Impact of harvest season on bioactive compounds, amino acids and in vitro antioxidant capacity of white tea through multivariate statistical analysis

• Published in: Food science & technology 2022-07, Vol.164, p.113655, Article 113655
• Main Authors: Ma, Bingsong, Wang, Jiacai, Zhou, Binxing, Wang, Zihao, Huang, Youyi, Ma, Cunqiang, Li, Xinghui
• Format: Article
• Language: English
• Subjects: Harvest season; l-theanine; Phenolic compounds; PLS-DA; White tea
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2022.113655

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