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 Y
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TABLE 111-PHYSICAL AND CHEMICALPROPERTIES OF MIXSD ACIDS (INSOLUBLE ACIDS) OF OILS FROM CORNSAMPLES Specific Neutralization Iodine ODOR TASTE Gravity Refraction Value Value 1 Light yellowish brown Fatty Bland, fatty 0.9038 1.4659 184.8 129.1 (220 C.) (220 C.) F a t t y , bland, becoming bitter 0.9055 1.4653 183.2 142.2 2 Brownish red Fatty, not agreeable (23O C.) (23' C.) F a t t y , becoming bitter and 0.907 1 1.4672 188.8 126.6 3 Reddish brown Fatty, disagreeable, musty unpleasant (24' C.) (24' C.) Very bitter, f a t t y 0.9169 1.4700 186.5 122.9 4 Brown Disagreeable, fatty, rancid (23' C.) (23' C.) 5 Dark brown Rancid (semi-solid) Disagreeable, bitter 114.8
OIL
SAMPLE COLOR
OIL Yield SAMPLEPer cent COLOR 1 84.4 Light reddish brown 2 3 4 5
80.0 79.5 82.7
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ODOR Mild, fatty
TABLSV-PHYSICAL Yield Per cent 11.1 10.3 12.6 9.09
SAMPLE I . . . . ................... 2 3 4 5
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CHEMICALPROPERTIES OF LIQUID ACIDS OF OILS Specific Neutralization TASTS Gravity Refraction Value F a t t y , slightly acid, becoming 0.9105 (22' C.) 1.4674 (22" C.) 184.4 bitter F a t t v , becoming bitter 0.9087 (23'C. 1.4670 23OC.1 185.8 F a t t y , bitter 0.9110 (24" C. 1.4665 124' C.) 175.3 0.9194 (23'C. 1.4730 (23OC.) 171.7 Fatty, becoming bitter
AND
Brownish red F a t t y bland Dark brown Faint,' fatty Dark brown Unpleasant, fatty Insufficient oil for separation of liquid acids
OIL
...
....
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TABLEIV-PHYSICAL
AND
1
Iodine Value 146.5 153.0 135.3 132.8
CHEMICALPROPERTIESOF SOLIDACIDS OF OILS
APPEARANCE ODOR Pale yellow, tallow-like None Pale yellow, waxy None Pale yellow, waxy None Darker yellow None Insufficient oil t o make separation of solid acids
In saponification values the same general increase is noted in Samples I , 2 , and 3, followed by a decrease in Sample 4 and a sharp decline in Sample 5 , indicating a consumption or decomposition of the glycerides a t this point. The iodine values remain almost constant in the first three samples, with a decided decrease in Samples 4 and 5 , indicating a lowering of t h e content of unsaturated acids. The high percentage of volatile acids in the original oil and the extremely sharp decrease, remaining almost constant, in the remaining oils points t o the possible decomposition of these constituents by the mold as rapidly as formed. The formation of soluble acids apparently was assisted by the gradual spoilage of the corn. The formation of insoluble acids, on the other hand, appears t o have been retarded slightly after the molding began, The acetyl value, which is a measure of the hydroxylated glycerides, exhibits noteworthy fluctuations, being especially high in Samples 3 , 4) and 5 , showing a rapid formation of these constituents as the experiment progressed. One of the most remarkable changes brought about by the growth of the mold was the formation of unsaponifiable substances in t h e oils, a steady increase t o 25.4 per cent having been found. I t is very probable t h a t the solid matter mentioned in the discussion of Table I, and which was observed increasing in each sample of oil, consisted largely of unsaponifiable substances elaborated from the oil by the mold.
LIQUID AND SOLID ACIDS O F OILS
A separation of the liquid and solid acids was made from the insoluble acids by methods prescribed by t h e Association of Official Agricultural Chemists. The physical and chemical properties of the liquid acids were determined (Tables IV and V).
