Influence of stir-frying on the lipid stability and flavor substances in oat flour during storage using HS-SPME-GC-MS and electronic nose

Abstract

We used stir-fried oat flour as experimental material and raw oat flour as a control to explore the influence of stir-frying on the storage quality of oat flour. The HS-SPME-GC-MS method combined with the electronic nose technology was used to understand the lipid stability and analyze the changes in the flavor of the substances during the entire storage period. It was observed that during the storage period, stir-fried oat flour contained less water than raw oat. The former was characterized by a lower fatty acid value, lower acid value, and lower linoleic acid content, but higher oleic acid content and palmitic acid content compared to the latter. With the passage of storage time, the palmitic acid content significantly increased, and the linoleic acid content significantly decreased in raw and stir-fried oats flour (P <0.05). The sulfur and methyl contents in the stir-fried oat flour were higher than that in the raw flour, while the nitrogen oxide content in the former was lower than that in the latter. Stir-fried oat flour possessed a total of 78 identified flavor substances. The process of stir-frying boosts the oxidation decomposition of unsaturated fatty acids aldehydes and heterocyclic compounds produced by Maillard reaction, so that the flavor substances of stir-fried oat flour is richer. Stir-fried oat flour, containing diverse types of flavor substances, experienced more obvious flavor changes throughout the storage period than raw oat flour.