorus showed some interesting facts concerning the losses in cooking in connection with this study. This was especially
0 OSI
......
0.071
1: 1.25
1: 1 . 1 8
1: 1.56
0.013 0.007
0.014
......
0.011 0.003 0.014
......
0.020
0.005 0 .or9
0.017
0.014
0.090
0 .OIQ
true of the inorganic form which, contrary to all our previous discussion relative to the meats, did not show any noticeable differences in the case of the broth and drippings from the cooked meats obtained from the 6- and 43-day stored samples. The organic form which showed a greater percentage for the 6-day meats also showed a like state of affairs for the broths and drippings. When the total soluble phosphorus is considered, the 43-day samples were distinctly lower for the broths and but slightly lower for the drippings, averaging a decrease of 13.7 per cent. for all. Having now considered the nature of the losses in detail, it will be of interest to compare them with the cooked meats, calculated upon the same basis, that is, in per cent. of the uncooked meats. I n this way a further insight can be gotten as to the influence of the length of time of storage upon the cooking of meat.
590
THE JOURLVAL OF I-VDUSTRIAI, A-\I'D EAVIGI.VEERILVGCHEM1.YTRI'.
The fact that 92.j per cent. of the gross losses in cooking the meats was due to loss of moisture and that the meats from the 43-day samples lost less in cooking, would lead one to expect a higher percentage moisture content for these cooked meats. This condition appears to have existed in the case of the roasted meats and the ones boiled a t 8 j o C., but in the case of the 100' C. boiled meats, there was a loss in favor of the samples from the 6-day storage meat, amounting to 0.72 per cent. Averaging all four of the tests, i t was found that the meats obtained from the 43day cold storage sample contained 2.24 per cent. more of water, or a total gain of 4.7 per cent., and it would therefore seem, as previously stated, that the cooked meats, from the samples kept in storage for the longer time, tended to be juicier. The percentage of soluble dry substance of the samples from the 43-day storage meats was distinctly higher in every case, and it is significant to note that while the broths and drippings showed a corresponding decrease, yet this did not account for the entire gain. For example, in the meats boiled a t 85' C., those from the 6-day sample contained 2 . 1 G per cent. of soluble dry substance and those from the 43-day sample 2 . 7 0 per cent., making a difference of 0.54 per cent. or a percentage gain of 25.0. On the other hand, the broths from these meats showed the soluble dry substances to have heen 1 . j 6 per cent. in the meats from the 6-day sample and 1.40 per cent. in those from the 43-day meats, making a difference of 0.16 per cent. as compared with the 0.54 per cent. of the meats themselves. If allowances be made for this compensating percentage of 0.16, the cooked meats obtained from the 43-day storage sample still show a gain of 0.38 per cent. or 17.6 per cent. of the amount in the fresh 6-day samples. Applying this analogy to all the meats, the average showed the percentage of soluble dry substance to be respectively for the 6- and 43-day samples, 2.76 and 3.13 for the meats and 1.14 and 1.02 for the broth and drippings or an increase of 0.37 per cent. in the former and a decrease of 0 . 1 2 in the latter. This fact shows that the cooked meats from the 43-day storage sample were richer in soluble dry substance than those from the 6-day sample, even if no allowance was made for the greater percentage of water which the meats from the 43-day samples contained. I t will be seen a t a glance, upon considering the organic extractives, that they were the individual soluble constituents
Aug., 1909
which cause the main differences. I t will be recalled that the percentage of nitrogenous, nonnitrogenous, and total extractives were very nearly the same in the broths and drippings, obtained in cooking the meat from the 6- and 43-day storage samples, the latter showing the greater percentage loss for the 43-day samples. In the cooked meats, however, there was a decided percentage increase of the forms of extractives for the samples from the 43-day meat. This is more noticeable in the boiled than in the roasted ones. I n the former the greatest percentage gains were in the 100' C. boiled meats for the nitrogenous and total extractives, being 36.0 and 32.0 per cent., respectively, and in the 85 O C. cooked samples for the non-nitrogenous 31.0 per cent., and the 100' C. boiled for the total extractives 32.0 per cent. In the case of the roast meats, the average of the two tests showed that the samples from the 43-day storage meat were I O . j , 11.9, and 11.8 per cent. richer in nitrogenous, non-nitrogenous, and total extractives, respectively, than were those from the 6-day sample. If the two kinds of meat, the boiled and the roasted, the averaged, i t will be seen, after deducting for the difference in the broth and drippings, that the nitrogenous extractives were 1 j . 7 per cent., the non-nitrogenous 15.3 per cent. and the total 16.2 per cent. higher in the cooked meats from the 43-day sample. I n connection with such deductions as are apparent from the study of the forms of the extractives, i t would be of interest to note the nature of the forms of protein in the cooked meats. It will be seen, as stated previously in another connection, that the cooked meats from the 43-day cold storage loin sample was lacking in coagulable protein, in the case of the boiled meats and in that roasted a t 19j' C. The samples roasted a t 100' C. showed about the same percentage of the coagulable protein in the tests with the 6and 43-day uncooked loin samples. If an average .be made of all the meats, i t will be found that the meats from the 6-day samples contained 0.17 per cent., and that those from the 43-day sample 0. I I per cent, The non-coagulable protein showed a tendency to be higher in meats from the 43-day sample. I n the 100' C. boiled meats, this form of protein was slightly lower, being for the sample kept in storage 6 days 0.30 per cent., and for the one kept 43 days 0.23 per cent. The average of all the values showed a percentage of 0.16 for the sample from 6-day meats and 0.25 for that
