BROM’.VE 0.V T H E C‘SE OF TE,\!lPERATURE
CORRECTIO-VS.
56 7
Color Reactions of Aconitine. C. REICHARD. Compensating Polariscopes Therefor.’’ I n this paper Pharm. Centralh., 46, 476. i t was demonstrated by numerous experiments 58. Alkaloidal Valuation of Aconite Root. that for each degree C. increase in temperature the CAESARA N D LORETZ.Report, Sept., 1905, 101. polarization of pure cane sugar on quartz wedge Pharm. Certralh., 46, 860. saccharimeters decreased 0.03 O Ventzke Wiley 59. Contributions to Our Knowledge of the accordingly advocated that the readings of a11 Aconite Alkaloids. Part XVI. Indaconitine, the Alkaloid of Aconitum Chasmanthum. quartz-wedge compensating polariscopes made a t DUNSTASX X D ANDREWS. Jour. Chem. Soc., temperatures other than standard be corrected 1905, 1620. by means of this factor, and constructed a tahle of 60. Contributions to Our Knowledge of the temperature corrections for polarizations between Aconite Alkaloids. Part XVII. Bikhaconitine, the Alkaloid of Aconitum Spicatum. D U X S T A N 75’17. and 100’1’. for temperatures between 4‘ C. A X D ANDREWS.Jour. Chem. soc., 1905, 1636. and 40’ C., these corrections to be subtracted from 61. Contributions to Our Knowledge of the the observed polarizations when the temperature AND Aconite Alkaloids. Part XVIII. DUNSTAN of observation is below and to be added when the HENRY. J o u r , Chem. SOC.,1905, 1650. temperature is above that a t which the instrument 62. Variability in Potency of Aconite Root. was standardized. de CHEVALIER A N D BARDET. Bull. G&. Therap. (Paris), 1905 [ I ~ o ]713. , A t the fourth meeting of the International Con63. On the Aconitine and Aconine from Aconitum gress of Applied Chemistry, held in Paris in 1900, Napellus. H. SCHULZE.i l r c h i z . d. Pharm., Wiley’ presented another paper upon “The Cor244, 136. rections of Polariscope Readings for Changes 64. On the Aconitine and Aconine from Aconitum in Temperature” in which he showed the magniNapellus. H. SCIIULZE.Archil. d. Pharm., 244, 165. tude of the variations produced in polarizations 6 5 , A New Reaction of Aconitine. N. &‘IONTI. with different types of saccharimeters and the corGar. cham. ital., 36 [ 2 ] , 477. rections necessary to restore the correct reading. 66. Assay of Aconite Root. H. M. GORDIK. A t this same meeting of the Paris Congress PYOC.A . Ph. A , , 1906, 379, 6 7 . Alkaloids in Aconite Root. F. WEN‘J.HRUP. Wiechmann2 presented a paper upon the “QuesAbstract in Pharm. Jour. [4],23, 627. tion of Temperature Influence on the Specific 68. The Aconite Assay of U. S. P. VIII. -4.B. Rotation of Sucrose” in which he opposed the LYOSS. Am. Drug., 1908,89. views of Wiley. Wiechmann in his paper reviewed 69. Modification of the U. S. P. Method for niost critically the results of all previous invesAlkaloidal Valuation of Aconite Root and H. BERSEGXU. A m . ]Our. Preparations. tigations upon the subject and cited numerous Pharm., 1909, 1 2 2 . experiments of his own upon the polarization j;.
1906.
1907. 1908. 1909.
LABORATORIES OF P A R K E .
‘
DAVIS & CO.
THE USE O F TEMPERATURE CORRECTIONS I N THE POLARIZATION O F RAW SUGARS AND OTHER PRODUCTS UPON QUARTZ WEDGE SACCHAR1METERS.l By C. A. BROWNE. Received M a y 2 2 , 1909.
I. INTRODUCTIOS. Kumerous papers have been presented at past meetings of the International Congress of Applied Chemistry upon “The Influence of Temperature upon the Specific Rotation of Cane Sugar.” At the third meeting of the International Congress held in Vienna in 1898 M’iley2 first read a paper upon “ T h e lnfluence of Teniperature on the Specific Rotation of Sucrose and Method of Correcting Readings of Read before Section V . Seventh International Congress of Applied Chemistry, London, May. 1909. 2 Proc. T h i r d Inter. Cong A g p . Chaw.,Vol. 11,p . 407, J . Am. Chem. Soc., 21, 568 (1899).
of pure sucrose solutions, from which he concluded t h a t chemically pure sucrose does not change its specific rotatory power with change in temperature and that no corrections should be made therefor in technical sugar analysis. A t the same meeting of the fourth International Congress a third paper upon “The Influence of Temperature on the Specific Rotation of Sucrose” was read by Pellat3 who found as a result of his investigations that there was a progress ve decrease in the specific rotation of sucrose with increase in temperature, the mean coefficient of variation between 14’ and 30’ being 0.00016. If we add to this value of Pellat for the temperature coefficient of sucrose the temperature coefficient4 0.000148 for the quartz compensation and 1
3
Proc. Fourth Inter. Cong. A p b . Chem , Vol. 11,p. 142. I b i d . . Vol. 11, p . 145. I b i d . , Vol. 11, p. 135. Value determined by Schonrock, Z e d . Ver. Deut. Zucker. Znd.. 41.
tech. teil., p . 521.
, 568
.
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 J I I S T R Y .
scale we obtain the coefficient 0.000308, or for 100' Ventzke 0.0308, which is the same as the figure of Wiley. The presentation of the papers of Wiley and Wiechmann a t the Paris Congress, before the International Conimission for Uniform Methods of Sugar Analysis, was followed by a long discussion, as a result of which it was generally agreed that, while the adoption of temperature corrections was not deemed advisable, sugar solutions should be made u p to volume and polarized a t a standard temperature of 20' in order to remove all influences of error. The International Commission also passed the resolution that for countries whose temperature is higher than 20' saccharimeters may be adjusted at 30' or any other desired temperature providing that. the analysis of sugar be made a t the same temperature. At the meeting of the fifth International Congress of Applied Chemistry held in Berlin in 1905, the question of the influence of temperature upon the specific rotation of sucrose was again discussed b y Schonrock' in a paper entitled "The Dependence of the Temperature Coefficient of the Specific Rotation of Cane Sugar upon Temperature and Wave-length.'' Schonrock showed as a result of most careful physical measurements that the coefficient of the specific rotation of cane sugar was as follows: 6Fo=-0.0002 42, S,D,= -o 000I 84, =-0. ooo I z I. The value of 6 decreases with increase of temperature. For quartz wedge saccharimeters the above values for 6 must be increased by 0.000148,the temperature coefficient for the quartz compensation and nickelin scale. The total correction calculated to 100' Ventzke is then 10' C. = o.03g0, 20' C. = 0,0332, 30' C. = 0.0269. The average factor between 20' C. and 30' C. is 0.0300which is identical with the figure found by Wiley. The influence of temperature upon the polarization of sucrose has, however, niore than a theoretical interest. I n the United States a t least the question has been studied largely for the purpose of introducing greater accuracy in the polarization of raw sugars. The Treasury Department of the United States as a matter of fact incorporated in its Regulations of October 27, 1897,a method of correcting the influence of temperature upon the polarizations of all sugars imported into the United States and 1 Proc. FifthZ m t a . Cow. A g g . Chem.. Vol. 111, p. 100.
