FATTY-ACID COMPOSITION AND QUALITY DATA FOR OILS RICH IN GLA

Abstract

Following the paper presented at the ISF-JOCS World Congress in Tokyo in 1988, we intend in this paper to give some new data on the fatty acid composition and the quality of some plant-oils rich in gammalinolenic acid (GLA) : Borage, Evening Primrose and Blackcurrant oils. At the present time no standards or regulations exist for these oils, at least at the European level. The data obtained, resulting from the analysis of several samples or virgin and refined pure oils available and marketed in France, include : their fatty acid composition and particularly the GLA, C18:2 n-6, and Stearidonic acid, C18:4 n-3 content; some quality criteria such as : FFA ; Peroxide and Carbonyle Values ; Specific Extinctions at 270 and 232 nm ; and their content in some undesirable impurities or foreign matters such as : residual hexane, traces heavy metals (Pb, Cd, As, Sn, Hg), aflatoxins and pesticides. For all these data, Standards allowing a better safety for the consumers are described and proposed. This study suggests that in many cases, a carefully processed refining, performed according to the rules of the art, allows a better control of the oil's quality.