Widely targeted metabolomics analysis of white peony teas with different storage time and association with sensory attributes

Widely Targeted Metabolomics Analysis Reveals Great Changes in Nonvolatile Metabolites of Oolong Teas during Long-Term Storage

“…A similar decreasing tendency was also observed for tannins ( Figure 5 a) such as proanthocyanidins and theaflavins components (TFs), which included theaflavins, theaflagallin, theaflavin-3'-gallate, theaflavin-3-gallate, theaflavin-3,3'-di-O –gallate, and theaflavin-3-O-(3-O-methyl) gallate-3-gallate. Theaflavins, as a typical oxidation product of flavan-3-ols, has a similar decreasing tendency during storage in white teas, black teas, and dark teas [ 10 , 27 , 28 ]. Zhao et al [ 29 ] suggested that long-term storage could enhance polyphenols' polymerization, while oxidative degradation or polymerization of TFs with other compounds could produce thearubigins (TRs) and theabrownines (TBs).…”

“…The umami matter of tea mainly comprises amino acids and derivatives and nucleotides and derivatives, including proteinaceous amino acids such as glutamine acid, serine, proline, and special nonproteinaceous amino acids such as theanine and γ-aminobutyric acid (GABA) [ 10 ]. In the present study, most proteinaceous amino acids ( Figure 5 a), including serine, proline, glutamine, lysine, leucine, tyrosine, and nucleotides and derivatives such as 6-methylmercaptopurine, cytosine, uracil, and deoxyadenosine, reduced as storage age increased.…”

“…Alkaloids, fatty acids, organic acids, and all other chemicals are all important for forming the complex and charming taste of tea. Alkaloids in tea infusion present bitterness, while fatty acids elucidate an aged and slightly sweet taste, and organic acids are usually sour [ 9 , 10 , 27 ]. In this study, many alkaloids ( Figure 5 a) such as N-Acetyl-5-hydroxytryptamine, betanin, indole, and tryptamine declined with stored time, while the main purine alkaloids, caffeine and theobromine, showed no significant change, and theophylline ( Figure 5 b) was detected at its highest level at 7 y samples.…”

“…It is recognized that taste is a crucial quality index of Camellia teas [ 8 ], which is directly affected by the chemical composition of compounds such as catechins, flavonoids, amino acids, tannins, purine alkaloids, and others, and their contents and proportions [ 9 ]. With an increasing application of metabolomics in food science, many compounds in food can be accurately quantified [ 10 ]. Similarly, metabolomics was exploited to identify the tea cultivar, origin, processing, grade information, etc., in tea research [ 1 , 11 , 12 , 13 ].…”

Transcriptomic and Metabolomic Profiling Reveals the Effect of LED Light Quality on Fruit Ripening and Anthocyanin Accumulation in Cabernet Sauvignon Grape

“…WGCNA has been used in numerous species to elucidate the interaction between physiological traits and gene expression ( 37 , 43 ). WGCNA was used herein to evaluate transcript expression and trait changes under different light quality treatments, and two modules, namely darkred and cyan, which were highly correlated with anthocyanins and sugars, respectively, were screened out.…”