Physical and Chemical Changes of Wenzhou Yellow Soup

Published: Wednesday 15 November, 2017

Chlorophyll is an unstable compound that is damaged by the reaction of oxidation, cleavage and substitution due to the action of heating in the manufacture of yellow tea, resulting in the reduction of green matter and the yellow matter more exposed, which is the main reason for yellowing of yellow tea . According to the determination of yellow tea in the manufacturing process, 60% of total chlorophyll is destroyed. The process of damage the fixation was the most,followed by the pile boring, the initial baking process.
During the process of fried system of Wenzhou yellow soup , the contents of carbohydrate and amino acids all have significant changes. The conversion of these substance plays an important role in the aroma and taste of yellow tea. Starch decreases with the frying process and some of it may be converted to soluble sugars. The total soluble sugar also showed a decreasing trend, but the amino acid content increased significantly. Amino acids are both an important part of the taste of tea and a precursor of the aroma. Under the action of heat, sugar and amino acids combines to form sugar amine compounds, which are involved in the composition of aromatic substance in tea. Yellow tea through heating, volatile aldehyde content increases, constitute an important component of the aroma of yellow tea. Under the action of heat, the low-boiling aromatic substance are volatilized to reveal the fragrant substance with good aroma, which are also the reasons for the formation of the aroma of Wenzhou yellow soup.