from the 43-day samples. Associating with this fact, that on the average the non-coagulable protein was higher and the coagulable protein was lower in the cooked samples from the meats which were kept in cold storage for the longer period, with the fact that the uncooked meats when calculated to the fat-free and same moisture content were practically alike in these constituents, i t seems T-ery probable that during the process of cooking, the hydrolytic action was carried further with the samples from the 43-day cold storage meat and changed a part or all of the coagulable protein to the non-coagulable form. ,\nd if this statement is connected with the fact that the extractives were also higher, i t is evident that the hvdrolysis went beyond the protein stage and formed a greater percentage of the non-protein bodies. Kow comparing the percentage of the total soluble protein, the d a t a show t h a t the samples kept for 43 days were higher in the case of the meats boiled a t 8 j 0 C. and also the meats roasted a t 195' C., and 100' C., being 27.8, 30.8, and 31.4 per cent., respectively. On the other hand, the meat boiled at 100' C. showed a loss of total soluble protein for the sample obtained from the 43-day meat amounting to 41.0 per cent. of the total percentage in t h a t from the 6-day sample. The average of all four meats shows a gain for those from the 43-day storaye samples of 9.7 per cent., which, considering the small percentage of total soluble protein, actually amounts to only 0.03 per cent. of the samples themselves and therefore is of little nutritive significance. The percentage of insoluble protein showed b u t a slight difference between the various cooked meats kept for the two periods of storage. The greatest variation appeared in the case of the 100' C. boiled meat where the meats from the 43-day sample contained 18.02 per cent. and those from the 6day sample 17.67 per cent., making a difference in favor of the former of 0.35 per cent. If the percentage of insoluble protein for all the samples for each period be averaged, i t will be found that they were both the same, 17.92 per cent. The percentage of total protein was exceptionally close in each case in comparing cooked meats from the 6- and 43-day samples. The greatest differences were not over 1.0per cent. of the amount determined and thus within the limit of the errors of the methods. It is therefore seen from the above discussion that there was very little differ-
ence between the actual nutritive values of the resulting cooked meats from the samples which were kept in cold storage for 6 and 43 days. However, i t will be of interest in this connection to study the various forms of nitrogen. What has been stated regarding the total soluble protein, nitrogenous extractives, and insoluble protein applies to these forms of nitrogen since each was simply multiplied by its conventional factor, to transform i t to the above condition. Of the other forms of nitrogen, the total soluble of the cooked meats was higher in each case for the samples from the 43-day meat, ranging from 8.3 per cent. in 195' C. roast meat to 28.8 per cent. in the 8 j o C. boiled meat, and averaging for the four tests 16.9 per cent. The total nitrogen of the meats was b u t slightly higher for the samples kept in storage for the longer time, varying from 0.6 per cent. of the total amount in the 19jO C. roast to 2.8 per cent. of t h a t in the 100' C. boiled meat. Further, the ratio of the non-protein to the soluble protein nitrogen in the two classes of meats did not vary enough to be of any significance as to the influence of the length of time of storage, but in the case of the ratio of the soluble non-protein nitrogen to the total protein nitrogen, as was stated previously, the boiled meats showed a decided difference between the samples which were obtained from the 6- and 43-day cold storage meat, and the roast meats showed a similar, though less pronounced difference. In each of the cases, the ratio was less for the sample which was stored for the longer period, being respectively for the 6- and q,-day tests, for the meats cooked in water a t 8 j o C. I : 14.3 and I : 10.9; for those cooked a t 100' C., I : 18.0 and I : 13.j ; and for those cooked by dry heat a t 195' C., 1 : 9 . j and I : ~ . I and ; for those cooked a t 100' C., I : 9.9 and I : 5.6. These data, regarding the forms of proteins, extractives, and nitrogen, indicate a t first glance that the influence of cold storage resulted in producing cooked meats which were less nutritious when held in storage 43 days than when held b u t the 6 days, but bearing in mind the fact that the percentage of insoluble and total protein of the respective cooked meats were practically the same for those obtained from the 6- and 43-day samples, and also the fact that the percentage of nitrogenous organic extractives for non-protein nitrogen was higher for each of the samples from the 43-day meat, i t will become evident why the ratios varied as they did and therefore it will be seen that the
592
T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHELWISTRY.
