[Breakdown of linoeic acid hydroperoxydes. Formation of volatile carbonyl compounds (author's transl)].

Linoleic acid hydroperoxydes (LOOH) containing 13-hydroperoxyoctadeca-9,11-(75%) and 9-hydroperoxyoctadeca-10,12-dienoic acid (25%) were emulsified at pH 6.5. After addition of hemoglobin, ferrous ions, ferric ions, cysteine or ascorbic acid the emulsions were stored 19 hours at 22 degrees C. The decrease in the diene and peroxyde concentrations and the formation of volatile carbonyl compounds were analysed. Ferrous ions and ascorbic acid were the strongest producers of volatile carbonyl compounds. In the presence of 10(-3) Mol ascorbic acid 6 mumol volatile aldehydes arise from 75 mumol LOOH. Hexanal (70 mol-%) was the main component of the aldehyde fraction. For plant foodstuffs the significance of the reaction of fatty acids hydroperoxydes with ascorbic acid for the formation of flavour substances is discussed.