Chemical aspects of thermal damage to the nutritive value of vegetable oils. I.—Formation of intrapolymeric glycerides during heat polymerization of linseed and soya‐bean oils

Abstract

Abstract Observations on the nutritionally deleterious effects of heat‐polymerized vegetable oils and various fractions of them prompted an examination of the chemical nature of the products of polymerization. Analytical data for linseed and soya‐bean oils and for stand oils prepared from them are reported. The data suggest that linolenic acid reacts in a selective manner during thermal polymerization of linseed oil until the concentration of linolenic acid is greatly reduced. The relationship between content of polymeric acyl radicals and mean molecular weights of heated linseed and soya‐bean oils is discussed in connexion with the existence of intrapolymers. The refractive indices of heated linseed and soya‐bean oils bear a linear relationship to their content of dimeric acyl radicals. This provides a simple method of polymerizing to a desired content of dimeric acids.