The effects of different drying methods on the flavor profile of wheat germ using E-nose and GC-IMS

Abstract

The impact of hot-air drying (HA) and microwave-hot-air drying (MHA) on aroma components and free amino acids (FAAs) in wheat germ (WG) were investigated.It was found that drying treatment improved the rancidity odor of WG, and MHA is better than HA. A total of 56 volatile compounds were identified in WG following different treatments, with 20 compounds identified as key differential compounds, and 13 key compounds were further screened based on the relative odor activity value (ROAV) > 1. Compared with HA, MHA accelerated the conversion of alcohols to aldehydes in WG, resulting in a more intense aroma and enhanced freshness and sweetness, but with an increase in bitter amino acids. Glutamic acid (Glu) exhibited a negative correlation with five aroma substances, while lysine (Lys) and arginine (Arg) were significantly negatively correlated with six and four aroma substances, respectively. The above results indicate that 2 types of drying have an impact on WG flavours, these findings offer valuable insights for the development and utilization of wheat germ, providing a reference for further exploration in this field.