cooked meats from the sample which was held in storage for the longer period were just as nutritious as those held for the shorter time, and also, that they were of a better flavor, due to the increased quantity of organic extractives. The next constituents which should be considered are the f a t and the forms of ash and phosphorus. The first showed a higher percentage content in the case of the cooked meats from 43-day samples varying from 5.1 per cent. in the 195' C. roast, to 2 0 . 1 per cent. in the 100' C. boiled meat, and upon averaging for all tests an increase of 8.4 per cent. In the percentages of soluble ash the variations for the boiled meat from the cold storage sample which was held 43 days showed a gain of 10.0per cent. for the 85' C., and one of 15.0 per cent. for the I O O O C., and for the roast meats, they indicated a loss of 7 . 2 per cent. for the 195' C. sample and one of 7.5 per cent. for the 100' C. sample. The insoluble ash for the boiled meats was about the same in the two cases b u t in the roasted meat, those from the 43-day stored sample were over twice as high in this form,
Aug., 1909
being for the I g j o C. roast 0.08 and 0.17 per cent., and for the 100' C. roast 0.08 and 0.19 per cent. for the samples from the 6- and 43-day cold storage meats, respectively. The percentage of total ash was somewhat higher in eveky case for the meat from the longer stored sample, being lowest in the 1 9 j o C. roast, 3.3 per cent., and highest in the 85' C. boiled sample, 1 2 . 5 per cent., and averaging for all 7.0 per cent. The soluble inorganic phosphorus of the cooked meats which were from the 43-day sample showed a greater percentage content throughout than did those from the 6-day sample, being least for the 100' C. roast, 13.0 per cent. of the total amount, and greatest for the 85' C. boiled meat, 42.6 per cent., and averaging for all the four samples a gain of 24.5 per cent. This fact is of special note inasmuch as it will be recalled that the losses in cooking, the broths and drippings, showed no marked difference in this constituent, the meats from the 6-day samples containing no more inorganic phosphorus than did those from the 43day samples. On the whole, little, if anything,
TABLEV. PROPORTIONAL DISTRIBUTION OF THE NUTRIENTS I N THE COOKEDMEATS DUETO COOKINGLEANBEEFLOIN. (Calculated in Per cent. of the Total Amounts in the Uncooked Meats, by Summation.) Description of sample. . . . . . . . . . . . . . . . . . Boiled at 85 C. Boiled at 100' C. Roasted at 195 ' C Roasted,at 100°C. 3 hours. 1 hour. Average 3 hours. 7 1 5 / 6 hrs. 2 '1s hrs. of (4). Laboratory No 1966-67 1989 1968-77 1990 199 1 1979 1992 1978 43 6 43 43 Time held in cold storage (days). . . . . . . . 6 43 6 6 6 P. ct. P. Ct. P. ct. P.ct. P.ct. P. ct. P.ct. P.ct. P.ct. 80.45 66.85 61.60 68.09 76.52 77.80 Water.. .............................. 58.05 58.24 69.94 Dry substance: 70.74 86.65 89.62 52.93 65.85 92.67 Soluble.. ............................ 58.10 47.75 90.45 98.31 99.54 99.42 . . . . . . 98.64 99.06 98.96 96.55 98.64 97.87 98.11 g I .a0 89.81 94 63 94.48 98.13 97.64 97.59 Protein: 95.75 89.90 None 100.00 None 100.00 Soluble coagulab 81.82 None 53.64 48.55 51.85 65.52 54.76 41.07 75.56 Soluble non-coag 45.45 72.86 Total. 66.67 76.14 55.27 45.24 50.65 41.07 75.56 99.50 99.63 99.67 99.45 99.56 Insoluble. ...... . . . . 99.56 99.33 99.72 99.85 Total ............................. 98.16 98.08 98.41 98.34 98.56 98.30 97.68 98.97 98.87 Organic extractives: 94.74 74.54 92.08 Nitrogenous. ......................... 61 .54 68.91 49.50 58.62 95 .OS 96.19 71.81 89.26 93.67 65.48 93.80 44.60 51.95 95.65 Non-nitrogenous, ..................... 59.60 . . . . . . . . . . 60.41 66.90 46.67 90.40 9 4 .I 2 72.95 54.82 94.31 95.87 99.62 95.08 99.21 97.80 88.50 96.41 98.42 96.25 Ash: 70.98 92.77 86.96 89.16 67.07 89.25 55.42 48.19
---
.......................
....
.......
Nitrogen: As soluble protein.. . . . . . . . . . . . . . . . . . . As soluble non-protein. . . . . . . . . . . . . . . . Total ............................. Insoluble. . . . . . . . . . . . . . . . . . . . . . . . . . . .
. Soluble inorganic. .................... Insoluble. . . . . . . . . . . . . . . . . . . . Total .............................
Average of (4).
....
43 P. ct. 70.82 75.27 98.86 95.63 23.94 56.26 59,50 99.53 98.41 79.59 76.69 77.93 98.06 76.10
.....
.....
.....
.....
.....
.....
.....
.....
72.73
56.12
61.86
90.IO
94.00
88.00
91.18
74.88
79.94
41.27 61.75 58.13 99.57 94.54
54.82 69.19 67.06 99.34 94.98
50.64 49.23 49.62 99.71 92.89
41.11 58.22 54.88 99.86 93 .67
67.36 95.56 90.98 99.65 98.63
75.55 95.80 92.24 99.47 98.57
73.26 92.23 87.38 99.52 97.94
77.48 94.59 89.91 99.48 98.06
58.13 74.69 71.53 99.61 96.00
62.24 79.57 76.05 99.54 96.32
62.39
69.29 63.33 68.24
53.39 43.48 50.61
58.99 56.25 58.48
90.00 87 .50 89.24
91.60 92.50 91.81
89.26 84.78
88.02
89.70 88.37 88.39
73.76 68.59 69.99
77.39 75.11 76.73
77.50
61.97
69.66
9 2 .I 3
93.78
90.78
91.44
78.80
83.09
.....
70.32
.....
.....
.....
.....
.....
.....
.....
.....
E,lIA,IETT AiVD GKIL'IILEY OLV CHEAk!15TI?Y OF F L E S H .
5 93
TABLEV-(Confznued) DISTRIBUTION O F THE NUTRIENTS I N THE BROTHS A N D DRIPPINGS DUETO
I'ROPORTIONAL
Description of sample. , . , . . ,
.
,
. .. ,
Boiled a t 85 C . 3 hours.
,
...................
P.Ct.
2 ],'a hrs. 1992 43 P . ct.