Aug., 1909
assessed for duty. The method of the Treasury Department consists in correcting the polarization of each sugar by the variation in reading which a standardized quartz plate will show from the computed sucrose value of this plate for the temperature of observation. Owing to the fact that the average daily temperature of most laboratories in the United States is above 20' this method of correction necessitates in almost every case a n addition to the observed polariscopic reading. The right of the U. S. Treasury Department to make any additions to the observed polarizations of sugars' was contested in the Courts by various importers of sugar, who held that any increase of temperature occurring in practice does not reduce the rotation of the sugar solution in the polariscope, nor does otherwise produce a lower test than that which would be obtained a t any lower temperature occurring in actual practice, and that the assertion of some experts and the denial b y others of the existence of any such alleged influence of temperature upon the rotatory power of sugar did not justify the Secretary of the Treasury in requiring additions to be made to the observed polariscopic test of imported sugars prescribed by law, and so increasing the rate of duty payable upon then1 above that prescribed by law. The importers in. their petition furthermore contested the right of the Treasury Department to hold that the polariscopic test means " t h e percentage of pure sucrose contained in sugar as ascertained by polarimetric estimation." The protest of the importers against the Treasury Regulations was overruled by 'the Board of General Appraisers in March, 1899. An appeal was accordingly taken to the Circuit Court which re versed, in May, 1903, the judgment of the General Appraisers, although expressing the opinion2 that " despite the vehement protests and expert testimony on the part of plaintiffs to the contrary, the contention of the government"-(that there is a decrease in the reading of the polariscope with increase in temperature)--" is sustained by the preponderance of proof." I n this reversal of the previous decision Judge Townsend of the Circuit Court made the following statement :3 " The point has not been made on the argument, and it is perhaps irrelevant, but no reason is perceived why, if the government desires to secure uniformity and 1 For particulars and testimony in this case see Tramcrzgt of Record, U.S.Supreme Court. 2 Federal Regorter, la3.329 (Aug. 13, 1903). Federal Regorter, 123, 330 (Aua. 13, 1903).
BROWATE ON T H E USE OF T E M P E R A T U R E CURRECTIUSS. accuracy, i t should not take its tests, or provide t h a t they should be taken, a t the temperature at which its instruments are standardized." This judgment of the Circuit Court was afterwards reversed in June, 1904, b y the Court of Appeals' and the previous decision of the Board of General Appraisers sustained. The importers made a final appeal to the United States Supreme Court who dismissed the case on November 30, 1908, for want of jurisdiction. The final decision of the Courts sustaining the Regulations of the U. S. Treasury Department in applying temperature corrections to the polarization of raw sugars settles the question no doubt once for all so f a r as Constitutional objections are concerned. R u t so far as scientific objections are concerned the case is far from settled. There are inherent difficulties in the application of temperature corrections to the polarization of raw sugars, molasses, massecuites, and other sugar house products. As a matter of fact when we cease to deal with pure sucrose the temperature correction employed by the Treasury Department in the assessment of sugar duties no longer corrects; in other words the corrected polariscope reading is not always the same as would be obtained upon this same product under the standard conditions of temperature. I t is a matter of some surprise that in the case of the importers against the United States, which involved the correctness of the polarizations of raw sugars, no experiments showing the influence of temperature upon the optical rotation of raw sugars were presented. The experiments submitted as evidence of the correctness of the Treasury Department Regulations were all made upon pure sucrose. The polariscopic test of a sugar, direct polarization, degree polarization, degree Ventzke, or whatsoever term i t may be given, is a conventional expression representing the combined optical activities of the various ingredients present under certain prescribed conditions. The test cannot be construed to mean " the percentage of pure sucrose contained in the sugar" as held by the Treasury Regulations (Sec. 79, 1897; Sec. 49, 1907) except in the case of pure sucrose or in the case of a very small class of raw sugars where the optical activity of the sucrose is not influenced b y the impurities present. The polarization is made to be sure upon a scale standardized to read IOO when the sugar polarized is 100 per cent. pure sucrose, but the polarization of a Federal Regorfer, 131, 833 (Oct. 13, 1904).
569
raw sugar upon this scale no more indicates the actual percentage of sucrose than i t does in the case of molasses, honey, commercial glucose, condensed milk, or any other of the numerous products which are examined b y means of a saccharimeter. To apply temperature corrections established for pure sucrose to the polarization of all substances whatsoever that are examined upon a saccharimeter would of course be a n absurdity; the temperature correction to be applied will vary according to the nature of the substance examined. It is perhaps superfluous to point out the error of the Treasury Regulations in considering " the degree of the Ventzke scale. . . . . . . . a s indicating the correct percentage of sucrose." (Treasury Regulations, Oct. 27, 1897, Sec. 79.) A few analyses of some Louisiana sugar-house products made b y the writer in 1905 may be quoted, however, in passing. TABLE I. (Showing difference between polarization and sucrose of sugar-cane products.) Direct polarization Sucrose 20° C. b y Clerget. D e n e e V. Per cent. Difference.
Product. Sugar..
........
.......... .......... .......... ..........
'' " " "
........
Syrup.. Massecuite..
.... Molasses ....... ....... .......
.....
c
"
........
93.70 89.50 82.60 74.70 72.40 54.35 60.90 58.35 41.30 34.00 28.90 16.00
94.50 90.70 85.60 78.40 76.30 58.50 64.60 62.25 45.45 37 .so 37 .05 26.90
Invert sugar. Per cent.
0.80 1.20 3 .OO 3.70 3.90 4.15 3.70 3.75 4.15 3 .80 8.15 10.90
3.62 4.60 8.82 12.74 11.92 12.20 13.72 14 .50 11.72 14.27 27.43 27 .05
-4 more complete exhibit of the difference between the direct polarization and sucrose content of raw sugars is given in Tables IV and XI. It will be noted that the polarizations of sugarcane products are in all cases much smaller than the percentage of sucrose, this difference increasing with the percentage of invert sugar present. The specific rotation of invert sugar according to Landoltl using Gubbe's formula for a I O per cent. solution is-24.21 a t 5", - 2 0 . 0 2 at zoo, and-16.81 a t 30'. Calling $66.5 the specific rotation of sucrose, i t is seen that one part of invert sugar neutralizes the optical power of 0.364 part sucrose at 5 O , 0.301 part sucrose a t zoo and 0.253 part sucrose a t 30'. The average of the results in the previous table shows that one part of invert sugar neutralizes the optical activity of 0.31j part sucrose, "Das Optische Drehungsvermogen." 2nd Edit., p. 526.
BROCl'iVE O N T H E U S E OF TEiVPER.4 T G R E CORRECTI0,V.S.
. .. . . ... . . .
Wiley . . , . Crampton.. . , Austin . ,,. Morton.. . . , . Tittman.. , ., , . Braid.. . . . , , Huntington . ,
..
0,0287
(Given as testimony ;n the Transcript of Record Supreme Court of the United States. October Term, 1908. No. 3 The American Sugar Refining C o m pany of New York, Appellant
0.0308 0.0307
The 1-nited States.)
0 . 0 3 14
0.0297 0.0305 0.0298
vs
.
Average, . . . . 0.0302 Of other values established ior this constant may be mentioned. 0.030 0.029 0.030 0.030 0 . 0 3I
Andrews (TechnoZogy Q w r t e r l y , May, 1889). Tlte U .S. Coast and Geodetic S v w e y . prjilsen Geerligs ( . A r--nief voor de Javu Suikerindustrie. July, 1903). Francis ( R ~ o r fofs Chem., British Guiana, 1883 and 1886). ~i'iiicsand Tempany (West Indiarz Bull., Vol. V I I , p , 140).
The values found by Schonrock and Pellat for this constant have been reported in the earlier part of this paper. The above value has also been confirmed by the writer who found for the average decrease in polarization between 15' and 35' for each degree C. increase in temperature, the following results for 5 different sugar solutions: TABLE11. (Showing Influence of Temperature upon Polarization of Sucrose Solutions.) Polarization of solution 20' C. 200 mm. tube.
Calculated decrease by formula 0.0003P.
100
Decrease in polarirationfor each I C. increase. 0.031
90 70
0.026 0.019
50 20
0.014
0.027 0.021 0.015 0.006
v.
