Studies on Flavor Components in Soybean Part II

Ethanol (1:1) extract of defatted soybean flour was fractionated systematically and the resulting phonolic acid fraction was investigated. This fraction had strong phenol-like flavor and contained at least seven phenolic acids including syringic, vanillic, ferulic, gentisic, salicylic, p-coumaric, and p-hydroxybenzoic acids. The main component among these was syringic acid, which was isolated as 3, 5-dinitrobenzoate. In addition, two isomers of chlorogenic acids, presumably isochlorogenic and chloro-genic acids approximately in a ratio of 1:10, were found in this extract. These substances have sour, bitter and astringent flavors.