30.06
23.47
22.20
19.55
47.07 2.13
9.55 1 36
7.33 1 .04
13 .35
I0.IQ
8.20
2.41
1.87
2.36
10.38 0.46 1.89
None 45.24
18.18 54.55
None 58.93
Sone 48.15
59.09
45.24
49.35
58.93
33.33
0.44
0.67
0.28
0.15
0.33
Sone 24.44 24 44 0.55
1.70
2.33
I.92
1.03
1.13
31.09 34.52 33. I0 1.58
50.50 55.40
41.38 48.05
53.33
45.18
11.50
3.59
4.95 6.20 5.69 3.75
51.81
44.58
1968-77
38.40 41 . 9 3 1.36
.
.
....
.
___A____
1978 6
P. ct.
1990 43 P. ct.
31 . 9 1
41.95
41 76
52.25 3.45
6.50
31.15 0 .94 5.52
22.20 68.60
I 84 T o t a l . , ....................... Organic extractives: Nitrogenous, ..................... 38.46 Son-nitrogenous . . . . . . . . . . . . . . . . . 4 0 . 4 0 To t a l . , , , , , . . . . . . . 39.547 Fat, .., , , , . . . . . . . 3.62 Ash: Soluble. . . . . . . . . . . . . . . . . . . . . . . . . . 40.48 Insoluble, . . , , , , , , , . , ......... Total. . . . . . . . . . . . . . . Sitrogen: 4 s soluble p r o t e i n . , . , . . . . 58.73 As soluble non-protein. . . . . 38.25 Total soluble.. . . . . . . 41.87 Insduble. . . . . . . . . . . . . . . . . . . . . . . . 0.43 Total . . . . . . . . . . . . . . . . . . . . . . . . . j.46 Phosphorus: Soluble inorganic.. . . . . . . . . . . . . . . . 3 7 , 6 1 Soluble organic. . . . . . . . . . . . . . . . . . . . 4 1 . 3 8 Total. . . . . . . . Insoluble, . , , , , Total ......................... 29.68
. ..
LEASBEEFLOIN. Roasted a t IOO'C. i5,6 hrs. 1979 6 P. et,
1989 43 P . Ct.
.
...................
-----.
COOKING
Roasted a t 195' C. 1 hour. 1991 43 P. Ct.
_ A _ _
Laboratory S o .. . . . . . . . . . . . . . . . . . . 1966-67 6 Time held in cold storage (days). , , , P. ct. Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . Dry substance: Soluble. . . . . . . . . . . . . . . . . . . . . . . . . . Insoluble. . . . . . . . . . ....... Total. . . . . . . . . . . . ....... Protein : Soluble coagulable. . . . . . . . . . . . . . . . .... Soluble non-coagulable
Boiled a t 100° C . 3 hours.
32.93
6
.....
.....
27.27
43.88
45.18 30.81
49.35 50.77 j0.38 0.29
32.93 0.66
5.26 6.33
4.13
9.60
j.88
2.20
0.79
0 38
13.04
10.84
0.44 I
7 23
.....
38.14
0 YO
6.00
12.00
32 64 4.44
24.45 4.20
26.74 7.77
22.52 5.41
45.12
9.02
7.76
12.62
10.09
0.35 1.37
0 53
0.48
0.52
.43
2.06
1.474
8 40 7.50
10.74 15.22
10.30 11.63
8.19
rr.98
10.61
58.89
41.78
30.71 36.67 31.76
46.61 56.52
41.01 43.75
10.00 12.50
49.39
4r
I O 76
-72.50
38.03
30.34
can be said regarding the soluble organic phosphorus, other than that the general tendency indicated a slight decrease in those obtained from the 43day meat. Inasmuch as the soluble inorganic form is distinctly higher in the sample from the 13-day cold storage meat and the organic form is about the same, i t is natural to expect the conditions which existed in regard to the total soluble phosphorus. Here, the differences in favor of the meat kept in storage for the longer peiiod varied from y . 0 per cent. of the total amount in the I O O O C. roast to 2 O . j per cent. in the 100' C. boiled meat and gave an average of 1 2 . 7 per cent. for all the cooked samples. The percentage of insoluble phosphorus was higher in the case of the boiled meats obtained from the 43-day storage sample, averaging 31.7 per cent., but in the case of the roasted meats there was b u t little difference. Finally, the total phosphorus appears to have been more in abundance in the cooked meats from the samples which were held in cold storage for the longer period. In the case of the Aladdin 100' C. roast, the greater percentage amounted to only 3.0 per cent. of the total quantity, while
7.92 10.74
2 7 . I4
.....
7.II
.....
3.81 4.35
34.48
10.75
02
......
.44
4.25 46.36 23.86 0.50 I .59
None
.....
0.14 6.33
j
0.58
52
..... 7.87
I
.....
.....
.....
6.22
9.22
8.82
..... 8.56
in the rooo C. boiled meat, it reached as high as 23.5 per cent., and if the average of all four samples be considered, there was a total phosphorus content which was 11.8 per cent. greater than that of the 6-day cold storage sample.