0.002
0.030
The observed values agree closely with those calculated by the formula except in the case of the 20" V. solution where there may have been some slight experimental error. The writer, whose method will be described in the next section, performed his work upon weighed portions of the same solution (26 grams sucrose to IOO grams solution) so that accidental variations in the composition of the weighed sample are excluded. Whether the calculated correction for the temperature influence should be still further corrected for some slight variation through diminished concentration of the sucrose is a n open question. Meihods of Preparing and Polarizing Solutions.I n order to eliminate all errors due to variations in sample, differences in volume of lead precipitate, and similar causes the polarization experiments upon raw sugars and other products were all performed upon the clarified solutions. 130 grams (5 times the normal weight 26 grams) of the sugar, molasses, etc., were dissolved in 370 CC. of cold distilled water. The solution was then clarified with a minimum quantity of anhydrous
lead sub-acetate (Horne's preparation) and filtered. The slight excess of lead in the filtrate was then precipitated with the exact amount of potassium oxalate (avoiding excess) and the turbid solution filtered through kaolin. The first runnings of the filtrate which were usually somewhat milky, were discarded and only the clear bright after-portion used for polarization. In a few instances where lead did not decolorize sufficiently for accurate reading the solution was re-filtered through animal charcoal. Two portions of IOO grams each of the clarified solution (26 grams approximately of substance) were weighed out into IOO cc. (metric) sugar flasks. One of the solutions was made up to volume and polarized in a room heated to 35' C.; the other solution was made up and polarized a t about IZ ' C., the exact temperature depending upon the conditions of the outside weather. The solutions were made up to volume and polarized in a small room 6 feet by 7 feet and 7 feet high, the temperature of which was raised from 2 0 ' C., that of the laboratory, to 35' by means of a small gas stove. The saccharimeter upon which the observations were made was a late model Schmidt & Haensch double quartz wedge compensator, half shade, double field, and mounted upon trestle supports. The accuracy of the instrument had been thoroughly established before using by means of chemically pure sucrose and also by means of quartz plates standardized a t the German Reichsanstalt and a t the U. S. National Bureau of Standards. The quartz wedges and scale of the saccharimeter were enclosed in a case of sheet brass. The temperature of the instrument was taken by means of three thermometers, one placed within the trough of the instrument with the bulb resting within the screw cap before the wedges, one placed a t the side of the instrument with the bulb against the brass wall of the wedge encasement, and one placed in front of the instrument with its bulb inserted in one of the telescope tubes, the eyepiece of the latter having been temporarily removed. When the three thermometers each indicated 3j0, the temperature was controlled a t this point for I to 1% hours before beginning the observations, a t the end of which time i t was assumed that the quartz wedges had acquired the surrounding temperature. The solutions in the flasks were made up to IOO cc. at the same temperature as the instrument and the
572
T H E JOURiVAL OF I.VDUSTRIAL AiVD EAVGINEERING CHELWISTRY.
solutions polarized in zoo mm. tubes. The temperatures of the solutions in the flasks after making u p the volume and in the observation tubes after polarizing were taken as additional checks. The light used for polarizing was supplied by a 32-candle power stereopticon electric incandescent lamp and was filtered through a 3 per cent. solution of potassium bichromate in a 3 cni. cell. The zero point of the instrument was determined before and after each series of observations and the average of the two sets of determinations used as the zero point correction for the series. The determination of the zero point was made by means of the control wedge at IO different points of the scale, the average of the differences between the scale readings of the working and control wedges at these points being taken as the true zero. In determining the zero point a 2 0 0 mm. tube filled with distilled water was always placed in the trough of the instrument in order to secure as nearly as possible the same conditions as in the work of polarization. In making the polarizations ten readings were taken at various positions of the working and control wedges, the difference between the readings being taken a s the polarization. The average of the ten polarizations was then corrected for the zero point as above described and the final result taken as the true polarization of the solution at the temperature of the instrument. The high temperature observations were made late in the afternoon and the low temperature observations early the next morning. The heat of the laboratory was turned off the previous evening and the windows slightly raised. For the low temperature work the temperature of saccharimeter and room according to weather conditions ranged from 8' to 15'. Zero point corrections, making u p of solutions to volume and polarizations were made in the manner previously described. The difference between the polarization a t high and low temperature divided by the difference in temperature gives the variation in the reading of the saccharimeter for each degree C. change. All flasks, tubes, weights, thermometers, etc. used in the experiments had been previously tested as to accuracy, The error of the IOO cc. flasks employed was less than 0 . 0 5 cc. and the error of the zoo mm. tubes less than 0 . I mm. No correction for the slight errors within these limits was introduced into the calculation, as they were smaller
Aug., 1909
than could be measured by the saccharimeter, which could be read only to 0.05 O V. Furthermore, the work was performed upon different products using different flasks and tubes and the conclusions arrived at based upon a general average so that slight errors due to variations in the capacity of the flask or length oi tube or other cause would be largely eliminated. The differences observed in the readings made at different temperatures are simply such as would be noted in the routine work of commercial analysis. Infiuence of Temperature upon tlbe Polarization o f Sugar Cane Molasses.--In the winter of I g o j the writer made a series of observations a t the Louisiana Sugar Experiment Station upon the influence of temperature on the polarization of low-grade Louisiana molasses. The results of this work are given in the following table under Nos. I , 2 , and 3. Sample No. 4 is another product of Louisiana third molasses recently examined by the writer a t The New York Sugar Trade Laboratory.
.5_.
TABLE111 (Influence of TemDerature on the Polarization of Louisiana Molasses.)
1 2 3 4
21.05 16.00 20.55 22.65
31.25 26.89 28.08 32.10
27.53 29.85 32.61 30.38
Ave.
20.06
29.58
30.09
-
-
-
-
-
-
-
10.55 9.13 6.49 6.80
~
20.02 10.65 23.06 11.07 26.46 6.36 24.94 5.72
8.24 23.62
8.47
+0.1075
+0.1122 +0.1172 +0.1113 +0.112
The results show that for the average exhausted Louisiana molasses polarizing zoo V. and containing about 30 per cent. sucrose and 30 per cent. invert sugar, there is a n increase in polarization of 0.112' V. with each degree C. increase in temperature. The effect of temperature upon the polarization of cane molasses is therefore nearly 4 times as great as that upon the polarization of pure sucrose and in the oQfio.de diyectzon. The principal agent affecting the temperature changes in the polarization of cane molasses is not the sucrose, b u t as is well known, the levulose and this change is so pronounced that a method has been worked out by Wiley' for determining the percentage of levulose in sugar mixtures by measuring the difference in polarization at wide intervals of temperature. The effect of temp rature upon the polarization 1
"Principles and Practice of Agricultural Analysis." Vol. 3 p. 267.
BROW-VE O X THE U S E OF TEATIPERAT U R E CORRECTIOA'S. of levulose may be easily calculated from the formula of Jungfle sch and Grimbert [a]', = [101.38 - o.56t + 0.108 (c - IO)]. The specific rotation according to the above formula for the normal weight of pure levulose (c = 26 grams) a t 5' C. would be-100.31~ and a t 30' C. -86.31. The equivalent in degrees of the Ventzke sugar scale for the normal weight of levulose at j oC. would then be (-100.31 x 100) + 66.72 ( [ a ] g sucrose) = -1j0.4' V. and a t 30' C. (-86.31 X 100) + 66.36 ([a]3i0 sucrose) = -130.1' V. The difference in reading of a normal weight of pure levulose (100metric cc. 2 0 0 mm. tube) is therefore 20.3' V. toward the right for z j o C. or 0.812' v. for I O C. increase in temperature. The average exhausted cane molasses of 30 per cent. invert sugar content would contain approximately I j per cent. of levulose. 15 per cent. of 0.812 O V. is 0.12 18' V., the deviation toward the right for I O C.increase due to the levulose of the molasses ; subtracting from this the deviation toward the left for I O C. increase due to the 30 per cent. sucrose of the molasses (30 per cent. of 0.03 = 0.009) we obtained the difference fo.1128, which agrees almost exactly with the average change in polarization for I O c. increase that was obtained experimentally. Determination of the Influence of Temperature upon the Polarization of Raw Cane-Sugars.-It is now possible to calculate the influence of temperature upon any mixture of sucrose crystals and cane mo!asses. Adding together the polarizations and percentages of the ingredients in the sucrose and molasses taken will give the polarization and percentage composition of the resulting raw sugar, and similarly adding together the respective influences of temperature upon the polarization of the sucrose and molasses will show the influence of temperature upon the corresponding raw sugar. A molasses of zo.ooo V. polarization, 3 0 per cent. sucrose, 30 per cent. invert sugar, and fo.112 temperature factor was taken as a basis in the following table. The method of computation may be illustrated by the following example : Polarization. Sucrose (80% of 100) 80.00 Molasses (20% of 20) 4.00 Raw sugar..
