106
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 .
the evolution of gas begins both sooner and with a much greater degree of regularity than if meal is used and set a t the most favorable temperature. CONCLUSIONS.
Feb., 1912
of fermentation t o which it is subjected. This difference in the losses of materials in the preparation of the two kinds of bread is t o be explained b y the fact that ( I ) there is no alcohol found in the former; (2) t h a t owing t o inherent difference in the nature of the ferments involved it is subjected t o far less fermentation; and ( 3 ) the gases are much lighter. The author wishes t o express his gratitude t o Robert Kennedy Duncan for his helpful advice and direction in this work.
The leaven in salt-rising bread is not yeast a s is indicated b y the literature on the subject, b u t certain bacteria. These bacteria aerate the bread b y decomposing certain of its constituents, principally the sugars, into gaseous products and not, as has been suggested, b y producing acids which liberate carbon dioxide LABORATORY O F INDUSTRIAL RESEARCH, from the soda. The microbic flora involved varies UNIVERSITY OF KANSAS. greatly, depending upon the temperature to which -----the meal is subjected in’ setting the “batter.” The organisms t h a t predominate in the batter when i t is A STUDY OF THE VISCOSITY OF FISH OILS. made b y stirring the meal into boiling milk or water By GEORGE F. WHITE. are only occasionally found upon plates made from Received November 8 . 191 1 . batters that were not subjected t o temperatures Up t o the present, the measurement of the viswhich destroy non-spore-bearing organisms. The chief cosity of oils has been carried out b y means of the source of the bacteria is not the air and utensils, as Ostwald viscosimeter, and also b y means of various has been suggested in the literature, but the corn- commercial instruments which are unsuitable for meal used in making the batter. One organism was scientific research, although possessing a n ease of isolated which in pure culture produces the gas neces- manipulation very desirable in this work. The former sary t o properly aerate bread This bacterium instrument has been shown t o have only a limited deseems t o be a member of the coli group and was never gree of exactness’ which is not great enough t o obtain found in batters t h a t were heated t o 7 5 ” C. It in the relations between the viscosity of liquids and other all probability belongs to the same group as the or- physical or chemical properties and establish them ganism described b y Wolffin and Lehman, which on a firm basis. Bingham and White1 have described they call Bacillus levans. This organism could be a viscosimeter capable of measuring viscosity with propagated in liquid media, such as milk, or could the greatest accuracy, by which absobe grown in a batter and subsequently dried, t o be lute results are obtained; that is, a used in the preparation of bread. constant amount, of liquid is passed When the liquid used in making the batter is taken through a capillary tube of known sufficiently hot to bring the temperature of the batter diameter and length, the time of flow t o 7 5 O C. or higher, certain spore-bearing organisms being regulated b y a variable pressure prevail which readily produce the gas necessary t o which is adapted t o the nature of the aerate bread. These bacteria soon lose their gasliquid. Recently the authors of this H producing power when kept in liquid media or when paper has devised a n instrument of transferred t o fresh media a t intervals of 1 2 or 24 the same general type which can be hours. From this fermenting batter no culture was readily constructed and also is quite isolated t h a t retained its ability t o produce gas when exact. The calibration of the viscokept in the liquid state. A dry product consisting simeter, the method of manipulation, for the most part of starchy material was prepared, and data showing its accuracy were however, which could be used a t will in making unipresented in the previous article; also form bread. i t was used t o measure the viscosity Bread made b y the “Sauerteig” method differs of blood and blood serum and was from salt-rising in that the gaseous fermentation found t o be generally applicable for in the latter is due entirely t o bacteria, while in the t h a t work. former the leavening power owes its origin primarily I n this investigation the viscot o yeasts, and it is a question whether the bacteria simeter4 A, which was referred t o present, some of which are gas formers, are desirable above, was modified for the measureFi9 1 a r n o t ; they differ also in that the latter is made from ment of the viscosity of fish oils, which fresh material each time, while in the preparation of course are relatively very viscous of the formeq a portion of dough is saved t o start compared with water and aqueous t h e fermentation in the next baking. The same method of proP 5 solutions. The gases produced b y the salt-rising bacteria, cedure was followed in this work as in that with blood as found in these experiments, consist of nearly and blood serum, a known volume of liquid passing a / , hydrogen and rather more than I / 3 carbon dioxide through a capillary tube of known dimensions under a a n d no hydrocarbons. 1 Schmidt, dissertation, Baltimore, Md.. 1909. Bingham and Durham. The losses of materials, due t o decomposition and Am. Chem. J . , 46, 278 (1911). 2 J . A m . C k m . S o c . , 33, 1257 (1911). A more detailed description volatilization of some of the constituents, are much be published. smaller in salt-rising- bread than in bread made with will soon a B w c h . 2 ,37,482 (1911). yeast, and the losses in the latter vary with the amount 4 Ibid.,37, 483 (1911)
i
1
Feb., 1912
T H E J O U R N A L OF I N D U S T R I A L AATD ENGIAZ'EERING C H E . V I S T R Y .