T h e Proportional Distribution of the Nutrients in Cooked Meats. Having considered in detail the nature of the cooked meats, calculated to the various forms, and also the broths and drippings, i t will be instructive to study briefly the percentage distribution of the nutrients in each case, that is, assuming the sum of the constituents in each meat and its corresponding broth or dripping to be equivalent to the original uncooked sample, an approximation as to the differences in the nature or character of the two meats can be obtained by calculating the proportion of the various constituents in the uncooked and samples. In taking the sum of the respective constituents as being the equivalent of the uncooked meat, instead of using the direct analysis of the raw loin cut itself, a much better comparative set of data will be had throughout,
5 94
T H E JOL7RdVALO F INDUSTRIAL A*VD E2VGIi\-EERING CHE,UISTR Y .
since i t will be recalled that during the process of cooking, the percentage of coagulable, non-coagulable, soluble and insoluble protein, the corresponding forms of nitrogen and the soluble and insoluble dry substance were so altered that a proportional relation of these forms in the cooked and uncooked meats obtained directly would be meaningless for this comparison. The data in Table lr show the results expressed as above described, for the meats, broths and drippings. However, inasmuch as the statements which are to be made in regard to the meats apply in a reciprocal manner to the respective broths or drippings, the discussion will be confined to the first item alone. First, i t will be seen that on an average, the longer stored meats after cooking contained a greater percentage of their original moisture than did those which were kept for the shorter time, being 70.82 and 66.85 per cent. respectively. I n the case of the 100' C. boiled meats, this difference was very slight, but in the other three cases, i t was quite pronounced, varying from 2.65 per cent. in the 100' C. roast to 6.58 per cent. in the 195' C. roast. Further, the boiled meats showed that they retained approximately two-thirds of their water while the roast meats retained about threefourths. The fornis of dry substances indicated several interesting facts. Of the total ar,ount of the soluble form in the uncooked meats, the cooked samples from the 4g-day storage meat held a larger percentage. The average of all the tests showed that the meats from the 6-day samples contained 70.74 per cent. and that those from the 43-day samples contained 75.25 per cent. of the total amounts in the respective uncooked samples, making a difference of 4.51 per cent. The maximum variation in the 85' C. boiled meats was 7.75 per cent., and the minimum variation in the 195' C. roast meats was 2 . 2 2 per cent. The insoluble dry substance showed but very slight differences in the proportional amounts, averaging 98.31 and 98.86 per cent. for the four tests froni the 6- and 43-day meats. The total dry substance gave practically the same results as the insoluble form, showing that the meats from the 43-day storage sample contained 1.0 per cent. more of the total amount in the uncooked sample. Comparing the boiled and roasted meats, the proportional amounts of soluble, insoluble and total dry substance averaged 56.10, 93.03, and 92.39 per cent. for the former
Aug., 1909
and 89.85, 99.14, and 97.87 per cent. for the latter. I n the case of the various proteins, the soluble coagulable form was noticeably higher in the samples from the 6-day stored meats, ranging from 100.0 per cent in the roasted meats to 77.80 per cent. in the 85' C. boiled meat. The samples from the 43-day stored meats showed that this form was apparently coagulated to a greater or less exte'nt, during the process of cooking. I n each case, except in the 100' roast, there was no soluble coagulable protein. The average of all tests showed that cooked samples from the meat kept for the shorter time still retained 89.9 per cent. of the original amounts, while those from the meats which were kept for 43 days still contained only 23.9 per cent. The non-coagulable protein showed that the cooked meats froin the sample which was kept for the longer time, tended to lose less of their initial amount of this form than did the ones which were obtained from the meat stored for 6 days. The 100' C. boiled meats were a n exception to this statement, but the average of all the tests indicated that samples from the 43-day stored meat contained j6.3 per cent. and that those from the 6-day sample contained 48.5 per cent. of the amounts in the respective uncooked meats. The same general statements which were just made in connection with the non-coagulable protein apply to the total soluble protein. The average of the soluble protein for all the respective experiments was 59.5 per cent. and 57.3 per cent. for the cooked meats from the 43- and 6-day Samples. The insoluble protein showed but a very slight variation between any two of the cooking experiments, I n fact, the differences were so small for the insoluble protein that i t can be stated that the time of storage has no influence upon this constituent, the average being 99.63 per cent. for the cooked sample from the 6-day meat, and 99.53 per cent. for that from the 43-day meat, with a maximum difference of 0.23 in the 8 j 0 C. boiled meats, and a minimum one of 0.06 in the 100' C. roasted meats. Again, the proportion of total protein in the various cooked meats was practically the same in each of the four cases, being on an average for the samples stored for 6 days 98.34 per cent., and for those kept for 43 days 98.41 per cent. The organic extractives indicated consistent variations throughout, which appeared to be due to the effect of the time of storage. In the case of the nitrogenous form, the boiled meats which were
c.