.
,
., ...
-
84.00
Sucrose. 80.00 (20% of 30) 6.00
-
86.00
I n the same manner as the above the calculations of Table IV were made upon 2 5 mixtures of sucrose crystals and molasses; the percentages of added
5 73
molasses ranged from 0.0 to 30 per cent. and the polarizations of the mixture from 76 to 100. TABLEIV. (Showing Influence of Temperature upon the Polarization of Calculated Mixtures of Sucrose Crystals and Exhausted Louisiana Molasses ) Temperature factor. Per cent. Invert sucrose Per cent. Polariza- Sucrose. sugar. By formula crystals. molasses. tion. Per cent. Per cent. Actual. 0.0003P. 0.00 -0.0300 -0.0300 100.00 0.00 100.00 100.00 99.12 0.38 -0 .0282 -0,0297 1.25 99.00 98.75 0.75 -0.0265 -0 ,0294 2.50 98.00 98.25 97.50 1.13 -0.0247 -0.0291 3.75 97.00 97.37 96.25 1.50 -0,0229 -0.0288 95 .OO 96.00 96.50 5 .oo 1.88 -0.0212 -0.0285 95 .OO 95.62 93.75 6.25 2.25 -0,0194 -0.0282 94.75 92 .50 7 .50 94.00 2.63 -0.0176 -0.0279 91.25 8.75 93 .OO 93.87 3.00 -0.0158 -0.0276 10.00 92.00 93 .OO 90.00 3.38 -0.0141 -0,0273 92.12 11.25 91 .OO 88.75 3.75 -0.0123 -0,0270 12.50 90.00 91.25 87.50 4.13 -0.0105 -0.0267 86.25 13.75 89.00 90.37 4.50 -0.0087 -0.0264 85 .oo 15 .OO 89 .50 88.00 4.88 -0.0070 -0,0261 83.75 16.25 87 .OO 88.62 5.25 -0.0052 -0.0258 87.75 82 .50 17 .50 86.00 -0.0255 5.63 -0.0034 86.87 81.25 18.75 85 .oo 6.00 -0.0016 -0.0252 86.00 20 .oo 84.00 80.00 6.38 +0.0002 -0.0249 85.12 83.00 21.25 78.75 6.75 +0.0020 -0,0246 84.25 77.50 22 .50 82 .oo 7.13 +0.0038 -0.0243 83.37 23.75 81 .oo 76.25 7 .50 f0.0055 -0.0240 75 .OO 25 .oo 80.00 82 s o 7.77 79.00 81.62 73.75 26.25 0.0073 -0.0237 8.25 f0.0091 -0.0234 78 .OO 80.75 72 .SO 27.50 8.63 +0.0108 -0,0231 28.75 71.25 77.00 79.87 9.00 f0.0126 -0.0228 30.00 76,OO 79 .OO 70.00 c _ _ -
--.
+
The temperature factors of the above table can be verified by making the calculations upon the percentage of levulose, in the manner previously described. Example : For an 84 test sugar of the table there would be the following : Temperature factor for 86% sucrose (86 X -0.0003) = -0.0258 " " 3y0 levitlose (3 X +0.00812) = +0.0244 ('
''
84 test sugar
=
- 0.0014
which is in very close agreement with the result of the table - 0 . 0 0 1 6 . I t will be noted from the results of the above table t h a t for very high-grade sugars the temperature factor calculated for the mixtures of sugar crystals and molasses and that calculated b y the formula 0.0003P are in very close agreement. The percentage of levulose in the raw sugar is too small to affect appreciably the temperature factor of the sucrose. As the polarization falls below 96-97 Invert sugar. 0.00
(20% of 30)
6.00
6.00
Temperature factor. (80 X -0.00030) -0.0240 (20 X +0.00112) +0.0224
__-
-0.0016
and the percentage of levulose increases, the effect of the temperature upon the rotation of the latter begins to lower appreciably the sucrose factor until
5 74
T H E JOURLVAI, OF I N D U S T R I A L AiVD ENGIA'EERING CHE;MISTRY.
a t a point about 83' V. the two influences-that of the temperature upon the levulose and other impurities and t h a t of the temperature upon the sucrose and quartz wedges of the instrument-exactly counterbalance one another. Two chemiFts polarizing such a sugar, one working a t 30' C. and one working a t 20' C., other conditions being equal, would obtain perfectly concordant and correct readings ; the application of the theoretical sucrose correction would place the observation of the chemist working at 30° C. 0.25' V. too high, Below 83' the effect of temperature is seen to increase rather than diminish the reading. The levulose correction more than counterbalances the sucrose factor. Every chemist knows how pronounced this influence of temperature upon the levulose is in the polarizations of syrups and molasses, how the simple handling of the observation tubes will increase the reading. The same influence is manifested with low-grade cane-sugars only to a less degree. When such sugars are polarized above zoo C. a correction would have to be subtracted to secure the reading that would be obtained under standard conditions. To add a correction, as required by the IT. S. Treasury Department Regulations, would manifestly only further increase the errors of observation. The results of Table IV were calculated for mixtures of sucrose crystals and Louisiana molasses. Variations in the composition of the molasses, according to locality and methods of manufacture, will necessarily affect the temperature factor of the sugar. The results upon many grades of commercial sugars from different countries given in the succeeding tables agree, however, on the whole very closely with those calculated upon the basis of Louisiana niolasses. In the following table polarizations and analyses are given of various commercial sugars testing over 96. The temperature factor (change in polarization for I ' C. increase in temperature) of each sugar in this and succeeding tables was determined b y the method previous'y described. The temperature factor as calculated from the polarization (P) b y the expression o.o003P, is also added for purpose of comparison. The temperature factor observed for such sugars as polarize over 96 is seen to agree very closely with that calculated from the formula and the application of the latter as a correction in the polarization of such grades of raw sugar would unquestionably increase the accuracy of the observation.
Aug., 1909
TABLEV. (Showing Influence of Temperature upon the Polarization of Commercial Sugars Testing over 96' V.) Temperature factor (change per 1 ' C. increase).
8
3! c ........ . . 9 8 . 5 5 .......... 9 7 . 8 5 ......... 9 7 . 9 5
1 Java . 2 " 3 Peru 4 5 Cuba.. . 6 Brazil . 7 Louisiana 8 San1)omingo.. 9 " " ..
96.55 96.40 96.25 9h.15
0.64 0.82 1.29 0.52 0.78 1.98 1.99 1.02 1.53
0.19 0.23 0.43 0.45 1.03 0.64 0.93 1.54 0.85
0.21 0.52 0.29 0.46 0.31 0.25 0.70 0.77 0.48
-0.03 1 1 -0.0268 -0,0315 4.0301 -0,0276 -0.0291 4.0277 -0,0313 -0,0230
-0.0296 -0 ,0294 -0.0294 -0.0292 4.0291 4,0290 -0.0289 4.0289 -0,0288
Average ........ 9 7 . 1 4
1.17
0.70
0.44
-0.0287
4.0291
...... .... 9 7 . 4 5 .. ... . . 9 7 . 1 5
'I
... . . . . . . .....
