Volatile Compound Profiles of Raw and Roasted Peanut Seeds of the Runner and Virginia Market-types

Abstract

The unique flavor of peanuts that develops during roasting is the primary driving force for the consumption of peanut products. Although rarely consumed raw, the raw state of the peanut contains the precursors involved in the transformations that lead to the distinct flavor development in roasted peanuts. Volatile compounds extracted from the headspace above raw and roasted peanut samples of the runner and virginia market types by solid phase microextraction were characterized using two-dimensional gas chromatography coupled with time-of-flight mass spectrometry. The roasting treatment and peanut market-type each had a significant impact on the types and concentrations of small molecular weight compounds found. Among 361 sample components detected, 290 compounds were found to be significantly different between the raw and roasted treatments (p < 0.05). The roasted samples contained pyrazines, pyrroles, thiazoles, and furans. Alcohols were the primary compounds found in the raw peanut samples. Additionally, 107 compounds were found to differ significantly between roasted runner and virginia-type peanuts. Virginia-type peanuts contained higher levels of linoleic acid oxidation products, such as 2-octenal, hexanal, and 1-octen-3-one. More significant distinctions in volatile compounds were recognized between runner and virginia market types than previously observed. In total, this study reported 119 volatile compounds that have not previously been reported in roasted peanuts, including 11 furans, seven pyrroles, five pyridines, and 12 pyrazines.