Abstract

Asian pear (Pyrus pyrifolia cv. Niitaka) peel, a by-product that results from juice processing, is a good source of arbutin, a polyphenol, which has a whitening effect on the skin. The objective of this study was to investigate the optimum extraction conditions for arbutin from Asian pear peel by supercritical fluid extraction (SFE) using response surface methodology (RSM) based on Box-Behnken experiment design. Arbutin was extracted using co-solvent, methanol and ethanol. A three-level four-factor Box-Behnken experiment design was performed to evaluate the combination effect of four independent variances, co-solvent concentration (22 to 30%), extraction pressure (250 to 300 bar), extraction temperature (30 to 60°C) and extraction time (30 to 60 min), coded for X1, X2, X3 and X4, respectively. The coefficients of determination (R2) of response surface regression equations were 0.89 (p<0.01) for methanol as a co-solvent and 0.84 (p<0.01) for ethanol. Arbutin content by SFE with methanol was the highest with 3.35 mg/g at 26%, 275 bar, 45°C and 45 min. In conclusion, arbutin from Asian pear peel would be extracted from the most efficiently combination of 26% methanol as co-solvent, extraction pressure of 275 bar, extraction temperature of 45°C and extraction time of 45 min in the SFE. 
 
Key words: Asian pear, arbutin, response surface methodology, supercritical fluid extraction, Box-Behnken experiment design.

Abbreviation

SFE, Supercritical fluid extraction; RSM, response surface methodology;PLA2, phospholipase A2; L-DOPA, L-3, 4-dihydroxyphenylalanine; HPLC, High-performance liquid chromatography; RSREG, response surface regression; SAS, statistical analysis system.