Optimization of enzyme assisted extraction of total catechin from cashew nut (Anacardium occidentale L.) testa by Box-Behnken desgin (BBD) and Response surface methodology (RSM)

Abstract

In this study, enzyme-assisted extraction was performed to extract total catechin from the cashew nut testa. Response surface methodology, using Box-Behnken design was employed to optimize and investigate the effect of four independent variables: sample/solvent ratio (1/20 – 1/40 g/mL), enzyme concentration (1 – 3 % mL/g), extraction time (30 – 90 min) and extraction temperature (40 – 60oC) on the catechin content. The experimental data were fitted to a second order polynomial equation using multiple regression analysis with high coefficient of determination value (R2 = 0.9457). The model F-value of 14.92 with low p-value (p < 0.0001) indicated that the model was highly significant and could be employed to optimize the extraction process. Optimal extraction conditions for the total catechin content were determined as follows: sample/solvent ratio of 1/35.84 (g/mL), enzyme concentration of 2.45 (% mL/g), extraction time of 89.41 (min) and extraction temperature of 58.75 (oC). Under these conditions, the highest total catechin content was predicted to be 11.5 (mg CE/g dry basis), which was in good agreement with the experimental value of 11.1±0.45 (mg CE/g dry basis). Keywords: Cashew nut testa, total catechin content, Box-Behnken design, optimization, response surface methodology, enzyme-assisted extraction.