The effect of roasting on capsaicinoids, volatile compounds, and fatty acids in Capsicum annuum L. (red pepper) seeds

Capsaicinoids, volatile compounds, and fatty acids were analyzed in red pepper seeds to determine any changes at different roasting temperatures. The contents of capsaicin and dihydrocapsaicin decreased as roasting temperatures increased. 3-Ethyl-2,5-dimethylpyrazine, 2,3,5,6-tetramethylpyrazine, 2-methoxy-3-(2-methylpropyl)pyrazine, 1-methylpyrrole, hexanedial, benzeneacetaldehyde, 2-acetylfuran, and butane-2,3-diol were newly detected in red pepper seeds roasted at 100 °C. Concentrations of pyrazines, pyrroles, oxygen-containing heterocyclic compounds, carbonyls, and alcohols increased rapidly in red pepper seeds as the roasting temperature increased. Such compounds could contribute roasted, grilled, and sweet odor notes to roasted red pepper seeds. Linoleic acid was the predominant fatty acid in all red pepper seeds. There were no significant differences in polyunsaturated fatty acids in red pepper seeds as roasting temperature increased. In conclusion, roasting red pepper seeds could be used in thermally processed foods because during roasting their pungency is reduced, desirable savory odors are enhanced, and the levels of polyunsaturated fatty acids remain unchanged.