E M M E T T A N D G R I I i D L E Y 0-V C H E M I S T R Y OF F L E S H . procured from the 43-day uncooked samples contained on a n average 8.20 per cent. more of these extractives than did those from the 6-day sample, while the corresponding roasted meats contained 1.9 per cent., making an average difference of 5.05 per cent. for all the cooked meats. The percentage of non-nitrogenous extractives in the cooked meats from the 43-day stored sample also indicated that these meats lost less during the process of cooking, averaging for those from the 43-day meat 76.69 per cent., and for those from the 6-day meat 71.81 per cent., making a difference of 4.88 per cent. The proportional amounts of the total extractives showed that the cooked meats from the samples which were kept for the longer time were the higher, averaging for all the tests a difference of 4.98 per cent. I t is of interest to note a t this point, again, the influence of the method of cooking upon the quantity of some of the constituents which were removed: in the boiled meats about 43 per cent. and in the roasted meats about 6.0 per cent. of the total amount of the extractives in the uncooked meats passed into the broths and drippings respectively. I t will also be of special interest to note that the amount of crude fat was higher in each case for the samples froni the 43-day storage meat, the greatest difference being in the 100' C. boiled sample 7.91 per cent. Averaging all the cooked meats for the 6-day sample showed that they lost in cooking 2.98 per cent. more of the fat than did those from the 43-day meat. The soluble ash as well as the total ash both showed the same tendency as t h e fat, namely, to be higher in the meats from the 43-day sample. I n the case of the soluble form, the greatest differences were in the boiled meats, being '7.55 per cent. in the 85' C. cooked meat, and the smallest ones were in the roast meats, being 2 . 2 0 per cent. in the case of the Aladdin 100' C. cooked meat. The average of all tests gave a difference of j . 1 2 per cent. in favor of the cooked samples from the 43day storage meat. The total ash in the 85' C. boiled meat from the sample stored for 43 days, indicated that of the original amount in the uncooked meat, 72.73 per cent. was retained during the cooking, while in the case of the corresponding 6-day samples, the amount was 6j.31 per cent., making a difference of 7.42 per cent. In the Aladdin roast, the same tendency seems to have been apparent b u t to a less extent, being 91.18 and 88.00 per cents. respectively for the samples from the 43- and 6-day meats, and showing a differ-
595
ence in favor of the former of 3.18 per cent. Averaging all the four tests, there was a variation of j.06 per cent., showing that the samples from the longer stored meat lost less of their total ash content during the process of cooking than did those which were from the sample kept for the shorter period, 6 days. The total soluble and total nitrogen indicated in the former case that the cooked meats obtained from the 43-day stored sample retained the greater percentage of the original amount in the uncooked meat: The 85 ' C. boiled meats showed the greatest difference in the total so1,uble form, being 8.93 per cent., and the 195' C. gas-roasted meats showed the smallest difference, 1.26 per cent., averaging for all the tests a gain of 4.52 per cent. The proportion of total nitrogen was about the same in each of the four tests with the samples from the 6- and 43-day stored meats. There was a slight tendency in favor of the sample from the longer stored meats, being in the maximum case, the 100' C. roast, 0 . 1 2 per cent. Averaging all tests, there was a difference of 0.32 per cent. I t is noteworthy that the roast meats showed almost no influence due to the time of storage. The average of both roast meats gave 98.28 per cent. for the meats from the 6-day sample and 98.31 per cent. for those from the 43-day sample. In the case of the boiled meats, the differences are greater than for the roasted ones, yet not very large, considering that over 93.0 per cent. of the nitrogen was retained in the cooking. The average of the two boiled meats gave 93.72 per cent. for cooked meats from the 6day sample and 94.32 per cent. for those froni the 43-day sample, making a difference of 0.60 per cent. The forms of phosphorus represented, the solublc inorganic, soluble organic, total soluble and total, all showed to a greater or less extent that the cooked meats from the 43-day stored sample retained more of these constituents during cooking than did the ones from the 6-day meat. The respective percentage averages were for the cooked meats from the 6- and 43-day samples 73.76 and 77.39 per cent. for the inorganic, 68.59 and 75.11 for the organic, 69.99 and 76.73 for the total soluble, and 78.80 and 83.09 for the total, making a difference in each instance of 3.63 per cent., 6.j2 per cent., 6.71 per cent. and 4.29 per cent. As in the case of the total nitrogen, the boiled meats indicated the greater influence from storage. This fact was especially true with the inorganic and total soluble forms of the phosphorus.
SUMMARY.
Having now considered in detail the chemical composition of the cooked meats, both in per cent. of the fresh substance and the uncooked meats themselves, the nature of the losses and the proportional distribution of the various constituents in the cooked meats and the broth and drippings which resulted from the boiling and roasting of the samples of lean beef loin which had been held in cold storage for 6 and 43 days, the following summary shows the effect which seems, in these cases, to have been produced during the interval of 37 days of storage. First, from the chemical examination of the cooked meats, obtained from the respective 6- and q-3-day storage samples, the average data in each case show, when calculated to the fat-f ree basis and then to the same moisture content, that the cooked meats from the longer stored sample contained, when compared with those from the 6-day sample, I 1.3 per cent. more of soluble dry substance, 41.6 per cent. less of coagulable soluble protein, practically the same percentage amount of total soluble protein, and 1.9 per cent. less of total protein; that the percentage of the nitrogenous and non-nitrogenous organic extractives were each 17.4 higher; that the ash content was about the same; that the percentage of total soluble nitrogen was 14.7 per cent. higher while that for the total nitrogen was but 0 . 5 per cent. lower; that the percentage of the soluble inorganic, the total soluble and the total phosphorus were respectively, 22.9, 11.1, and 10.5 per cent. higher and that the ratio of the soluble non-protein nitrogen to the total protein nitrogen was I : 12.3 for the samples from the 6-day meat and I : 10.5 for those from the 4g-day meat. Second, the composition of the cooked meats calculated in per cent. of the uncooked showed in general: that of the samples obtained from the 6- and 43-day stored meats, those from the latter lost 3.34 per cent. less during the process of cooking; they contained 2.24 per cent. more of water and hence were juicier ; their soluble, insoluble, and total dry substance showed a percentage increase over the 6-day meat of 13.4,2.5, and 3.7 per cent. respectively ; the percentage of insoluble and total protein were practically the same as those in the 6-day samples ; the nitrogenous, non-nitrogenous and total organic extractives were respectively 15.7, 15.3, and 1 j . 5 per cent. greater; even after allowing for the differences in the broth and drip-
