Relative reduction rates of fatty acid isomers by hydrazine

Mixtures of fatty acids and of hydrocarbons have been reduced by hydrazine in ethyl alcohol solution at 50 C. Samples were removed during reduction for analysis and the relative reduction rates calculated by digital computer.cis-15-Octadecenoic acid is reduced 1.3 times as fast as itscis-9-isomer. No differences were found amongcis-6,9- and -12-octadecenoic acids.cis-3-Octadecene was also reduced 1.3 times as fast as thecis-9-isomer andcis-1-octadecene 8.6 times as fast. Elaidic acid was reduced 1.27 times as fast as oleic. Presented at the AOCS Meeting, Chicago, October 1967. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Fluorescence as a measure of brown substances in soybean lecithin

Summary The fluorescence of soybean lecithin increases in a linear fashion with an increase in brown substances. Since the measurement of fluorescence is simple and rapid, this measurement should prove a useful index of browning. The term “lecithin” is used throughout this paper to refer to the mixtures of phosphatides, oil, etc., known in the trade as soybean lecithin. It does not refer to phosphatidylcholine. Presented at fall meeting of American Oil Chemists' Society, October 11–14, 1954, in Mineapolis, Minn. One of the branches of the Agricultural Research Service, U. S. Department of Agriculture.     

Preparation of 9,15-octadecadienoate isomers1

Linolenic acid was reduced with hydrazine to produce a mixture containing a max of dienoic acids. After methylation this mixture was separated into trienoic, dienoic, monoenoic, and saturated esters by countercurrent distribution (CCD) with acetonitrile and hexane. The dienoic ester was further fractionated by CCD with methanolic silver nitrate and hexane to separate purecis,cis-9,15-octadecadienoate and the equimixture ofcis,cis-9,12- and 12,15-octadecadienoates. Following isomerization of thecis,cis-9,15-octadecadienoate with selenium, the geometric isomers were fractionated by CCD with methanolic silver nitrate and hexane. Puretrans,trans and purecis,cis isomers were isolated, as well as an unresolved mixture ofcis,trans andtrans,cis isomers. The characteristics of these isomers and related compounds are compared as determined by CCD, IR absorption, and capillary gas-liquid chromatography (GLC). Presented at the AOCS meeting in Minneapolis, 1963. A laboratory of the No. Utiliz. Res. and Dev. Div., ARS, USDA.     

Glyceride structure of vegetable oils by countercurrent distribution. V. Comparison of natural,interesterified, and synthetic cocoa butter

The glyceride structure of cocoa butter is of considerable practical importance and of particular theoretical interest Countereurrent distribution, gas chromatography, and isotopic dilution methods are employed in its study. The observed fractionation of glycerides is acounted for by assuming that palmitie and stearic acids are randomly esterified on the 1 and 3 positions of glycerol and that oleic is on the 2 position, as demonstrated by other workers. Complete randomization of the specifie structure of cocoa butter through the application of interesterification eatalysts greatly alters its physical A glyceride synthesized according to the “1,3 random palmitostearo-2-olein” concept has properties similar to natural cocoa butter. Presented before Division of Agricultural and Food Chemistry, American Chemical Society Meeting, Cleveland, O., April 5–14, 1960. This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U.S. Department of Agriculture.     

Components of “soybean lecithin”

Summary The acetone-insoluble material from soybean “lecithin” has been fractionated by submitting alcohol-soluble and alcohol-insoluble portions to countercurrent distribution between hexane and methanol. The alcohol-soluble portion was found to contain lecithin, cephalin, and sugars or glycosides; the alcohol-insoluble portion was separated into two major inositol-containing phosphatides and sugars or glycosides. While the commonly accepted value of 30–35% for lecithin in the phosphatides was confirmed, it appears that the accepted value of 65% of cephalin needs revision. The approximate composition for one sample of soybean phosphatides is estimated to be 29% lecithin, 31% cephalin, and 40% inositol-phosphatides. Presented at the 39th Annual Meeting of the American Oil Chemists' Society, May 4–6, 1948, in New Orleans, Louisiana. This paper reports results obtained from a research project financed by the Research Marketing Act of 1946. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

Equivalent chain lengths of methyl octadecadienoates and octadecatrienoates

Equivalent chain lengths (ECL) have been determined for a number of methyl octadecadienoates and octadecatrienoates with different stationary phases, including Apiezon L, polyphenyl ether, diethylene glycol succinate, XF 1150, 100% cyanoethyl silicone and tetracyanoethylated pentaerythritol. ECL values for unconjugated esters are slightly larger than calculated by adding the ECL increments over stearate found for octadecenoates with the same position and configuration of double bonds. In general, differences are greater for methylene-interrupted double bonds and fortrans double bonds. They are greater for more polar columns. Average corrections can be added so that calculated ECL values agree well with the determined values. ECL increases with polarity of the stationary phase. The relative ECL pattern on different stationary phases changes little with position of double bonds in the isomers, but it is affected by double bond configuration. For esters with the same double bond positions isomers withtrans double bonds tend to have lower ECL values thancis on polar stationary phases and higher ECL values on nonpolar. ECL’s of conjugated octadecadienoates are always higher than unconjugated and increase in the ordercis,cis; mono-trans; andtrans,trans. Presented at the AOCS Meeting, Chicago, September 1970.     

Reactions of conjugated fat acids

Summary 1. Addition products of ethyl crotonate and crotononitrile with conjugated methyl linoleate, derived from soybean methyl esters conjugated with a nickelcarbon catalyst, were prepared. 2. The addition product of ethyl crotonate and nonconjugated methyl linoleate was prepared and compared with that from conjugated methyl linoleate. 3. The addition product of ethyl crotonate and conjugated methyl linoleate was saponified to a dibasic acid which was used to prepare a decamethylene glycol polyester and an ethylene diamine polyamide. 4. The compatibility of the addition product of ethyl crotonate and conjugated methyl linoleate with various synthetic resins was determined. One of the laboratories of the Bureau of Agricultural and Industrial Ohemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

Chromatographic separation ofcis andtrans fatty esters by argentation with a macroreticular exchange resin

Methyl oleate and methyl elaidate, as well as other monoenecis andtrans isomers of fatty esters, can be separated quickly and conveniently by a preparative chromatographic procedure in which a silver-saturated ion-exchange resin is used. Separations are based on differences in stabilites of the silver-olefin complexes. Recoveries of better than 95% were made, and puretrans andcis monoene fractions were collected. This method can be used to separate saturates fromcis andtrans monoenes. Thecis,trans,cis,cis, andtrans,trans-9-12-octadecadienoates were separated. Whilecis,trans andtrans,trans dienes were cluted separately, thecis,cis diene isomer remained on the column. Presented at AOCS Meeting, in Minneapolis, 1963. A laboratory of the No. Utiliz. Res. and Dev. Div., ARS, USDA.     

Composition of soybean lecithin

Commercial soybean lecithin is a complex mixture containing ca. 65–75% phospholipids together with triglycerides and smaller amounts of other substances. The major phospholipids include phosphatidylcholine, phosphatidylethanolamine and inositol-containing phosphatides. Other substances reported include carbohydrates, pigments, sterols and sterol glycosides. This paper reviews the nature of the compounds found in soybean lecithin and our present knowledge of its composition.