Lipid metabolic characteristics and marker compounds of ripened Pu-erh tea during pile fermentation revealed by LC-MS-based lipidomics. (15th March 2023)

• Record Type: Journal Article
• Authors: Li, Jia; Yuan, Haibo; Rong, Yuting; Qian, Michael C.; Liu, Fuqiao; Hua, Jinjie; Zhou, Qinghua; Deng, Yuliang; Zeng, Jun; Jiang, Yongwen
• Is Part Of: Food chemistry. Volume 404:Part B(2023)
• Publication Date: 2023-03-15
• Subjects: Ripened Pu-erh tea -- Lipidomics -- Microbial fermentation -- Phospholipid -- Free fatty acid -- Fatty acid ester of hydroxy fatty acid -- Liquid chromatography-mass spectrometry; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2022.134665
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: This is the first lipidomics study on pile fermentation of ripened Pu-erh tea (RPT) 485 lipids were detected in RPT and FAHFAs were detected for the first time in tea. Fermentation caused chlorophylls breakdown and prominent phospholipids degradation. Microbial fermentation caused enormous formation of FFA and FAHFA. FAHFAs were enriched from undetected level and could serve as marker compounds of RPT. Abstract: Ripened Pu-erh tea (RPT) is a unique microbial fermented tea. Herein, we investigated the lipid composition of RPT and its metabolic changes during pile fermentation, by nontargeted lipidomics profiling and quantitative analysis using liquid chromatography-mass spectrometry (LC-MS). A total of 485 individual lipid species covering 26 subclasses were detected, and fatty acid ester of hydroxy fatty acid (FAHFA) was detected in tea for the first time. Among them, 362 species were significantly altered during fermentation. Chlorophylls decomposition, phospholipids degradation (especially phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine), formation of free fatty acid (FFA) (especially FFA18:3, FFA18:2), and formation of FAHFA, were annotated as the key pathways. Particularly, FAHFAs were undetected in raw tea and gradually enriched to 227.0 ± 9.6 nmol/g after fermentation ( p < 0.001), which could serve as marker compounds of RPT associated with microbial fermentation. This study will advance understanding the lipid metabolic fate in microbial fermentation and its role in RPT quality. Chemical compounds studied in this article : Linolenic acid (PubChem CID: 5280934); Linoleic acid (PubChem CID: 5280450); Oleic acid (PubChem CID: 445639); PS(22:0/18:2) (PubChem CID: 52925820); PS(20:0/18:3) (PubChem CID: 52925629); Pheophytin a (PubChem CID: 135398712); Pheophorbide a (PubChem CID: 253193)