given pressure and temperature. A new viscosimeter, B (Fig. I), was constructed on the plan of the previous one, b u t with a much shorter capillary tube and with the volumes of the limbs considerably less. The method of standardizing the instrument was similar t o the standardization of A in principle but water could not be used as the time of flow would be too short under the lowest pressures obtainable. Therefore, the viscosity of a sample of menhaden oil'was determined in viscosimeter A (which had been standardized with water), the temperature being 50' t o reduce the time necessary for measurement. The viscosity was found to be 0.1518 in the left limb and 0.1514 in the right limb-average 0,1516 a t 50'. Viscosimeter B was now calibrated with the above oil, and the following are the constants obtained for this instrument : Length of capillary (approx.). .................... Volume of left limb.. ............................ Volume of right limb.. . . . . . . . . . . . . . . . . . . . . . . . . . . Pressure correction, left limb. .................... Pressure correction, right limb.. . . . . . . . . . . . . . . . . . . Ratio of r' to 1 . . ................................
1.7 a. 2 . 1 3 1 0 cc. 2 , 0 7 4 8 cc. 1.2.3 cm. 1 . 2 0 cm. 0.00004577 0,00004582
This viscosimeter was found to give excellent results, the time of flow under a pressure of 100-180 cm. varying with the different oils from two t o six minutes, depending on the nature of the oil and the temperature.
aid of pressure. This separated the oil and water from the great quantity of proteid matter present, and allowed the oil t o rise in a clear layer t o the top of the mixture placed in large cylinders. Water was added to bring the oil t o the top of these latter, and the oil was siphoned off; allowed t o cool, and dried with calcium chloride for several days. The dried oil was then filtered from the salt and separated stearin or other insduble fats through filter paper with the aid of suction, and preserved in a,cool place for the resulting measurements. The oils generally varied in color from a very light yellow to a light brown. I n order to check up their composition a few constants were determinedthe iodine number (Hubl), the acid number (milligrams of potassium hydroxide required to neutral ize one gram of oil), and the saponification number (milligrams of potassium hydroxide necessary for one gram of oil). TABLEI . SaponificaKind of oil. Iodine No. Acid No. tion No. Menhaden I (commercial). . . . . . . . . . . . . . . 1 6 8 . 6 ... Menhaden I1 (dark). , . , . . . . . . . . . . 128.1 6.83 16.26 Menhaden I11 (light). . . . . _ ., , , . , , . 143.3 0.88 191.1 Whale (commercial). . . . . . . . . . . . . . . . . . . . 1 5 6 . 6 6.70 192.8 Cod liver (white, commercial) . . . 142.6 1.82 185.8 Cod liver (brown, commercial) . . . 150.9 9.83 189.8 Sperm (commercial). . . . . . . . . . ,.. 85.5 0.33 167.0 Dogfish ............................... 135.9 0.94 193.0 Dogfish liver I . . . 118.2 3.49 188.1
...
