Dynamic changes in flavonol glycosides during production of green, yellow, white, oolong and black teas from Camellia sinensis L. (cv. Fudingdabaicha)

Abstract

Summary Flavonol glycosides with low thresholds are important flavour substances in tea leaves. This study monitored the dynamic changes in flavonol glycosides during the production of different teas. The fresh leaves of cv. Fudingdabaicha with 15.77 mg g−1 of total flavonol glycosides (TFG) were respectively processed into green, yellow, white, oolong and black teas. A reduction of TFG was observed for different teas, amongst which black tea contained the lowest level of TFG (9.83 mg g−1), followed by oolong tea (11.96 mg g−1), while green, yellow and white teas contained similar levels of TFG (~13.70 mg g−1). Fixation was crucial to maintain the stability of flavonol glycosides due to its inactivation effect on enzymes at high temperature. Principal component analysis results indicated that flavonol glycosides were vulnerable to fermentation, and the stabilities of flavonol glycosides were related with aglycone and glycoside moiety.

Rapid screening of phenolic compounds in congou black tea ( Camellia sinensis ) during in vitro fermentation process using portable spectral analytical system coupled chemometrics

“…Likewise, SNV method used for the mathematical transformation of the log (1/R) spectra used for scattering effects correction and to remove slope variation. SNV preprocessed NIR spectroscopy data were fed into chemometrics algorithm for searching relevant variables and subsequent model building which can be seen in Figure 2 (Chen, Zhao, & Lin, 2009;Fang et al, 2019;Li, Chen, Zhao, & Wu, 2015).…”

“…Many studies has been reported previously with the advantages of tea such as a study on polysaccharides protective effect against hyperlipidemia (Chen, Sun, Dong, Shen, & Xu, ), inhibitory activity of tea polysaccharides (Li, Wang, Yuan, Pan, & Chen, ), anti‐hyperglycaemic effects (Lin et al, ) and role against hyperlipidemia (Mao et al, ), also effects the blood glucose level and glucose tolerance which performed on mice (Chen et al, ). The identified and unidentified metabolic changes in fermented black tea is indicative of the changes in the antioxidant properties (Dong et al, ; Kim et al, ) also the change in flavonols glycosides which considered important flavor substances during the various teas production was study by (Fang, Song, Xu, & Ye, ). The phenolic compounds and their metabolites present in tea significantly affect the sympathetic nervous system, postprandial insulin, and angiotensin I‐converting enzyme (Monteiro & Peluso, ).…”

Physicochemical properties and antioxidant activity of oil extracted from Assam tea seeds (Camellia sinensisvar.assamica) by supercritical CO2extraction

“…In recent years, leaves and flowers of tea plants ( Camellia sinensis L.) have received more attention as a natural material for production of health‐enhancing foods and beverages due to their several health benefits such as antioxidant, antitumor, antimicrobial, hypoglycemic, and immunomodulatory activities and also anti‐agent in cardiovascular disease (Fang, Song, Xu, & Ye, ; Pinto, ; Zhu, Huang, & Tu, ). Both tea flowers and tea leaves contain important phenolic compounds.…”

“…Both tea flowers and tea leaves contain important phenolic compounds. For instance, Fang et al () reported that tea leaves of Camellia sinensis L. (cv. Fudingdabaicha) had 15.77 mg/g of total flavonol glycosides as important flavor substances.…”

Analysis and modeling of major polyphenols during oxidation in production of black tea

“…In recent years, studies have been taken up on the changes in flavanol glycosides due to oxidation, other polymeric polyphenolic compounds like theabrownins. (Faang, Song, Xu, & Ye, ; Wang, Sarkanj, & Jurasovic, ). Duration, temperature, and relative humidity of air and oxygen availability in the air during fermentation are crucial factors responsible for formation of high levels of desired products (Obanda, Owuor, & Mangoka, ; Tang et al, ) and their effect on the formation and depletion of the oxidized compounds and their correlation with sensory quality has been the subject of many studies (Asil, Rabiei, & Ansari, ; Muthumani and Senthil Kumar, ; Obanda et al, ; Owuor, Obanda, Nyirenda, & Mandala, ; Tang et al, ).…”