----
The average temperature factor of -0.0287 is a little higher than that calculated for a 97 test sugar in Table IV, niz.) -0 0247. The difference can be attributed to the diminished ratio of levulose to dextrose in the reducing sugars of the juice of more matured cane of tropical countries as compared with that of Louisiana molasses. I n Table VI polarizations, analyses and temperature factors are given for various commercial sugars testing between 90 and 95. TABLE VI (Showing Influence of Temperature upnn the Polarization of Commercial Sugars Testing between 90 and 95' V.) Temperature factor (change per 1 O C. increase).
10 11 12 13 14 15
. .. ... . '( .. . . . . . . Louisiana.. . . . Cuba ..... . . . . Cuba.. "
92.57 92.30 91.75 91.45
1.83 2.29 3.36 2.68 2.12 3.97
-
.
94.50
........ 93.75
Philippines
..
Average.. . . . . ,
.
_
92.72
_
2.71
1.97 1.83 1.32 1.11 2.00 2.11 _
1.72
0 . 6 3 -0,0212 0 . 5 5 -0,0160 0 . 4 3 -0,0077 2 . 6 5 -0.0240 3 . 2 8 -0,0244 1 . 2 7 -0.0074
~
-
1.47
-0,0168
-0,0287 -0,0281 -0,0278 -0.0277 -0.0275 -0.02 74
_
-0,0278
The temperature factor for the sugars in the above table is seen to be very variable; where the percentage of invert sugar is high as in Nos. IZ and 15 the temperature factor is much lower than in sugars of equal polarization, b u t lower invert sugar content. The temperature factor calculated by the formula 0.0003P is very much too high. The average of the results for invert sugar and temperature factor for the sugars in Table VI agrees
_
BROWNE O N T H E C'SE OF T E d I P E R A T C R E CORRECTIONS. almost exactly with that calculated for 92.7 test sugar in Table IV. In Table VI1 results are reported upon ten sugars testing between 85 and go. TABLEVII. (Showing Influence of Temperature upon the Polarization of Comm e r a a l Sugars Testing between 85 and 90' V.) Temperature factor (change per 1 C. increase).
---
5 75
tions from the sucrose and levulose percentages, in the manner described under Table VII, a temperature factor is found of -0.025 for the sucrose and +0.023 for the levulose and for the combined influence of the two -o.ooz which is practically identical with the temperature factor found. TABLEV I I I . (Showing Influence of Temperature upon the Polarization of Commercial Sugars Testing between 80 and 85' V.) Temperature factor (change per l o C. increase),
----
NO. 16 Cuba.. , . . , 89.50 17 Philippines.. 89.20 18 Brazil (Muscovado).. 88.90 19 WestIndies 88.50 20 L o u i s i a n a . . . 87.60 21 Cuba.. . 87.20 22 Cuba . . . , , 87.00 23 Brazil (Muscovado). , .56.80 24 S. American (Muscovado).. 86.70 25 Brazil (Muscovado) 86.15
. .. .
2.05 4.63
3.54 2.11
1.13 -0,0139 1.27 --0.0110
.. . ... ... . . ..
4.46 4.77 4.67 4.24 2.11
5.40 5.44 2.30 3.55 2.42
0.86 1.03 3.17 4.93 1.49
Average
....
4.46
5.61
1.15
4,0269 -0.0268
4 , 0 0 2 3 -0,0267 -0.0077 -0.0266 -0.0106 -0.0263 -0.0094 -0.0262 -0.0180 -0.0261 -0.0143
-4.0260
1.49
-0.0156
-0.0260
4.46 5 . 1 9 1 . 2 5 ---
-0.0162
-0.0258
87.76
-0.0
4.81
4.07
4.65
4.02
1.78
1 19 -0.0263
It will be noted that the temperature factor observed for raw cane-sugars polarizing between 86 and go is less than half that calculated by the formula. The average factor - - - o . o I I ~for a n 87.76 test sugar is somewhat higher than that indicated by Table IV. The difference is explained by the fact that the sugars of Table VI1 average about 0.5 per cent. less invert sugar than the sugars of same polarization in Table IV. By calculating the temperature factor of the above average froni the percentage of levulose, however, the same result is obtained. Letting the sucrose = P 113 per cent. of invert sugar, the average per cent. of sucrose = 89.12.
+
Sucrose factor = 89.12 X -0.0003 Levulose = 2.04 X +0.00812
= -0.0267 = +0.0166
Calculated temperature factor Observed
= 4.0119
26 27 28 29 30 31
.....
-0.0115 Cuba . . . . . 84.70 3 . 6 9 4.26 2.63 Philippine (Mats). . . . . , . . 8 4 . 1 0 7 . 3 8 ( 3 . 4 9 1 . 8 5 1 -0.0021 Philippine I (Mats).., , . , 82.55 7.31 { 3 . 4 9 1 . 8 5 } -0.0031
.. . . ..
Philippine (Mats)... , 82.40 7 . 4 5 Cuba . . . . . . . . . . 82.05 3 . 2 1 81.00 5 . 4 5 Cuba
.._.......
Average..
...
I I
I
[ 3.49 1 .85 J
-0.0252 4.0248
4.05 3.57 4 . 8 5 2.77
0.0000 -0.0247 -0,0145 -0,0246 -0,0039 -0.0243
3.94 2.42
-0,0051
---82 .SO 5.75
-0,0254
~
_
-0
0248
It will be noted that for such sugars as the above the temperature factor is practically 0 ; for a n average sugar of this class the same polarization would be obtained a t 30' C. as a t 20' C. The application of the correction 0.0003P would result in the addition of 0.25' V. to the polarization obtained at 30'. I n Table I X results are reported upon several sugars which tested less than 80' V. TABLEI X . (Showing Influence of Temperature upon the Polarization of Commercial Sugars Testing under 80'V.) Temperature factor (change per 1 O C. increase).
= --0.0101
I n Table VI11 results are reported upon 6 sugars testing between 80 and 85. The temperature factor of the following sugars is seen to average only 1/5 that calculated by the polarization formula. The average factor -0.005 for a sugar testing 82.8 is slightly above that indicated by the table (+o.ooj). This difference as in the previous example is due to the lower content of invert sugar. By making the calcula-
. 79.65 . . 78.60 . . . 78.55 ... . . 67.70 - -
32 Lonisiana.. . 33 Cuba. ... . . 34 Cuba.. _ .. 35 Cuba.. . Average
....
76.18
6.80 4.21 4.53 11.18
4.84 5.05 4.80 6.70
4.21 2.70 2.83 3.75
6.68
5.35
3.37
-
-
~
_
f0.0068 -0.0045 -0.0105 f0.0286
-0.0239 -0,0236 -0,0236 -0.0203
f0.0051
-0.0228
_
_
The temperature factor of all low-grade canesugars will necessarily vary considerably, owing to fluctuations in percentages of invert sugar and moisture. The average factor for the four sugars in Table I X shows a n increase in polarization of
_
THE JOURiVAL OF INDUSTRIAL- A N D E.VGINEERI.VG
5 76
V. for I O C. increase for a sugar testing about 7 6 . This varies a little from the value indicated in Table IV, but by making the calculations from the content of levulose and sucrose in the manner previously described we obtain a factor of fo.0270 for the levulose and -0.0235 for the sucrose and for the combined influence of the two a factor of +o.0035, which is in close agreement with the temperature factor found. The temperature factor calculated by the formula 0.0003P shows a decrease of -0.0228 for each degree C. increase. I n other words the polarization formula would add a correction of 0.23' V. to a cane-sugar testing 76 at 30' C., whereas in reality a correction of 0.05 should be subtracted from the reading in order to obtain the true polarization a t 0.00j O
zoo
c.