.
.
vd
The kinetic energy correction - in the formula 8ztl zr4@ vd Ti = 8v1- - G l was low, th,k being necessary if the work is t o be made as accurate as possible. This correction was always less than 0.5 per cent. of the total viscosity. I n the above equation 7 is the viscosity, Y and 1 are the radius and length of the capillary tube, ZI is the volume of liquid of density d , p is the pressure, and t is the time of flow. Viscosimeter B was tested a t 60' with the menhaden oil, the viscosity of which had been measured in viscosimeter A, and the following results were obtained :
'07
...............
Sand shark liver. Hammer-head sh
,
,
,,
.,.
,
, , , ,
., .
.. ..
SCUP................................. Butter-fish.. Eel ...........
..
..............
...........
..
124.8 53.9 142.7 213.6 155.5 111.0 92.8 103.9 117.3 91.1 117.4
1.60 1.96 4.84 1.52 3.32 0.92 0.75 7.40 16.73 62.07 1.02
189.9 189.4 171.4 182.7 174.1 164.0 160.9 196.5 188.9 191.4 191.1
I n the following tables are given figures showing the viscosity of the oils as measured in the right and left limbs of the viscosimeter a t 30°, s o o , 7 0 ° , and goo, with the average of these a t each temperature respectively, and with the corresponding fluidity. The specific gravity, as measured in the ordinary Ostwald pycnometer, is also given, as i t was necessary for obtaining the kinetic energy correction inVISCOSITY OF MENHADEN OIL. volved in the formula for the calculation of the visRt. limb. Left limb. Av. cosity. The bath containing the viscosimeter was a Viscosimeter A . ...................... 0.1169 0.1168 0.1169 Viscosimeter B . ..................... 0.1170 large beaker of water well stirred b y a suitable stirrer. 0.1166 0.1168 Viscosimeter B . ..................... 0.1164 0.1165 0.1165 The temperature was regulated b y hand since the The average of the four measurements in B, 0.1167, time of measurement a t any one temperature was so is in satisfactory agreement with the result obtained brief as t o make a n automatic regulator troublesome. The temperature was kept constant to 0.02', and with the other viscosimeter, 0 .I 169. great care was exercised t o insure this, the temperaI n general. the oils used for this investigation were extracted from fish obtained at Woods Hole, except ture coefficients of viscosity of these oils being very the samples of cod, whale, and sperm oils, which were large. commercial products. The entire fish or the fish TABLE II.-MENHADEN I , COMMERCIAL (Brevooriia fyrarrnus). livers, according t o the oil desired, were subjected t o Viscosity. steam pressure in a n autoclave a t 115' for 2-4 hours R . L. L. L. Av. Fluidity. Sp. gr. and then filtered while hot through cloth with the Temp. sample of oil, among others, was furnished b y Mr. J. F. Goode, with the firm of Marden, Orth & Hastings, Boston, Mass., whose favor is gratefully acknowledged. 1 This
........ 0 . 2 9 5 8 ......... 70 '........ 0.09559
30 500..
90
........
0,06357
0.2965
...
0.09551 0.06343
0.2961 0.1516 0.09555 0.06350
, 3.377 6.597 10.47 15.75
0.9177 0.9076 0.8931 0.8798
T H E J O G R I Y A L OF I N D U S T R I A L A N D E;VGI,VEERISG C H E M I S T R Y .
I08
TABLEIII.--MENHADENI1 (DARK) . Viscosity .
Temp. 30 '. . . . . . . 50 '....... 70 '. . . . . . . 90 . . . . . . .
...... 5 0 ' . ......
30'.
70 " .......
900
.......
. R . L.
L. L . 0.6025 0.2938 0 ,1683 0.1096
AV. 0.6019 0.2935 0.1683 0.1097
.
