Subject: Food Technology
Peroxide values [PV], free fatty acid values [FFAs], conjugated dienes [CD], tocopherols, headspace volatiles and consumer hedonic response were measured in light roast [LR] and dark roast [DR] almonds stored under conditions that promote rancidity development over 12 months. Results demonstrate that although rancidity develops at different rates in LR and DR almonds, consumer liking was not significantly different between these almonds. Average hedonic ratings fell below 5 ("neither like nor dislike") by 6 months of storage. This did not correspond with recommended industry rejection standards of PV <5 mEq and FFA <1.5 % oleic. FFAs remain well below <1.5% oleic during storage indicating that FFAs are not a good marker of rancidity in roasted almonds stored in low humidity environments. Regression of consumer liking to rancidity indicators revealed that select headspace volatiles including: heptanal, octanal, nonanal, 2-octenal, 2-heptanone, 2-pentylfuran, hexanal, and pentanal, correlate better with liking than non-volatile indicators.