Combining gas chromatography-ion mobility spectrometry and olfactory analysis to reveal the effect of filled-N2 anaerobic treatment duration on variation in the volatile profiles of gabaron green tea
Dongzhu Huang, Mengru Li, Hong Wang, Maoyin Fu, Shaode Hu, Xiaochun Wan, Zhuochen Wang, Qi Chen
Abstract
Gamma-aminobutyric acid green tea (GAGT) is a tea with health benefits by a special anaerobic process to increase the GABA content. However, the effect of this special processing on tea flavor during processing has been rarely reported. In this study, GC-IMS was combined with principal component analysis (PCA) to clarify the effects of different times of anaerobic treatment on the volatile profiles in finished GAGT. GC-O-MS and quantitative descriptive analysis (QDA) were used to investigate the flavor characteristics of GAGT infusion. The results showed that the aroma abundance of GAGT peaked at about 8 h after anaerobic treatment, and then the GAGT flavor delayed. At this point, the differential compounds including nonanal, octanal, heptanal and linalool could be perceived by panalists. Other compounds that didn't change very much in content during processing but had high FD factors, such as β-damascenone, (E)-β-ionone, 1-octen-3-ol and 1-octen-3-one, were also screened as odor-active compounds. Together, they constitute the characteristic flavors of “sweet”, “ketchup” and “slightly fermented” of GAGT infusion. This study will help to better understand the mechanism of GAGT aroma generation and improve the processing.