.
SP . gr 0.9371 0.9234 0.9097 0 .8965
TABLEIV-MENHADEN I11 (LIGHT) . 3.088 0 ,3233 0.3238 5 ,790 0.1727 0.1727 0.1727 9.533 0 ,1049 0.1049 0 ,1048 0.07097 14.09 0.07101 0.07092
0.9230 0 .9090 0 .8454 0.8824
.
0 ,3243
TABLEV.-%"ALE, COMMERCIAL (Balaeno mysficeiuh). 2.859 0.9192 0.3485 0.3493 0.3477 5.489 0.9063 0.1824 0.1822 0.1818 0.8912 0.1101 9.090 0.1103 0.1099 0.8782 0.07241 13.81 90"........ 0.07243 0.07328
........ 50° ........ 70"........
........ ........
callarias) . 2.575 4.992 8.418 12.71
0.9277 0.9149 0.9008 0.8900
TABLEVII.-COD LIVER.BROWN(COMMERCIAL) . 30° ........ 0.3924 0.3924 0.3924 2.549 0.9162 5 0 ° ........ 0.2078 0.2080 0.2079 4.810 0.9034 70 ........ 0.1196 0.1194 0.1195 8.368 0.8911 90" 0.07866 0.07843 0.07855 12.73 0.8769
........
TABLEVI11 -SPERM. COMMERCIAL(Physeter 0.3333 0.3333 0.3333 0.1720 0.1719 0.1721 0.1037 0.1038 0.1039 0.06655 90". . . . . . . . 0 .06647 0.06662
........ 50° ........ 70° ........
30°
.
.
0.9160 0.9016 0.8884 0.8758
TABLEXI-DOGFISH LIVERI1 0.3762 2.659 0.3761 0.3762 0.1977 5.059 0.1977 0.1977 0.1161 8.614 0.1160 0.1161 0.07740 12.92 0.07729 0.07750
0.9164 0.9038 0.8902 0.8768
70° ........ 90". . . . . . . .
........
30° ........
........
50°
........
70 O 90 ........
30 O
........ .
50°.......
70 O . . . . . . . . 90°........
TABLEXII.-DOGFISH LIVERI11 . 0.3776 2.649 0.3771 0.3781 0.1943 5.147 0.1941 0.1944 0.1154 8.666 0.1153 0.1155 0.07638 13.09 0.07628 0.07648
0.9162 0.9128 0.8876 0.8750
TABLEXI11 .- SPINYDOGFISH LIVER (Spualus acanlkim). 0.4000 0.3986 0.3993 2.504 8.9187 5 0 ° . . . . . . . . 0.2045 0.2053 0.2049 4.880 0.9074 0.1215 0.1214 8.237 0.8945 70°........ 0.1213 0.07965 0.07949 0.07957 12.56 0.8820 90
30 "
........
........
TABLEXIV.-SAND SHARKLIVER ( C a r c h r i m liiforalk). 30" ........ 0.3675 0.3680 0.3678 2.719 0.9262 SOo 0.1943 0.1942 0.1943 5.150 0.9135 70° 8.497 0.9005 0.1177 0.1176 0.1177 0.07916 0.07916 0.07916 12.63 0.8867 90°
........ ........ ........
TABLEXV.-HAMMER-HEAD SHARK LIVER (Sphyrna a~uaema) . 30° 1.828 0.9245 0.5479 0.5461 0.5470 5O0 0.2682 0.2684 0.2681 3.730 0.9122 70° 0.1534 0.1539 0.1537 6.507 0.8986 90° 0.09787 0.09800 0.09794 10.21 0.8863
........ ........
........ ........
R . L. 0.4257 0.2134 0.1256 0.08071
L. L . 0.4269 0.2131 0.1258 0.08075
AV . 0.4263 0.2133 0.1257 0.08073
.
