Characterization of Aroma‐Active Compounds in Microwave Blanched Peanuts

Microwave blanching of peanuts has been explored as an alternative to conventional oven methods based on its speed of operation, energy savings, and efficiency of process control. Although processing times can be greatly reduced, the occurrence of stale/floral and ashy off‐flavors has been reported at high process temperatures. This study examined the chemical compounds responsible for this off‐flavor using solvent extraction/solvent assisted flavor evaporation (SAFE), gas chromatography‐olfactometry (GC/O), gas chromatography‐mass spectrometry (GC/MS), and aroma extract dilution analysis (AEDA). Select compounds were quantified based on AEDA results using SAFE and GC/MS. Quantification, threshold testing, and analysis of model systems revealed increased formation of guaiacol and phenylacetaldehyde in the off‐flavored peanuts, which resulted in the burnt and stale/floral flavors noted by a trained panel.