THE CHEMICAL WORLD THIS WEEK
M e m b e r s of the committee w h o have b e e n correlating research on spectrop h o t o m e t r i c m e t h o d s of determining oil color for the past year. S e a t e d : G. W. Agee, Barrow-Agee Laboratories; Felix P a q u i n , F . P a q u i n & Associates; Procter T h o m p s o n , Procter & Gamble; standing: F . R. E a r l e , Northern Regional Research Laboratory; and R. C. Stillman, Procter & Gamble
Spectrophotometric Method for Vegetable Oil Color Adopted C&EN REPORTS: American Oil Chemists' Society ATLANTA.—A spectrophotometric method for determining t h e color of vegetable oils to replace t h e L o v i b o n d method was a d o p t e d b y the American Oil Chemists* Society at its forty-first annual meeting here May 1 to 3. T h e addition of vitamins to margarine, fractionation of cottonseed, the flavor problem of soybean oil, and gourd seeds as a potential source of oil were other topics of high interest. Since t h e spring of 1949 the society's oil color subcommittee has been correlating work in nine different laboratories on the improvement of t h e interpretation of spectrophotometric readings for color determination. O n t h e basis of these studies it w a s found that t h e most satisfactory equation involved measurements at 460 ? 550, 620, a n d 670 m/x. A n equation for photometric color using these four measurements was found to give a correlation of 0.993 with Lovibond and has b e e n adopted. T h e r e was no processing loss of vitamin A a d d e d in t h e manufacture of margarine on a pilot-plant scale in studies reported by Kenneth Morgareidge and C. Gilmore of Nopco Chemical Co. and Durkee F a m o u s Foods, respectively. Margarine c o m p o u n d e d according to a typical allvegetable oil formula a n d produced with a small pilot-scale Votator was enriched with e ; ght different vitamin A concentrates, including both ester a n d alcohol forms, V O L U M E
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and one sample of t h e synthetic vitamin A palmitate. In the assay of both concentrates a n d finished margarines, it was found that t h e colorimetric m e t h o d overestimates t h e U.S.P. potency by about 2 5 % , it was reported. It was indicated that this will become an important consideration from a product control viewpoint with t h e introduction of t h e U.S.P. XIV assay as t h e basis of commercial transactions involving vitamin A. F u r t h e r intensive work toward a more specific assay p r o c e d u r e was emphasized. A preliminary cost study of a combination screw-press extraction-fractionation plant for the handling of cottonseed was m a d e b y R. M. Persell, H . L. E . Vix, C. G. Reuther, and E. F . Pollard of t h e Southern Regional Research Laboratory. T h e economic advantage of the combination plant over the screw-press operation was indicated to be small in comparison with t h e large additional investment required for t h e combination plant. T h e present value of the combination process was said to lie in the production of two new products, a purified high-protein meal and a concentrated pigment gland fraction, and in t h e possibility of producing a high grade oil as t h e removal of the whole pigment gland prevents the pigment material from coming in contact with t h e oil. Pilot plant work was reported to indicate improvements in t h e process. In the latest report on progress on the . M A Y
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flavor problem of soybean oil from t h e Northern Regional Research Laboratory, II. J. Dutton, C. R. Lancaster, C. D. Evans, and J. C. C o w a n presented for t h e first time data supporting a definite statement that linolenic acid is a precursor of "reversion" flavors in soybean oil. This was shown b y : ( I ) a qualitative study of the flavors after storage of soybean oil in which the linolenic acid content has been significantly lowered b y furfural extraction, and ( 2 ) organoleptic identification studies of stored soybean oil, stored cottonseed oil, and stored cottonseed oil into whose glyceride structure linolenic acid had been introduced b y t h e use of an intersterification catalyst. T h e relative hydrogenation rates of normal and conjugated linolenic and linoleic acid glycerides w e r e studied by S. YV. Thompson of Lever brothers Co. A mixture of 50c/o tung oil and 5 0 % linseed oil was hydrogenated a n d samples were withdrawn a t approximately 10-iodine value intervals during the course of the reaction. T h e samples were analyzed for fatty acid composition and the reactivity ratios for the various fatty acids w e r e calculated. T h e results indicated generally t h a t the amount of conjugation a n d unsaturation in the glyceride rather t h a n in t h e individual fatty acid may b e t h e controlling factor in hydrogenation selectivity. A study of t h e seeds of the Buffalo gourd, Cucurbita joetidissima, was reported by H. S. S h a h a n i a n d F . G. Dollear of the Southern Regional Research Laboratory a n d J. Roy Q u i n b y of t h e Texas Agricultural Experiment Station. T h e oil was shown t o have an iodine value of 136.1 which places it in t h e semidrying class along with, but slightly above, soybean oil. T h e crude oil w a s very dark in color a n d resistant t o bleaching. Refining, bleaching, a n d deodorization gave a bland oil with good stability a n d n o tendency to revert in flavor. However, t h e color at each stage of processing w a s inferior to that of other c o m m o n edible oils such as cottonseed, p e a n u t , a n d soybean. Hydrogenation to shortening consistency gave a fat of excellent stability w h i c h was likewise inferior in color to other common hydrogenated oils. Seeds from t h e same gourd, as well as those of C. palmata a n d C. digitata were conjugated by D . S. Bolley, R. H . McCormack, a n d L . C. Curtis of t h e National Lead Co., as sources of drying oils and proteins. It was stated t h a t all three oils h a d properties t h a t would m a k e t h e m of interest as d r y i n g oils. I n a stuc'y of t h e compatibility of a number of alkyl and alkenyl esters and related compounds with commercial polymers b y H. B. Knight, R. E. Koos, E. F. Jordan, Jr., and D. Swern, of t h e Eastern Regional Research Laboratory, t h e most promising results were shown by methyl9,10(10,9) - methoxyhydroxy - stearate, esters of 9,10-dihydroxystearic acid with ethylene glycol m o n o b u t y l ether and ethylene glycol monobenzyl ether. 1743