Sp. gr 0.9044 0.8923 0.8762 0.8676
Fluidity 2.345 4.688 7.956 12.39
TABLEXVII.-TORPEDO LIVERI1 0.4775 0.4773 0.4774 2.094 0.2356 0.2356 0.2356 4.244 0.1381 0.1377 0.1379 7.252 0.08756 0.08746 0.08751 11.43
0.9018 0.8890 0.8764 0.8644
TABLEXVIII.-SQUETEAGUE(Cynoscion regalis) 30 . . . . . . . . 0.4975 0.4985 0.4980 2.008 50 " . . . . . . . . 0.2405 0.2399 0.2402 4.164 70 O . . . . . . . . 0.1382 0.1385 0.1384 7.225 90°... . . . . . 0.08904 0.08914 0.08099 11.22
.
TABLEXIX.-Scup (Stenotomus chrysobs) . 30'. . 0.4193 0.4197 2.384 0.4195 50 O . . . . . . . . 0.2138 0.2143 0.2141 4.671 70 0.1239 0.1239 0.1239 8.071 90'. 0.08129 0.08119 0.08124 12.31 TABLEXX.-BUTTER-FISH 0.4274 0.4257 0.2092 0.2091 70". . . . . . . . 0.1194 0.1193 90 '. . . . . . . . 0.07624 0.07602
0.9177 0.9048 0.8910 0.8784
0.9168 0.9040 0.8910 0.8740
........
(Poronoius tricanthus) 0.4266 2.344 0.2092 4.780 0.1194 8.375 0.07613 13.13
. 0.9090 0.8962 0.8824 0.8704
.
......
TABLEX.-DOGFISH LIVERI . 0.4096 2 . 441 0.4103 30"........ 0.4089 0.2072 4.826 5 0 ° . . . . . . . . 0.2069 0.2075 0.1212 8.251 0.1211 70° 0.1213 0.07972 12.55 90"........ 0.07971 0.07973
........
50°
........ ........
30". . . . . . . . 50 '. . . . . . . . 70 O . . . . . . . . go0..
3 00 '5.814 9.636 15.03
0.9185 0.9057 0.8932 0.8796
TABLEIX.-DOGFISH 0.4319 0.4319 0.2138 0.2133 0.1262 0.1259 0.08293 0.08272
70 90
macrocephalus)
(Musfelus canis) 0.4319 2.315 4.682 0.2135 0.1261 7.931 0.08283 12.08
30"........
Temp . 30". 50 O . . . . . . . . 70 O ........ 90 '. . . . . . . .
.
30
TABLEVI.-COD LIVER.WHITE(Gadus 0.3884 0.3882 30° ........ 0.3886 0.2005 0.2003 50 0.2001 0.1189 0.1188 70 O ........ 0.1187 0.07872 0.07882 90° 0.07862
1912
TABLEXVI.-TORPEW LIVERI (Tetranarce occidenialis) . Viscosity
Fluidity 1.661 3.407 5 , 945 9.107
0.6012 0.2936 0 , 1683 0.1097
Feb.,
TABLEXXI.-EEL (Anguilla rosfrata) 0.4017 0.4012 0.4015 2.491 0.2026 0.2026 0.2026 4.938 0.1188 0.1185 0.1187 8.425 0.07805 12.81 0.07800 0.07803
0.9135 0.9012 0.8880 0.8750
The viscosity measurements were made a t practically the same time as when the other constants were determined, since the viscosity changes slowly, due to the decomposition of the oils . The following determinations of the viscosity of sperm oil taken two weeks after those, the results of which are given in Table V I I I , show this, the later values being larger . TABLEXXII.-VISCOSITY Temp . R L. 30'. .................... 0.3417 500 . . . 0.1751 70'. .................... 0.1032 90'. .................... 0.06667
.
OF
.
