GC-IMS-Based Analysis of the Effect of Frying Temperature on Volatile Flavor Substances in Highland Barley Tsampa Flour

To clarify the effects of different frying temperatures and grain colors on volatile organic compounds (VOCs) in highland barley (HB) tsampa flour, gas chromatography-ion mobility spectrometry (GC-IMS) was used to analyze the VOCs in two types of HB with two colors, Goumangzi and Kunlun-15. The VOCs were analyzed at different frying temperatures (160, 180, 200, 220 and 240 ℃). The results showed that a total of 62 compounds was detected, among which 44 organic compounds could be accurately identified, including 19 aldehydes, 10 alcohols, 5 ketones, 5 esters, 4 pyrazines and 1 furan. Frying had a significant effect on the composition of VOCs in tsampa flour, with the increase of frying temperature, the total amount of alcohol VOCs tended to decrease gradually, while aldehydes, ketones, esters, pyrazines and furans VOCs tended to increase. Pyrazines, aldehydes and ketones were the characteristic and main flavor substances of HB tsampa flour, and frying at higher temperature (220, 240 ℃) was favorable to their production. The variation of VOCs with frying temperature was more significant in WHB, except for furan VOCs, the relative changes of other compounds were higher than those in BHB. The principal component analysis showed that there were significant differences in the flavor of BHB and WHB tsampa flour, which could be classified into two different flavor types. This study was expected to provide a theoretical basis for the development of technical specifications for the production of highland barley tsampa flour.