1. Impact of harvest season on bioactive compounds, amino acids and in vitro antioxidant capacity of white tea through multivariate statistical analysis.
- Author
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Ma, Bingsong, Wang, Jiacai, Zhou, Binxing, Wang, Zihao, Huang, Youyi, Ma, Cunqiang, and Li, Xinghui
- Subjects
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MULTIVARIATE analysis , *OXIDANT status , *EPIGALLOCATECHIN gallate , *CATECHIN , *AMINO acids , *BIOACTIVE compounds , *HIGH performance liquid chromatography - Abstract
To explore the impact of harvest season in white tea, high-performance liquid chromatography (HPLC) and amino acid analyzer were developed for the determinations of 17 phenolic compounds, 3 purine alkaloids, 19 amino acids, γ-aminobutyric acid (GABA) and 4 main quality components in 18 Bai mudan sub-type of Xinyang white teas harvested in spring, summer and autumn seasons, respectively. Additionally, the in vitro antioxidant capacity was evaluated by 5 various assays. Principal component analysis (PCA), hierarchical cluster analysis (HCA) and partial least squares-discriminant analysis (PLS-DA) could completely classify these white teas by the harvest season, and indicated its profound impact on chemical composition in white tea. 14 Characteristic compounds (VIP ≥1.0), such as (−)-epigallocatechin (EGC), gallic acid, caffeine, l -theanine, conduced to identify the harvest season of white tea. Through comparison, the spring tea was observed to possess the highest amino acids, catechins contents and in vitro antioxidant capacity. (−)-Epicatechin (EC), EGC, (−)-epicatechin gallate (ECG) and (−)-epigallocatechin gallate (EGCG) were considered as the major antioxidants in white tea due to their highly significantly (p < 0.01) positive correlations. Overall, the research results provided support for the identification of harvest season in white tea. • Xinyang white teas were classified by harvest season through multivariate statistical analysis. • Spring and autumn teas possessed relatively higher amino acids, catechins and gallic acid. • 14 Characteristic compounds (VIP ≥1.0) conduced to identify the harvest season of white tea. • Spring tea had the highest antioxidant capacity of FRAP, ABTS, HSA and SSA. • EC, EGC, ECG and EGCG were confirmed as major antioxidants in the white tea. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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