Flavour significant compounds in yeast autolysate Gistex X‐II powder. Part I. Acidic fraction

Abstract
Basic informations about the composition of yeast autolysate Gistex‐X‐II‐powder were obtained. The representative sample of volatile flavour‐significant compounds was isolated. There were 29 substances identified in the acidic fraction of the isolate and the odour of this fraction was organoleptically evaluated. The organoleptic properties were mainly influenced by the presence of lower fatty acids and phenylacetic and 3‐phenylpropionic acids. Two sulphur‐containing heterocyclic acids, i. e. 2‐thiophenecarboxylic and 5‐methyl‐2‐thiophenecarboxylic acids were identified for the first time as volatile constituents of foodstuffs. Flavour properties of these two and other 6 sulphur‐ and oxygen‐containing heterocyclic acids were evaluated and their mass spectra are presented.