Widely targeted metabolomic approach reveals dynamic changes in non-volatile and volatile metabolites of peanuts during roasting

Roasting influences the color, flavor, and antioxidant activities of peanuts. However, the biochemical mechanisms that occur during roasting are not well known. In this study, the dynamic changes in non-volatile and volatile metabolites in raw, light, and dark roasted peanuts were investigated using ultra-performance liquid chromatography with a widely targeted metabolomic approach based on tandem mass spectrometry and gas chromatography-mass spectrometry. A total of 738 non-volatile metabolites (comprising 12 subclasses) and 71 volatile metabolites (comprising 14 subclasses) were identified in raw and roasted peanuts. Significantly different non-volatile and volatile metabolites were detected. Among them, amino acids, sugars, and lipids (lysophosphatidylethanolamines and oxidized fatty acids) were found to be highly linked to flavor formation. In addition, the enhanced color and antioxidant activities of peanuts were attributed to the Maillard reaction and sugar degradation. These results provide comprehensive insights into the quality improvements of peanuts during roasting.