It should be remarked in passing that the errors involved in the application of sucrose temperature
CHE41.11.5TRY.
Aug., 1909
cane-sugars have an additional significance in view of the fact that the lowest grades of sugar arrive for the most part a t the ports of the United States in the warmest months of the year when the correction errors would be the greatest. This can be seen best from a n inspection of Table X which gives the monthly distribution by grade of the raw sugars analyzed at the New York Sugar Trade Laboratory for 1908. The results are expressed in percentages of the total number of samples analyzed for the year. It will be noted that the maxima of the highest grade sugars occur in the cool months and the maxima of the lowest grade in the warm months, there being a progressive lowering of the quality of sugar as the warm weather of summer advances. The temperature of a laboratory in the climate of New York need rarely exceed 2 0 ' C. from October until May, and in this period of 7 months
TABLEX. DISTRIBUTION O F SUGARS BY GRADE FOR EACH MONTH OF 1908 Polarized at The New York Sugar Trade Laboratory. (InPercentage of Total Number for the Year.) Polarization. Jan. Feb. March. April. May. Oct. July. Aug. Sept. Nov. Dec. Total. June. Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. 97-100 96- 97 95- 96 94- 95 90- 94 85- 90 70- 85
0.37 0.76 1 .OO 0.34 0.62 0.06 0.03
0.59 2.54 5.22 2.07 0.47 0.02 0.02
0.15 3.16 5.96 2.46 0.72 0.36 0.03
0.38 2.47 6.64 2.84 0.60 0.42 0.20
0.37 1.44 3.47 3.30 1.87 1.41 0.33
0.15 0.89 2.35 1.27 1.29 2.19 0.27
0.75 0.89 1.49 1.39 1.47 1.31 0.46
0.64 0.47 0.99 0.79 0.58 1.23 0.84
3.18
L0.93
12.84
13.55
12.19
8.41
7.71
95 .OO Mean temD.C".. 2 0 . 3 7 Maxtemp. C'.. 2 1 . 5 Min. temp.Co.. 1 8 . 5
95.52 20.50 21.0 20.0
95.21 20.42 21.0 20.0
95.04 20.46 22.0 19.0
93.81 22.14 27.0 20.0
92.78 25.68 29.0 23.0
93.21 27.93 31.0 26.0
. .. Mean polar . . . Total.. ,
,
3.28 0.43 0.73 0.63 0.30 0.95 0.45
5.55 0.09 0.36 0.35 0.89 0.13 0.11
0.58 0.14 0.21 0.26 0.33
5.54
6.77
7.48
91.59 25.38 30.0 20.0
94.28 22.38 24.50 20.0
97.13 20.22 22.0 18.0
__
4.41
2.75 0.82 0.55 0.08 0.13 0.14 0.00
19.39 14.96 29.34 15.66 9.10 8.48 3.07
6.93
4.47
100.00
96.87 20.59 21.5 19.0
96.55 20.25 21.5 19.5
1
.oo
-__ ,
. , ..,
. . . . .. ..
...... ......
Total samples analyzed for 1908, 9,215. Average of all polarizations for 1908, 94.68.
corrections to the polarization of raw cane-sugars may be still further intensified if the correction is made by means of the U. S. Treasury Department table of sucrose values, when quartz plates are used which test higher than the sugar under examination. It is wrong in principle to apply the correction for a 100' V. quartz plate, for example, to a sucrose solution testing 50' V., yet the writer has known of chemists applying the correction for the sucrose value of 100' V. quartz plates to the polarization of raw sugars, syrups, molasses, and all other products which were examined upon the saccharimeter. Conditions Underlying the A pplicatioic of Temperature Corrections to the Polarization of Raw CaneSugars.-The errors involved in the application of the U. S. Treasury Department method of temperature corrections to the polarization of raw
60 per cent. of all the raw sugars polarized were received. The remaining 40 per cent. of sugars arrived in the summer months when the average laboratory temperature exceeded considerably 20' C. and polarization under standard conditions is not possible without artificial refrigeration. The application of the formula PzO= P'[I +0.0003 (t - 2 0 ) ] would be approximately correct, as we have seen, with sugars polarizing over 96, which for the warm months make up about 9 per cent. of the total. The above formula would also hold partially for the large class of centrifugals polarizing between 95 and 96 which for the warm period make up also about 9 per cent. of the total. For the sugars testing under 95, over 2 2 per cent. of the year's total for the warm months, the formula gives a polariza-
BROWNE ON T H E C S E O F TEMPER.4 T C'RE CORRECTIOSS. tion considerably in excess of the true reading a t zoo, the error amounting to over 0.3' V . on very warm days with low-grade Cuban and Philippine sugars. The same error would extend of course to sugars polarized in the cool months of the year in case of laboratories heated above 20' C.-the general condition in the United States. Table X I , which is based upon the average of the various results previously presented, gives the approximate composition of raw cane sugars and the change in the polarization of the same for each degree C. increase in temperature. The results agree closely with those of Table IV upon the theoretical mixtures of sucrose crystals and molasses; the small differences are due to the slightly lower content of invert sugar (and hence of levulose) in the average raw cane-sugar than in those calculated upon the basis of Louisiana molasses.
577
PZo= P' + 0.0015 (I" 80) ( t o - 20). The correction in polarization for I O C. increase in temperature for the average raw cane-sugar is also shown graphically in the diagram. The correction by the formula 0.0003P is also given for comparison.
TABLE XI (Showing Approximate Composition of Rarr Cane Sugars and Variation in Polarization for 1 ' C. Increase in Temperature.) Variation in polarization for 1 C. increase. , _ A -
Polarization.
100.00 100.00 0.00 99.10 0.35 99.00 98.00 98.20 0.70 97.00 97.30 1.05 96.00 96.40 1.40 95.50 1.75 95.00 94.00 94.60 2.10 93.70 2.45 93.00 92.00 92.80 2.80 91.00 91.90 3.15 91.00 3.50 90.00 90.10 3.85 89.00 88.00 89.20 4.20 87.00 88.30 4.55 86.00 87.40 4.90 86.50 5.25 85.00 85.60 5.60 84.00 83.00 84.70 5.95 82.00 83.80 6.30 81.00 82.90 6.65 82.00 7.00 80.00 81.10 7.35 79.00 80.20 7.70 78.00 79.30 8.05 77.00 76.00 78.40 8.40 75.00 75.50 8.75
0.00 0.00 0.00 -0,0300
0.15 0.30 0.45 0.60 0.75 0.90 1.05 1.20 1.35 1.50 1.65 1.80 1.95 2.10 2.25 2.40 2.55 2.70 2.85 3.00 3.15 3.30 3.45 3.60 3.75
0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.25 3.50 3.75 4.00 4.25 4.50 4.75 5.00 5.25 5.50 5.75 6.00 6.25
0.15 0.30 0.45 0.60 0.75 0.90 1.05 1.20 1.35 1.50 1.65 1.80 1.95 2.10 2.25 2.40 2.55 2.70 2.85 3.00 3.15 3.30 3.45 3.60 3.75
-0.0285 -0.0270 -0.0255 -0.0240 -0.0225 -0.0210 -0,0195 -0.0180 4.0165 -0.0150 -0.0135 -0.0120 -0.0105 -0.0090
-0,0075 -0.0060 -0.0045 -0.0030 --0.0015 0.0000
+0.0015 +0.0030 C0.0045 0.0060 +0.0075
+
-0.0300 -0.0297 -0.0294 -0,0291 -0.0288 -0,0285 -0.0282 -0.0279 -0.02 76 -0,0273 -0,0270 -0,0267 4.0264 -0.0261 -0.0258 -0.0255 -0.0252 -0.0249 -0.0246 -0,0243 -0.0240 -0.0237 -0.0234 -0.023 1 -0,0228 -0.0225
The approximate corrections necessary to be applied to the polarization of raw cane-sugars for I O C. increase are of course obtained by simply reversing the algebraic signs of the values in Table X I . The following general formula for correcting the polarization (P) a t t o of any raw cane-sugar to PZo0is calculated from the values of Table X I ;
The Efect of Temperature upon the Polarizatton o j Beet Products.-In connection with the results obtained upon sugar-cane products it was thought well to make a few comparisons regarding the effect of temperature upon the polarization of similar materials derived from the sugar beet. The latter differ in composition in several important respects from products of the sugar-cane. In distinction from the latter beet molasses and raw beet sugar contain but small amounts of reducing sugars and a much higher percentage of nitrogenous substances. Beet products are also usually characterized by the presence of the sugar raffinose in small amount. The polarization of beet products agrees more closely with the true sucrose content than is the case with cane products. The application of the temperature correction for sucrose to the polarization of raw beet sugars would therefore seem upon theoretical grounds less open to objection than with raw cane-sugar. It was thought advisable, as in the case of raw cane-sugars, to study first the effect of temperature upon the polarization of exhausted beet molasses and then calculate what the effect would be upon mixtures of this molasses and sucrose crystals as was done in the case of cane molasses.