SPERMOIL L. L . 0.3424 0.1754 0.1029 0.06661
Av . 0.3421 0.1753 0.1031 0.06664
The question also arises whether the oils do not change in composition in being heated from 30 O-90 O , in such a way as to affect their viscosity, thereby introducing a complication into the study of the viscosity curves. That this is not the case may be seen from the following values for the viscosity of butterfish oil taken a t 30' after measurements had been made on the same sample of oil from 30' u p to 90'.
. .
L L 0.4282
R . L. 0.4285
Av . 0.4284
The average value before heating was 0.4266, and the difference is therefore very small . I n one instance, that is with the sand shark oil, on standing for several weeks the oil became cloudy and there was deposited some solid fat . This was filtered from the liquid fats and measurements were taken again with the following results :
Feb., 1912
T H E J O C R S A L OF I-VD L - S T R I A L A N D E - Y G I S E E R I N G C H E M I S T R Y .
109
TABLE XXIII.--T'ISCOSITY OF
SAND S H A R K LIVEROIL (AFTER FILTRATIONmental data, t h a t pure homogeneous liquids, which SEPARATED SOLIDS). are not associated, have a fluidity which is a linear Temp. L. L. R. L. Av. function of the temperature, the corresponding vis0.3698 3 0 ° . . . . . . . . . . . . . . . . . . . . . 0.3703 0.3693 cosity curve being hyperbolic. With liquids which 0.1946 500 . . . . . . . . . . . . . . 0.1942 0,1950 70'. . . . . . . . . . . . . . . . . . . . . 0.1179 0.1184 n.1182 are associated the fluidity curve deviates from a 0.07981 0.07986 900.. . . . . . . . . . . . . . . . . . . . n .07990 FROM
The viscosity is in surprising agreement with that before the separation of the solid fats and about a half a per cent. higher. The influence of the degree of refinement of the oil on its viscosity is shown by the values for the two cod oils. Here again i t is clear t h a t the viscosimeter used is capable of making small differences in viscosity evident. That the method for the extraction of the oils from the fish gave oils of characteristic viscosity is evidenced b y the closely agreeing values for the various dogfish liver oils, which were obtained from different fish and extracted in the autoclave a t different times, These oils were all a very light brown and no solids separated from them on standing. They also show close agreement in the values for the saponification number and the acid number. This is true of the two samples of torpedo oil although the viscosities do not agree so well. This latter fact is very probably due t o physiological variances of a n exceptional character, since one liver yielded apparently an abnormally large quantity of oil, while the other gave much less. Menhaden oils I and I11 approximated each other in color and in viscosity, whereas Menhaden :I1 had a viscosity t h a t was very high. This is explained by the fact t h a t the last oil was extracted a t a much higher temperature (130') than the other two: whereby there was considerable decomposition and the oil became quite gummy. The liver oils from the different members of the same family may be compared. I n the shark family, the viscosities of the smooth dogfish, the spiny dogfish, and the sand shark liver oils are in the same order of magnitude, while t h a t of the hammer-head shark is much higher than any of these. The values for the commercial whale and sperm oils, presumably refined according to similar methods, are very close t o each other. A further study will be made of this problem. No relation between the viscosity and the iodine number is apparent, as has been suggested b y some investigators. The results of the viscosity measurements were plotted and are shown in Fig. 2 , the ordinates representing fluidities and the abscissas temperatures. The curve for each oil is numbered according t o the table in which the viscosity values were presented. The graphs show t h a t the fluidity of the different oils varies with the temperature in approximately the same way, and not linearly, the increase in fluidity being proportionally greater a t the higher temperatures. The fluidities, and not the viscosities, were taken into consideration in view of Bingham's theories on the relations between fluidity and composition.' He believes, and has supported his belief with experi'2.physik. Chem., 66, 1 (1909)
straight line to a degree dependent on the association. Assuming then t h a t there is no chemical change in heating the oils from 30-90°, which was essentially proved in the case of the butter-fish oil, there is good evidence for the belief t h a t these oils are more or less I!
I ,
I
//
llIl
iV V
(1I
