Nontargeted metabolomics predicts the storage duration of white teas with 8-C N-ethyl-2-pyrrolidinone-substituted flavan-3-ols as marker compounds. (November 2019)

• Record Type: Journal Article
• Authors: Xie, Dongchao; Dai, Weidong; Lu, Meiling; Tan, Junfeng; Zhang, Yue; Chen, Mei; Lin, Zhi
• Is Part Of: Food research international. Volume 125(2019)
• Publication Date: 2019-11
• Subjects: White tea -- Metabolomics -- Storage duration -- Absolute quantification -- EPSFs -- Prediction model; Epigallocatechin gallate (PubChem CID: 65064) -- Epigallocatechin (PubChem, CID: 72277) -- Epicatechin gallate (PubChem, CID: 107905) -- Epicatechin (PubChem CID: 72276) -- Catechin (PubChem CID: 9064) -- Theanine (PubChem, CID: 439378) -- 1-Ethyl-5-hydroxy-2-pyrrolidinone (PubChem, CID: 90921336) -- Pyroglutamic acid (PubChem CID: 7405) -- Theogallin (PubChem CID: 442988) -- Theobromine (PubChem CID: 5429); EPSFs 8-C N-ethyl-2-pyrrolidinone-substituted flavan-3-ols -- VIP variable importance in projection -- BHYZ Baihaoyinzhen -- BMD Baimudan -- SM Shoumei -- UHPLC−QTOF/MS ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry -- R-EGCG-cThea 5′′′R-Epigallocatechin gallate-8-C N-ethyl-2-pyrrolidinone -- S-EGCG-cThea 5′′′S-epigallocatechin gallate-8-C N-ethyl-2-pyrrolidinone -- UPLC−QQQ − MS ultra-performance liquid chromatography -triple quadrupole mass spectrometry -- PCA principal component analysis -- PLS-DA partial least squares discriminant analysis -- R-ECG-cThea 5′′′R-epicatechin gallate-8-C N-ethyl-2-pyrrolidinone -- R-EGC-cThea 5″R-epigallocatechin-8-C N-ethyl-2-pyrrolidinone -- S-EGC-cThea 5″S-epigallocatechin-8-C N-ethyl-2-pyrrolidinone -- R-EC-cThea 5″R-epicatechin-8-C N-ethyl-2-pyrrolidinone -- S-EC-cThea 5″S-epicatechin-8-C N-ethyl-2-pyrrolidinone -- EGCG Epigallocatechin gallate -- ECG epicatechin gallate -- EGC epigallocatechin -- C catechin -- EC epicatechin -- GCG gallocatechin gallate -- GC gallocatechin -- Val valine -- Trp tryptophan -- Asn asparagine -- Phe phenylalanine -- Ile isoleucine -- Leu leucine -- Pro proline; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2019.108635
• Languages: English
• ISSNs: 0963-9969

Abstract

Abstract: Storage has a dramatic influence on the chemical composition, sensory qualities, biological activity, and therefore the commercial value of white tea. In this study, the metabolites in white teas stored for 1, 3, 7, and ≥ 10 years were comprehensively compared by a nontargeted metabolomics investigation. Most metabolites, including catechins, flavonol/flavone glycosides, amino acids, nucleosides, organic acids, aroma precursors, lipids, and carbohydrates, decreased with increasing storage duration, while 8-C N-ethyl-2-pyrrolidinone-substituted flavan-3-ols (EPSFs) and pyroglutamic acid increased. The absolute quantifications of 24 storage-related compounds combined with linear regression analysis showed that a panel of 5 indexes based on EPSFs has a good predictive ability for the storage duration of white teas (correlation coefficients were 0.9294 and 0.8812 in the model and test sets, respectively). The errors between the predicted and the actual storage durations ranged from −1.75 to 1.84 years for the white teas stored for <10 years. Graphical abstract: Unlabelled Image Highlights: Metabolomics and absolute quantification were applied to study stored white teas. Contents of 104 metabolites in stored white teas were compared. 27 metabolites were identified as being primarily storage-related. EPSFs contents showed good predictive ability for the storage durations.