pings, the f a t showed an increase amounting to 8.4 per cent. of the total in the samples from the 6-day meat; the percentage of total ash was 7 . 0 per cent. greater; the soluble inorganic and the total soluble phosphorus showed percentage gains which were respectively 24.5 and 12.7 per cent. of the total amounts in the other samples; and the total soluble nitrogen was 16.9 per cent. higher, while the percentage of total nitrogen was about the same as in the meat from the 6-day sample. Third, the proportional amounts of the various nutrients which were retained in the corresponding cooked saniples from the 6- and 43-day cold storage meats, showed the following facts in regard to the saniples which were from the meat that was kept in cold storage for the longer time: Of the total amounts of constituents found by summing the composition of the respective cooked meats and the corresponding broths and drippings, these meats retained on an average 3.97 per cent. more of water: 4.53 per cent. more of soluble dry substance; 5.05, 4.88, and 4.98 per cent. more of nitrogenous, non-nitrogenous, and total organic extractives respectively; 2.98 per cent. more of f a t ; 5.12 and 5.06 per cent. more of soluble and total ash; 3.63, 6.52, 6.74, and 4.29 per cent. more of soluble inorganic, soluble organic, total soluble and total phosphorus respectively. Further, these meats lost practically the same proportional amounts of the insoluble and the total forms of dry substance, protein and nitrogen as did those from the 6-day sample, being respectively for the cooked nieats from the 43- and 6-day samples 98.86 and 98.31, 95 63 and 94.63, 99.53 and 99.63, 98.41 and.98.34, 99.54 and 99.61, and 96.32 and 96.00 per cent. I n comparing the boiled and roasted meats, i t was seen that in every case where there was any appreciable difference between the storage samples, the former cooked meats showed the effect to a greater degree. Finally, it may be stated in general: That, many of the differences between cooked meats from the samples which were held in cold storage for 6 and 43 days, corresponded to those which were found to exist for the uncooked refrigerated samples. That the cooked meats from the 43-day storage sample lost less in cooking either by boiling or roasting than did those from the 6-day sample, the broths and the drippings in these cases being on the average lower in their percentage content of soluble, insoluble, and total dry substance, of organic extractives, of soluble protein, of soluble ash, and of fat.
ADDRESSES. T h a t the cooked meats from the longer stored sample were higher in their percentage content of moisture and were therefore juicier, higher in soluble and insoluble dry substance, in nitrogenous, non-nitrogenous and total organic extractives, in f a t , in total ash, and in soluble inorganic, total soluble and total phosphorus. Further, the percentages of total nitrogen, insoluble and total protein were practically the same as were those for the samples from the 6-day storage meat. Therefore the cooked meats from the 43-day samples, judging from the chemical composition, were a t least as nutritious as were those from the samples stored for the shorter period of time. The authors wish to acknowledge the valuable assistance of JSiss E$. C. Sprague and Messrs. J . M. Barnhart and L. F. Shackell in connection with the analytical work.
597
Mississippi, Louisiana and Texas; the Sorway pine or red pine in Michigan, Minnesota and the Province of Ontario; and the Douglas fir in TVashington, Oregon and British Columbia. I n any one of the three cases the raw material may be especially selected resinous wood, or i t may be sawmill refuse. Susr~-miLl Rejuse.---This consists of slabs, edgings and sawdust. (The amount of refuse varies much with the size of logs, sizes of lumber cut, and kind of saws.) The slabs and edgings are passed through a n edging grinder o r chipper and cut into chips of about the size used in making paper pulp. The total of chips and sawdust is not far from 2 0 0 cubic feet per 1000 feet of lumber sawed. -1s a cord of wood when reduced to chips of uniform size occupies zoo cubic feet or over we niay say that a sawmill cutting 100,000 feet of lumber a day will have the equivalent of nearly 100 cords refuse or \Taste material. In most sawmills the sawdust furnishes sufficient fuel and the other refuse is burned. X large number of patents have been granted on processes and apparatus for the destructive distillation of this waste material, in the form of chips or sawdust. So far as the writer knows no one of them has ever reached the stage of 1-RBANA, ILLINOIS, actual manufacture, because sawdust and chips are such April 3. 1909. ___-poor conductors of heat that more or less complicated mixing devices are necessary to accomplish the distillation and the ADDRESSES. yields obtained do not warrant the expense of installation and repairs. The only method of treating sawmill waste PINE PRODUCTS FROM PINE WOODS.' on a manufacturing basis has been steam distillation. The chips or sawdust or both are brought by conveyors By J O H N E. TEEPLE,PH.D. to storage bins, from which they are dropped into retorts. The last year or two have been disastrous to the industry These retorts are usually cylindrical affairs made of boiler of recovering pine products from pine wood in .4merica. For more than five years the Savannah price of turpentine iron and have ~oo-joo cubic feet capacity. If set horizontally a helicoid screw conveyor or other device is had not fallen below fifty cents per gallon, and had been steadilv strengthening each year, not fluctuating greatly, used for discharging the chips after the treatment. If set vertically the bottom is arranged as a door to drop or slide rising a little in winter and falling a little in summer as the away and allow the chips to fall, sometimes with the aid of new crop came into the market. I n 190; the price for a shakers operated by hand. n'here only sawdust is used there time exceeded seventy cents per gallon a t Savannah. These apparently firm conditions of the market for so long a time is no difficulty in discharging a large vertical retort through encouraged all sorts of experiments and ventures in tur- a n 18-inch or two-foot hole in the bottom. Another type of retort is a cylindrical or spherical one hung on trunnions. pentine recovery. The records of the patent office for these Whatever the shape of the retorts, they are