Abstract:

Camellia sinensis seed powder was extracted with hot water to obtain bioactive compounds with reducing power and three extraction parameters including liquid/material ratio, length of extraction time and extraction temperature were optimized using central composite design and response surface methodology based on single factor investigations for achieving maximum reducing power (reflected by 700 nm absorbance of the reaction system). A mathematical quadratic polynomial regression equation reflecting the relationship between extract reducing power and the above extraction parameters was set up. The optimal extraction parameters were found as follows: liquid/material ratio (mL/g) 16:1; extraction temperature 81 ℃; and length of extraction time 1.6 h. Under the optimized conditions, the actual 700 nm absorbance of reducing power was 0.616 ± 0.005, close to the predicted value of 0.610.

Key words: Camellia sinensis seeds, antioxidation, reducing power, response surface methodology