The flavor substances changes in Fuliang green tea during storage monitoring by GC-MS and GC-IMS

Jiyuan Xu; Ying Zhang; Changbao Hu; Bo Yu; Cuixiang Wan; Bin Chen; Lirong Lu; Liren Yuan; Zhihua Wu; Hongbing Chen

doi:10.1016/j.fochx.2023.101047

The flavor substances changes in Fuliang green tea during storage monitoring by GC-MS and GC-IMS

Food Chem X. 2023 Dec 11:21:101047. doi: 10.1016/j.fochx.2023.101047. eCollection 2024 Mar 30.

Authors

Jiyuan Xu^{1

2}, Ying Zhang^{1

2}, Changbao Hu^{1

2}, Bo Yu^{1

3}, Cuixiang Wan^{1

3}, Bin Chen⁴, Lirong Lu⁴, Liren Yuan⁴, Zhihua Wu^{1

3}, Hongbing Chen^{1

3}

Affiliations

¹ State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, PR China.
² College of Food Science and Technology, Nanchang University, Nanchang 330031, PR China.
³ Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, PR China.
⁴ Riantea Limited, Nanchang 330100, PR China.

Abstract

To study the effect of storage (for 0, 3, 6, and 12 months) on the flavor of green tea (GT), we monitored the volatile organic compounds (VOCs) in GT through gas chromatography (GC) combined with ion mobility spectrometry and headspace solid-phase micro extraction, GC-MS (mass spectrometry). Then, relative odor activity value (ROAV) was applied to analyze the aroma contribution of the VOCs. During storage, the polyphenol and caffeine contents gradually decreased from 22.38 % to 18.51 % and from 4.37 % to 3.74 %, respectively, and the total soluble sugar first increased and then decreased (from 4.89 % to 7.16 % and then 5.02 %). Although the total free amino acid contents showed a fluctuating trend, the content of cysteamine increased gradually. The contents of VOCs with positive contribution to GT aroma, including linalool, geraniol, nonanal, and 6-methyl-5-hepten-2-one, decreased. They also contributed less in the ROAV after storage. The ROAVs of nonanal, linalool, and geraniol decreased from 3.37 to 0.79, from 100 to 38.21, and from 2.98 to 1.8, respectively, after 12 months of storage. Principal component analysis can be used to identify the samples with different storage durations based on these data. Given the increase in amount of cysteamine and decrease in that of linalool oxide, oxidation may be not the only factor responsible for tea quality in storage.

Keywords: Flavor substances; Gas chromatography ion mobility spectrometry (GC-IMS); Head space-solid phase micro extraction gas chromatography mass spectrometry (HS-SPME-GC–MS); Relative odor activity value (ROAV); Storage duration.