provided with years reflect the general confidence in the future of the steam pipes perforated for the admission of live steam, industry, in the form of scores of patents on possible and and distributed throughout the retort in such manner as the impossible processes and apparatus for the extraction of designer thinks will give most complete extraction of turturpentine, rosin and other products from pine wood. pentine from the chips. The retort being filled, live steam Plants multiplied throughout the South, a t costs varying is turned on for one-half hour to one hour in the case of from $3,000 or S4,ooo u p to $IOO,OOO or more. The total sawdust and for one to t w o hours in the case of chips. This number of such plants of all descriptions must have been nearly 100. The number in actual operation to-day is extracts most of the turpentine and some of the pine oil. Distillation and rectification with steam separate the prodprobably less than I O , and very few of these claim to be uct into wood spirit of turpentine and pine oil, the only financiallv successful at the present price of turpentine, tvvo products obtained from mill waste. Quite a number From seventy cents or more per gallon the price of turof recovery plants of this type have been built particularly pentine declined steadily during rgo; to about 50 cents a t the end of the year, and to 3j cents after the middle of 1908; in Florida, but careful inquiry seems to show only one in since then i t has been below 40 cents most of the time, All- actual operation a t the present time. This is one designed b y the writer for a sawmill in Florida. The other ones most a n y type of plant could operate successfully a t 7 5 have apparently met their fate from fire, low price of turcents per gallon; nearly every one is a source of regret a t 40 pentine, financial considerations, or faults in construction cents per gallon. xhich made i t necessary to use labor in handling the refuse Three diilferent \roods have been used as raw materials wood a t some stage of the process. The amount of wood of the industry, uiz., the long leaf pine (Pinus pulustris) in to be handled is so large and the yield of turpentine so small, S o r t h Carolina, South Carolina, Georgia, Florida, Alabama, comparatively, that hand labor must be reduced to a 1 Presented to t h e Seventh International Congress of Applied minimum or the plant cannot operate. Chemistry, 1909.
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R E'. The yields obtained from sawmill waste are subject to many fluctuations. Where all the timber has been boxed for turpentine before being cut for lumber the slabs are very rich and the yield is uniformly good. There seems to be a regularity in the changing yield, however, probably depending in part on the season a t which the logs are cut, and in part on imperfect condensation in summer. During the winter months a yield of about one and one-half gallons refined product to IOO cu. ft. chips or sawdust is the rule. I n summer, particularly in July and August, it may fall to one-half that amount or less. Since the raw material costs nothing we have to consider only the daily labor and expense charges, and interest, insurance, depreciation and taxes. The daily labor and expense charges usually lie between ten and twenty cents per gallon in a properly constructed plant, depending of course on the yield. The average cost including all charges should lie between twenty and thirty cents per gallon in a sawmill cutting a t least IOO,OOO ft. per day. ,4 plant should hardly be installed in connection with a smaller mill, One other form of utilizing sawmill waste may be mentioned. A plant has been operating in Texas in which shavings from a planing mill were converted into paper pulp, from which a very good grade of brown paper was made. I n the preliminary digestion a small amount of turpentine is recovered. As far as I know mill waste from the long leaf pine is the only kind whose recovery has been attempted commercially in this country. Light W o o d - By far the most important raw material in the pine products industry is the light wood, a name given t o the non-decaying resinous parts of the dead long leaf pine trees. The formation of this material and the general development of the industry have been traced in another place.' 'CVe have to deal here only with the present condition of the plants. This light wood is found wherever long leaf pine grows in the eight southern states mentioned above. The largest quantities and best quality are found in turpentine orchards that have been worked for many years and finally abandoned. If boxed trees have afterward been cut for timber the stumps are very rich down to three or four inches below the level of the ground. Exclusive of short stumps about one or two cords of light wood may usually be obtained per acre. The light wood is usually c u t into four-foot lengths for convenience in handling, but in one plant a t least it was the custom to bring in whole logs 8-16 feet in length and feed them directly into the edging grinder. Hand labor is used exclusively in cutting and preparing the light wood. The wood from stumps is no different from ordinary light wood, excepting that it averages a little richer in turpentine and is more expensive to prepare for the plant. At some plants stumps are sawed off near the ground level, then split by hand. A t others a charge of dynamite was placed in the tap root just below the ground level. This splits the stumps so that very little further labor is required. A third method is to use the stump puller, but in this case the wood must be split by hand and carefully freed from stones and gravel, before i t goes to the edging grinder. Prepared in any of these ways great care must be used in the selection of the light wood going to the 1
J. Soc. Chem. Ind., 26, 811 (1907)
A u ~ .I,909
plant. A cord of light wood may yield anywhere from 6-30 gallons of turpentine. The men who are working with it regularly become very expert in judging its quality, and as the cost of good light wood is not greatly in excess of that for poor wood this skill becomes a valuable asset. For good light wood, yielding an average of 15 gallons turpentine per cord we may consider $2.50 per cord a minimum and S4.jO per cord a maximum price delivered a t the plant. Given good lightwood a t the plant there are three general methods of dealing with it, viz., steam distillation use of a bath, and destructive distillation. These will be considered separately. Steam Distdatzon.-&lore plants of this type than of any other have been constructed during the last five or six years. The simplicity of the process and the large amount of turpentine t h a t could be made in a day were its recommendations. The plants consist essentially of an edging grinder to reduce the light wood to chips, storage bins and retorts like those discussed under the sawmill waste, conveyors to handle fresh and extracted chips, boilers, engines, condensers and refining stills and tanks. The chipped J