THE JOURAVAL O F IAVPIJ’STRIALA N D EiVGI,VEERISG CHEiMISTRY.
578
Influence of Temperature upon the Polarization 0 ) Sugar Beet Molasses.--For the purpose of this work three samples of molasses from various American beet sugar factories, kindly supplied by the
Aug., 1909
same manner as described under cane molasses. The application of the correction formula is thus seen to give results which are b u t little higher than would be actually obtained. This conclusion was
TABLE XII. (Showing Composition of Beet Molasses and Influence of Temperature upon Polarization.) Polarization. 7
No.
Direct.
1 2 3
49.80 50.00 53.87
-16.50 -13.62 -12.24
Av .... 51.22
-14.12
-
Invert
Sucrose b y Clerget.
Sucrose. Per cent.
Raffinose. Per cent.
50.18 48.43 50.04
50.07 46.79 47.53
1.74 3.41
....
0.00 0.10 0.20 0.30
N. Bases, gums, etc. Per cent.
Change in polarization, 1 C. increase,
0.64 0.65 1.53
8.99 7.97 5.89
17 .OO 20.03 22,54
-
23.30 22.82 19.10
__
0 .oooo -0.0113 -0.0045
19.86
21.74
-0.0053
-
-
-
48.13
1.72
0.94
TABLE XIII.
100.00 1 0 0 . 0 0 9 5 . 0 0 94.80 90.00 89.60 8 5 . 0 0 84.40
Water. Per cent.
49.55
(Showing Influence of Temperature upon the Polarization of Calculated Mixtures of Sucrose Crystals and Exhausted Beet Molasses ) Temperature factor.
0.00 10.00 20.00 30.00
Ash. Per cent.
__
Bureau of Chemistry, Washington, D. C., were examined in accordance with the method previously described. The results of the work are shown in Table X I I . The increase in direct polarization over the sucrose by Clerget in two of the samples would indicate a n appreciable amount of raffinose. The percentages of sucrose and raffinose were calculated by Creydt’s formula. The average composition of the above molasses agrees closely with that of European beet sugar factories. The effect of temperature upon the polarization of beet molasses is seen to be almost negligible, there being a decrease of only 0 . 0 0 5 3 ~Ti. for each degree C. increase in temperature. The calculated value for the sucrose of the average beet molasses would be ---o.o144 and for the levulose $0.0041, leaving a difference of ---o.orog, which is about double the value found experimentally. The effect of temperature upon the polarization of raffinose and the other constituents of beet molasses was not investigated.
100.00 90.00 80.00 70.00
Invert sugar. Per cent.
0.00 0.15 0.30 0.45
-0,0300 -0.0275 -0,0250 -0,0225
-0.0300 -0,0285 -0.0270 -0,0255
Determination of the Influence of Temperature upon the Polayization of Raw Beet .Sugars.-The calculation of the influence of temperature upon the polarization of mixtures of sucrose crystals and beet molasses is indicated by a few examples in Table XIII. The calculation was made in the
~
7.62
verified by determination of the temperature factor upon 5 raw domestic beet sugars. TABLEXIV. (Showing the Influence of Temperature upon the Polarization of Raw Beet Sugars.) Temperature factor (change per 1 C. increase).
No.
Polarization 200 c.
1 2 3 4 5
Average.
Found.
7
B y formula 0.0003P.
93 20 91.25 89.00 86.60 85.50
-0.0220 -0.0276 -0.0205 -0.0263 -0,0214
-0.0280 4.0274 -0,0267 4,0260 4.0257
89.11
-0.0236
-0.0267
.....
_--A_____
The above temperature factor found for an average beet sugar of 89 polarization agrees closely with that calculated in Table XIII. We are therefore probably safe in saying that the application of the formula PZo0= P‘[I +0.0003 ( t - 2 0 ) ] to the polarization of raw beet sugars will give very closely the polarization that would be obtained under standard conditions. This of course would not hold for such beet sugars as contained much reducing sugar. CONCLUSIOK.
I t has been shown in the foregoing pages (I) from the theoretical consideration of the effect of temperature upon the specific rotation of sucrose and levulose, (2) from a consideration of the effect of temperature upon the polarization of mixtures of sucrose and sugar-cane molasses, and (3) by actual experiment that no temperature correction established for the changes in specific rotation of sucrose can be applied successfully to the polarization of raw cane products. A question which still remains to be considered is whether any kind of temperature correction can be adopted that will give the polariscope reading obtainable under standard conditions. The first method which suggests itself for this purpose is a diminishing scale of corrections such
j82
T H E JOURNAL OF I N D U S T R I A L A-VD ENGI-VEERING CNEML5TRY.
I n the case of boiled meats, the percentage increase amounted to 20.9 for the 85OC. and 12.1 for the i o o 0 C . sample, and for the roasted meats j . 4 per cent. in the case of the gas-cooked and 13.9 per cent. in the Aladdin-cooked sample. The next most striking difference to be brought out is shown in the percentage of coagulable nitrogen and protein. The samples for the two boiled and the gas-roasted meats obtained from the 43day stored samples are utterly absent of this constituent. The Aladdin-roasted meats, however,
Description of sample., ,
..
sample, varying with a difference of 1.96 per cent. in the meat boiled at 85' C. to only 0.19 per cent. in I O O O C . boiled meat. The variation in moisture content accounts for this wide range as will be shown subsequently. The total organic extractives were higher in every case in the meats kept for the longer period, being in per cent. of their total amounts 20.5, 30.0, 1 1 . 2 , and 1 0 . 7 , respectively, for the meats boiled a t 85' and 100' C., and those roasted at 195' and I O O O C . The total soluble nitrogen was higher in the samples which
TABLEI. CHEMICALCOMPOSITIONOF COLDSTORAGEFLESH. LEAN BEEF LOIN, COOXED. (Calculated to the Fresh Substance.) Boiled a t 100°C. Roasted a t 195' C. , ., . , . , Boiled at 85' C. 3 hours. 3 hours. 1 hour.
.. .
....
---..--
Roasted a t 100' C.
1990 43 P. ct.
1987 6 P. C t .
1991 43 P. ct.
lsis hrs. 1979 6 P. ct.
2 l i ~111s.
1968-77 6 P. Ct.
P. ct.
1989 43 P. ct.