Melting Point Deg. C. 55-58 55-56 52-55 53-56
Neutralization Value 207.9
208.4 214.2
...
The yields of liquid acids are shown t o fluctuate considerably, a lower yield being indicated in oil from the moldy corn. The color, odor, and taste are also more pronounced in the moldy samples. A slight increase is observed in the specific gravity and refraction of the most moldy samples. The neutralization values and also t h e iodine values of these same samples are noticeably lower t h a n the acids from less spoiled samples, indicating a decomposition of these acids during spoilage. The yields of solid acids from the respective oils likewise differ, a perceptible drop being observed in Sample 4. The melting points also fluctuate. Neutralization values show slight increase as the spoilage continued, showing t h a t a material effect was being produced even on the solid acids of the oils. CONCLUSIONS
It may be stated t h a t the effect of the spoilage of corn from the growth of mold was noticeably manifested in connection with t h e f a t t y oil. A consumption of oil by the mold was apparent, as manifested by the decrease in the yield of oil a t each stage of decomposition. As regards composition of the oil, spoilage of the corn caused very decided increase in the free acids, the soluble acids, hydroxylated acids (acetyl value), and unsaponifiable constituents, with a decrease in the percentage of volatile acids, insoluble acids and unsaturated acids. INSOLUBLE SOLIDS IN JAMS, PRESERVES, AND MARMALADES By C. A. Clemens
I N S O L U B L E ACIDS O F OILS F R O M CORN SAMPLES
The insoluble acids (mixed acids) obtained from each sample of oil were subjected t o physical and chemical examination (Table 111.)
TASTE Tallow-like Tallow-like Tallow-like Tallow-like
SOUTH DAKOTA FOOD AND DRUGDEPARTMENT, VERMILION, S. D . Received August 9, 1919
The official method for the determination of insoluble solids in fruit products' is slow and cumbersome. A method has been worked out which is rapid, easily manipulated, and a t the same time obviously offers greater accuracy. By the substitution' of a n alundum crucible for a linen filter i t becomes possible t o apply suction and a t the same time t o have a better filter1
J . Assoc. O f i c i a l Agr. Chemists,[2] 2, 177.
Jan.,
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 Y
1920
ing medium, also t o avoid one transfer of the insoluble residue. The only questionable point in the new procedure was the boiling of the sample instead of macerating with warm water, and this was shown by comparison of results with the official method t o be permissible. This part of the procedure also avoids unnecessary transference of the residue. PROCEDUXE
Twenty t o twenty-five grams of the thoroughly macerated sample are weighed out into a 250-cc. beaker, I O O cc. distilled water added, the mass stirred, and t h e beaker covered with a watch glass. The solution is brought t o a boil and allowed t o boil for 5 min., when it is removed and transferred t o an alundum crucible t o which suction is applied. The residue is thoroughly washed with boiling water followed by IO cc. alcohol and ether, respectively, dried in a water oven, cooled, and weighed. Table I shows results obtained by this and the official method. TABLE I A. 0. A. C. PROPOSED NATURE O F SAMPLE METHOD METHOD Annle-blackberrv Dreserves. 0.57 0.58 Apple-blueberry preserves, 0.28 0.27 Apple-gooseberry preserves. 0.27 0.28 Apple-loganberry preserves. 0.14 0.18 Apple peach preserves. 0.31 0.26 Apple-raspberry preserves, 1.20 1.25 Apple-raspberry preserves. 0.88 0.88 DreServeS 0.48 0.50 -Annle-rasDberrv -=* Apple-raspberry preserves. 0.64 0.60 Apple-raspberry preserves. 0.70 0.70 Apple strawberry preserves. 0.29 0.29 0.64 0.64 Apple-strawberry preserves. 0.31 0.32 Apple-strawberry preserves. 0.93 0.94 ADDle-strawberrv oreserves. Apple.strawberry preserves. . . . . . . . . . . . . . . 0 . 2 0 0.20 Apple butter.. 2.36 2.17 Glucose raspberry apple j a m . . 1.10 1.09 Orange marmalade. 1 .OS 1 .oo Orange marmalade.. 3.50 3 .55 Raspberry preserves,. 1.72 1.70 Raspberry preserves. 3.85 3 .87 Strawberry preserves.. 0.89 0 .89 Strawberry preserves. .................... 1.85 1.81 I
