DETECTABLE ODOR THRESHOLDS OF SELECTED LIPID OXIDATION COMPOUNDS AT VARIOUS TEMPERATURES IN A GELATIN MODEL SYSTEM

Abstract

ABSTRACT.This study was undertaken to determine detection thresholds of selected volatile organics known to be produced during the oxidation of food lipids. Gelatin was chosen to simulate a complex thermally‐sensitive food system. Stock solutions of pentanal, hexanal, t‐2‐hexenal, heptanal, t‐2‐octenal, and t,t,‐2,4‐decadienal were prepared using distilled water. A gelatin (3%) dispersion was prepared with distilled water, cooled (22C) then organic stock solutions were added to it at parts per billion (ppb) concentrations. A 16‐member panel was acquainted with the use of the sniffing apparatus with suprathreshold concentrations of the organics used in the study. Samples were presented in ascending order of concentration; judges indicated detectable point of specified stimulus. Odor characters are reported for these organics at each temperature. The detectable odor thresholds (DOT) were positively correlated with viscosity, and negatively correlated with temperature. DOT values ranged from 22 to 170 ppb. DOT values increased in the order of pentanal < hexanal < heptanal < t,t‐2,4‐decadienal < t‐2‐hexenal < t‐2‐octenal.