Scientific Study

Monitoring oxidative flavor changes in almonds is only possible if the chemical and sensory profile during roasting and storage is first established. Herein almonds roasted at two different temperatures (115 and 152 °C) were stored at 39 °C for 0 to 12 months and were analyzed by Headspace Solid-phase Microextraction Gas Chromatography-Mass Spectrometry (HS-SPME-GC/MS), descriptive analysis and consumer hedonic analysis. Volatile profiles, descriptive sensory profiles and consumer hedonic scores were analyzed for predictive relationships. Descriptive attributes involving Roasted and Nutty, as well as consumer liking were highest in fresh almonds, while flavors typically associated with oxidative rancidity such as Cardboard, Painty/Solvent, Soapy, and Total Oxidized increased during storage. Compounds most important for predicting rancidity-related attributes were lipid oxidation products, including pentanal, hexanal, heptanal, and octanal. Consumer liking was best predicted by similar compounds to those predicting Clean Nutty flavor, including Maillard reaction products, such as 2- and 3-methylbutanal, 2-methylpyrazine and 2,5-dimethylpyrazine.