Changes to secondary lipid oxidation products that form in oat groats, cut groats, and flakes were investigated as a function of initial moisture and storage temperature Sixteen secondary lipid oxidation products, consisting of n-aldehydes, enals, and dienals, were monitored by headspace-SPME-GC-MS/MS using a modified standard addition protocol. Results confirm that low initial moisture levels results in accelerated formation of the oxidation products at both ambient and elevated storage temperatures Addnl., relatively minor changes to the secondary lipid oxidation products were observed in the oat groats and cut groats when produced at the higher initial moisture levels.