Study On Characteristics Of Extraction Of Super-micro-comminuted & Enzyme-assistant Black Tea

The static and dynamic extracts and extract kinetics of black tea are systematically studied by technology of enzyme and super-micro-comminution. The major conclusions are as follows:1. The quality of tea drink is compared by four treatment methods. The quality by super-micro-comminuted tea powder adding enzymes extracting was superior, which by super-micro-comminuted tea powder posterior, which by common tea powder adding enzymes posterior again, and which by common tea powder inferior.2. The experimental parameter was optimized by Response Surface Experiments. The results demonstrated that, the extract quality of black tea mainly depended on temperature, time, quantity of adding enzymes and their interactions, the maximal soluble solids contents of common tea powder extraction were 2.54° Brix when quantity of adding enzymes 12 u L, time 60min, temperature 60℃, which of super-micro-comminuted tea powder extraction were 3.59° Brix when quantity of adding enzymes 12 μ L, time 80min, temperature 60℃, and the maximal tea polyphenols contents of common tea powder extraction were 4.06g/L when quantity of adding enzymes 12 μ L, time 80min, temperature 60 ℃, which of super-micro-comminuted tea powder extraction were 5.58g/L when quantity of adding enzymes 4 μ L, time 40min, temperature 50℃.3. It was proven predominant for Super-micro-Comminuted Enzymatic Reactor (SCER) to extract black tea. The soluble solids contents and tea polyphenols contents of tea drink by SCER , showed a up trend when cutting temperature, cutting frequency, cutting time and enzyme quantity increased, which are 6.7~12.6%, 1.5~8.0% higher than by colloid mill, 16.0~20.1% and 6.2~ 24.4% higher than by hot water extracting directly, respectively. The tea polyphenols contents greatly increased 23.3~35.6% (above 40Hz) when adding enzymes compared with not adding enzymes in the reactor.4. The soluble solid dissolving out of black tea mainly depended on inner diffusion. The kinetics of extraction of the soluble solid contents from common tea powder and super-micro-comminuted tea powder agreed with the first order steady state model. The first order rate constant of the super-micro-comminuted tea powder became larger when the extraction temperature increased, which was 1.27-2.22 times as large as that of common tea powder at the same situation. The kinetics of enzymatic reaction is fit to Michaelis-Menten equation.