Proteomic insights into lipid degradation and volatile compound changes during foxtail millet storage

Foxtail millet quality deteriorates during storage, but the mechanisms behind aging-related changes are not fully understood. This study investigated lipid degradation and volatile compound changes in stored foxtail millets, employing proteomics to uncover underlying quality decline mechanisms. After 30 days, fatty acid contents increased, accompanied by a general coarser grain surface texture. GC/MS analysis revealed decreased proportion of alcohol alongside elevated aldehyde, ketone, acid, and ester proportions. Proteomic analysis indicated shifts in key metabolic pathways, especially the upregulation of fatty acid degradation enzymes that likely drive accumulation of short-chain organic acids. These acids may promote hydrolysis of starch granules and surface proteins, leading to a looser and rougher grain microstructure. Moreover, changes in peroxisome-associated proteins suggest enhanced oxidative stress, which may facilitate the oxidation of unsaturated fatty acids into various volatile compounds. These combined alterations contribute to the observed decline in foxtail millet quality during storage.