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A CHEMICAL STUDY OF THE ETHER EXTRACTS OF SOY BEAN LEAVES‘ By E. M. Nelson UNIVERSITY OF WISCONSIN, MADISON, WISCONSIN Received July 5, 1919
The scarcity and high price of linseed oil during the last few years have led t o extensive investigations directed toward obtaining a substitute which can be used in paint manufacture. Linseed oil has a high iodine number and forms a hard film upon drying; as yet no other oil has been obtained in large quantities which possesses these desired qualities. Soy beans give promise of becoming a n important crop in this country because of the ease with which they can be grown and their high food value, and since they contain from 15 t o 2 0 per cent of oil having an iodine number roughly from 115 t o 145, attention is being given t o the possibility of improving the quality of the oil by breeding. While engaged in making analyses of beans from pure lines and crosses grown by the Department of Genetics of the local Agricultural Experiment Station, t h e high iodine number of the 1 Published with the approval of the Director of the Wisconsin Agricultural Experiment Station.
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ether extract of soy bean leaves suggested a possible source of a highly unsaturated oil. Ether extract waxes as well as oils, but if these latter compounds were made up of highly unsaturated fatty acids t h a t fact might be of sufficient importance t o warrant the perfecting of a method of separating them from other substances. A study of this problem shows t h a t the highly unsaturated compounds obtained in a n ether extract are not oils, but probably belong t o the alcohol group of the waxes. Upon saponification of a mixture of waxes and oils as obtained from an ether extract of soy bean leaves with a base such as caustic potash, soaps which are insoluble in ether are formed from the fatty acids of the oils and waxes. Chlorophyll also forms a n etherinsoluble compound. The higher alcohols are set free and together with carotin can be extracted with ether. This affords a method for the partial separation of the f a t t y acids from the other material. The following procedure was carried out t o determine the possible relation of the fatty acids t o the high unsaturation of the ether extract of soy bean leaves. Leaves were collected from separate plants which were quite mature and dried a t about 18” C. with the aid of an electric fan. When thoroughly dried the leaves were ground in a mill in such amounts as were t o be used immediately. Only freshly ground material was used t o prevent oxidation from atmospheric oxygen. Four or 5 g. were then extracted for 16 hrs. with about 2 0 cc. of anhydrous ether in a Soxhlet extractor, and the extract received in a IOO cc. Erlenmeyer flask. The ether was evaporated and the material saponified by boiling gently for an hour over a water bath with 2 5 cc. of alcoholic potash with a reflux condenser attached. The alcohol was then evaporated and the residue dried over night in a vacuum desiccator. I n the morning about 50 cc. of water were added and the contents of the flask transferred t o a separatory funnel, washing several times with water and ether. The aqueous solution with the insoluble material was then extracted with several 5 0 cc. portions of ether until there was no trace of color in the extract. The ether was distilled from the unsaponifiable material, the residue dried over night in a vacuum desiccator, and the iodine number determined according t o the method of Hub1 as described in Sherman’s “Organic Analysis” (Revised). Ten cc. of 2 0 per cent sulfuric acid were added t o the saponifiable material and extraction with ether and the iodine number determination completed as with the unsaponifiable matter. Methods for this kind of work are not standardized as the nature of the material from different plants varies t o such a n extent t h a t different courses of procedure have t o be carried out. It was found t h a t by using from 4 t o 5 g. of dried leaves about 0 . 2 g. of extract was obtained and t h a t this was the most convenient amount t o handle without loss and on which t o determine the iodine number, Some difficidty was experienced in extracting the unsaponifiable matter with ether because of the tendency t o form a n
