Monitoring of Leaching Conditions for Functional Components of Black Tea Using Response Surface Methodology

Abstract

This study was conducted to predict optimum leaching conditions for functional components of black tea. Two variables were used to determine the optimum leaching temperature and leaching time with a five-level central composite design and response surface methodology. Soluble solid, reducing sugar, total phenolics, and total flavonoid contents increased as leaching temperature and time increased. The ranges of maximum leaching conditions for these components were 78.28～87.08 o C and 3.97～4.27 min. Vitamin C level was maximal at 61.29 o C and 2.68 min. Electron donating ability showed the highest values at 68.30 o C and 0.54 min. Based upon the superimposed results, it was predicted that the optimal ranges of leaching conditions for some functional components from black tea were 63～79 o C for 1.5～2.1 min.