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Composition of fatty acids and structure of triglycerides in medium and low erucic acid rapeseed
Author(s) -
Zadernowski R.,
Sosulski F.
Publication year - 1979
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02674154
Subject(s) - erucic acid , rapeseed , degree of unsaturation , chemistry , fractionation , oleic acid , fatty acid , triglyceride , composition (language) , linoleic acid , polyunsaturated fatty acid , linolenic acid , food science , chromatography , biochemistry , organic chemistry , cholesterol , linguistics , philosophy
Total triglycerides in medium (MEAR) and low (LEAR) erucic acid cultivars of rapeseed were fractionated by argentation chromatography into twelve and ten fractions, respectively. Gas liquid chromatography of the fatty acids in the triglyceride fractions and their 2‐monoglycerides was used to evaluate the structural characteristics of the individual fractions. Fractionation occurred on the basis of degree of unsaturation, molecular weight and positional characteristics. The most mobile fractions contained 34–50% of saturated fatty acids while the less mobile had 59–65% of polyunsaturated fatty acids. In the medium erucic acid oil, long chain fatty acids (C20–C22) were found in all fractions, but four fractions of low erucic acid oil were essentially free of long chain acids. Two of these fractions in the latter oil, which represented 44% of the total triglycerides, were glycerol trioleate and dioleoyllinoleoylglycerol. The majority of the 2‐positions were occupied by unsaturated C18 fatty acids, generally in the order of linoleic ≥linolenic> oleic acids. The saturated and long chain fatty acids occurred predominantly in the 1‐and 3‐positions. The various fractions of medium and low erucic acid oils were similar in structural composition except that eicosenoic and erucic acids substituted for oleic acid in some external positions. Erucic acid did not appear to substitute directly for oleic acid in the 2‐position.