FORMATION OF THE INTENSE FLAVOR COMPOUND TRANS-4,5-EPOXY-(E)-2-DECENAL IN THERMALLY TREATED FATS

Thermal degradation of several possible precursors of the intense flav or compound trans-4,5-epoxy-(E)-2-decenal in model experiments reveale d that the odorant is formed in significant yields from 13-hydroperoxy -9,11-octadecadienoic acid (13-HPOD) and 9-hydroperoxy-10,12-octadecad ienoic acid (9-HPOD). Of these hydroperoxides, arising in equal amount s during autoxidation of linoleic acid, the 9-HPOD was established as the more effective precursor. The key intermediates in the generation of the epoxyaldehyde were found to be 2,4-decadienal, arising from 9-H POD, and 12,13-epoxy-9-hydroperoxy-10-octadecenoic acid, a degradation product of 13-HPOD. Isolation and characterization of the precursors from a baking margarine confirmed glycerine-bound 9- and 13-HPOD as th e intermediates in the formation of the epoxyaldehyde during heating o f fats that contain linoleic acid.