61.60
63.03
61.66
59.53
63.66
64,95
65.68
65.55
3 .05
3.56 33.43 34.99
2.84 35.87 38.71
3.18 37.60 40.78
4.37 32.52 36.89
4.42 31.06 35,48
4.27 30.50 34.77
4.63 30.38 3 5 . 01
0.09 0.16 0.25 25.37 25.62
;Cone 0.30
0.14 0.44
0.58
23.36 23.46
26.33
None 0.34 0.34 26.38 26.72
0.16 0.18 0.34 23.19 23,53
None 0.41 0.41 21.73 22,14
0.49 0.12 0.61 21.46 22.07
0.53 0.25
0.30
. . . . . 1.20 ............................ 2.10 . .. . . .. . . . 1 0 . 1 4
1.08 1.45 2.53 9.85
0.75 0.92 1.67 9.32
0 99 1.18
1.23 1.74 2,77 92 2
1.22 1.86 3.08 9.12
1.11
1.59 2.70 8.95
1.26 1.73 2.99 9.25
0.71 0.19 0.90
0.73 0.22 0.95
0.60 0.22 0.82
0 67
1.06 0.11 1.17
0.93 0.21 1.14
0.96 0.09 1.05
0.86 0.23 1.09
0.014 0.027 0.041 0.287 0.328 4.059 4.387
None 0.048 0.048 0.346 0,394 3.738 4,132
0.022 0.071 0,093 0.238 4.214 4.545
Sone 0.055 0,055 0.316 0.37I 4.220 4.591
0.026 0.028 0.054 0.395 0.449 3.710
Sone 0.066 0.066 0.391 0.457 3.476 3.933
0.078 0.019 0.097 0.355 0.452 3.434 3.886
0.084 0.040 0.124 0.404 0.528 3.345 3,873
0.093 0.031 0.124 0.073 0 . I97
0.120 0.026 0.146 0.093 0.239
0.127 0.054
0.145 0.045 0.190 0.065 0.255
0.129 0.047 0.176 0.060 0.236
0.142 0.044
0.217
0.128 0.025 0.153 0.092 0.245
. .... . . .. .. . . .. . . . . . .. . . .
., , .. , . .. . Water.. . , . . . , , Dry substance: , Soluble. , , , . . , . . . , , , Insoluble. . . . . . . . . . . . . .
Protein: Soluble coagulable. . , . . , , . , . . . , . . . . . Soluble non-coagulable.. Total. , . . , . . . .
.
. ... . .
.....................
1966-67
Aug., 1909
26.91
1992 43
P. C t .
0.78 20.90 21.68
Organic extractives:
.
Non-nitrogenous . . , . . . . Total F a t . , . . , . , . , . , , . . .. , . , , . .. -4sh: So1ub 1e . , . , . , , . . . . . . . . . I ...........
.,.........
Nitrogen: As soluble coagulable protein. . . . . . . . As soluble non-coagulable protein . Total ............................ As soluble non-protein substance.. . . Total. . , . Insoluble. . . , . , . . . Total. . . . . . . . . , . Phosphorus : Soluble inorganic. . . , . ... Soluble organic., . . . . . .. . Total. . . . . . Insoluble.. . . . , . . . . Total
.. .
.
. . . . ............ . . ... . . .. . . . . .. . . . . . 0 . 0 9 6 . .. .. . . . . . . 0 . 0 4 8 .. .. . . . . . . . . . . . . . 0.144 0.073 . . . .. .. . .
............................
showed a percentage of this constituent which was even a little higher than the samples from the 6-day storage meats. This difference may have been due either to the more moderate temperature of cooking or to the fact that the sample from the 43-day cold storage meat was kept in the oven 30 minutes longer, in order to allow the inner temperature to reach the same point as that of the corresponding sample from the 6day cold storage meat. The total protein showed throughout a tendency to be lower in the 43-day
0.331
2.17 11.01
0.21 o 88
4.159
0.181
0.074 0.255
0.186 0.051 0.237
were gotten from the 43-day stored meat, showing respectively an increase, calculated in per cent. of the total gain, of 20.1, 1 2 . I , 1.8, and 16.8 for the boiled and roasted meats. Concerning the different forms of phosphorus, the soluble inorganic was distinctly higher throughout, showing a gain of 33.3 per cent. for the 85OC. boiled, 29.0 per cent. for the roooC. boiled, 14.1 per cent. for the r 9 j ° C . roasted, and 10.0 per cent. for the rooo C. roasted meat. The organic phosphorus showed a tendency to be lower in the meat cooked
E M M E T T AATD GRINDLEY OA\- C H E M I S T R Y OF FLESH. cooked cold storage samples, that is, the cold water extraction and the subsequent separation of the various constituents was undertaken. I n the case of the broths from the boiled meats, the same soluble constituents were determined in the clear filtrates as were estimated in the cold water extracts of the uncooked and cooked meats. The residues left upon the filter were analyzed for the insoluble protein and the fat. The data thus obtained, as regards the various constituents, were directly comparable with those from the cooked meat and gave a means of determining the nature of the loss of these several constituents. The drippings from the roasted meats were thoroughly extracted with hot water, and the extracts were measured, filtered, and analyzed in exactly the same manner as the broths. I n this way the soluble and insoluble portions were separated and the analysis was thus obtained upon a basis similar to that of the corresponding cooked meats. The total losses resulting from the cooking of the samples were ascertained by transferring the meats, while still warm, to tared glass covered jars, After allowing several hours for the samples to cool in the refrigerator, they were weighed and the losses calculated. By this means of cooling the meats, the usual continued loss of moisture after removal of the hot cooked product was reduced to a' minimum. I t should be stated a g a h in connection with the chemical analysis, that a t the time of making this preliminary study upon cold storage flesh, the methods of determining creatin,' ammonia,' and total acidity were not sufficiently developed for use. DISCUSSIOS.
The data relating to the results obtained from the cooking tests are given for the meats, in Table I (calculated to the fresh substance), in I1 (calculated to the fat-free substance), and in I11 (calcuIated to the same water content as the corresponding samples held in storage for the shorter period), and for the broths and drippings in Table IV (calculated in per cent. of the uncooked meats), and in V (calculated in respect to the proportional distribution of the several constituents), CHEMICAL COMPOSITION OF THE COOKED MEATS.
In referring to the data for the meats, it will be"'seen _. in the case of the boiled samples, which
* Grindley and Woods, J , Raol. Chew., '2. Jbid., S. 2 Gill and Grindley, Science, 27.
Emmett and Grindley,
58 1
were held in storage for 6 days, that the results are reported as the average of two tests. For example, in the sample cooked a t 85' C., the data represent the average of laboratory numbers 1966 and 1967. The object of carrying out the duplicate tests in these two cases was to ascertain just what might be our criterion as to the actual influence of cold storage, whether the differences which might appear to be due to refrigeration were not really a resultant of the errors arising from the method of cooking. A study of these data showed, when calculated upon the fresh basis, that the duplicate samples did not correspond very well in several of their percentage constituents. This was most marked, perhaps, in the case of the water, where samples 1966 and 1967 were respectively 61.95 and 6 1 . 2 4 per cent., and samples 1968 and 1977'were each 60.96 and 62.35 per cent., making a difference in the former case of 0.71 per cent. and in the latter of I,39 per cent. These dissimilarities in the moisture content of the cooked meats are not a t all surprising, especially in the case of boiled meats. However, in following out the same general plan of calculating these data as was done for the uncooked meats, namely to the fat-free basis and then to the same water content it was found, in each case, that the respective tests agreed quite well. It is obvious from the above statements that it will be best, in our detailed study of the influence of cold storage, to consider the data relating to the cooked meats, in these several cooking experiments, as calculated from the fat-free substance and then to the same water content as the meats held in storage for the shorter period. However, a brief survey of the results as calculated to the fresh substance, Table I, will be of interest in bringing out certain facts which do not seem to have been influenced in the main by either the moisture or the fat content.
Chemical Composifion of Cooked Beef Loin, Calcu lated upon the Fresh Basis. The percentage of soluble dry substance was found to be higher throughout for the samples which had been kept in storage 4 3 days, but in the case of the roast (195' C . ) , the difference was so slight as to be neglible, However, if allowance was made for the soluble ash, the resulting soluble organic matter was found to be greater in all the cooked samples which were kept for 4 3 days.
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
