Optimization of Extraction of Tannins from Banana Peel Using Response Surface Methodology

Response surface methodology (RSM) was employed to optimize the extraction conditions of tannins from banana peels. Based on the single-factor experiments, four independent variables including ethanol concentration, solid to liquid ratio, extraction time and extraction temperature were selected as affecting factors. According to central composite design (CCD) the four factor, five levels experiments were carried out with the tannin extraction yield as evaluation index. The results show that the optimized conditions are as follows: ethanol concentration of 75.44%, solid to liquid ratio of 1:35.34, extraction time of 7.94 h, extraction temperature of 62.85°C. Under the optimized conditions, the predicted tannin extraction yield reaches 58.55%, while the actual extraction yield is 57.42% with the relative error of 1.13%.