The profile of dynamic changes in yellow tea quality and chemical composition during yellowing process

Processing, chemical signature and food industry applications of Camellia sinensis teas: An overview

“…There is also an increase in the levels of pipecolic acid, betaine, lysophosphatidylcholines and theasinensin B. Therefore, this combination of factors and metabolites is responsible for the significant changes in the color and flavor of this tea ( Wei et al, 2021 ).…”

Effect of Yellowing Duration on the Chemical Profile of Yellow Tea and the Associations with Sensory Traits

“…During “yellowing”, moisture-dependent thermochemical reactions occur, leading to the formation of yellow tea leaf color and unique flavor [ 5 ]. Specifically, tea leaves turn yellow and then the color is gradually deepened [ 6 ], accompanied by a decrease in bitterness and astringency whereas an increase in sweetness [ 5 ]. Polyphenols are the major bioactive and sensory quality-related components of yellow tea.…”

“…Moreover, the content of gallic acid in yellow tea is more than 10-fold greater than green tea, suggesting the important role of gallic acid in constructing the taste of yellow tea [ 1 , 5 ]. Wei et al [ 6 ] reported that the levels of most catechins, amino acids, phenolic acids and glycosyl derivatives of volatiles decreased significantly, whereas betaine, piperidine, theasinensin B and lysophosphatidylcholines increased significantly after 24 h of yellowing. Among these constituents, the contents of most amino acids and sucrose were positively related with the intensities of umami and sweetness, the contents of catechins and phenolic acids were positively correlated with the intensities of bitterness and astringency, while phaeophorbides had a positive correlation with red color of tea leaves [ 6 ].…”

“…Wei et al [ 6 ] reported that the levels of most catechins, amino acids, phenolic acids and glycosyl derivatives of volatiles decreased significantly, whereas betaine, piperidine, theasinensin B and lysophosphatidylcholines increased significantly after 24 h of yellowing. Among these constituents, the contents of most amino acids and sucrose were positively related with the intensities of umami and sweetness, the contents of catechins and phenolic acids were positively correlated with the intensities of bitterness and astringency, while phaeophorbides had a positive correlation with red color of tea leaves [ 6 ]. Moisture content, temperature, duration and ventilation frequency are the key factors affecting the chemical conversions in the yellowing process [ 9 ].…”

“…The chemical changes of yellow tea during the yellowing process have been investigated, mainly focusing on the non-volatile compounds related to taste [ 1 , 5 , 6 ]. Sensory flavor is a combination of taste and smell, which is related to the compositions of non-volatiles and volatile compounds, especially the volatiles involved in retronasal identification [ 10 ].…”