OPTIMIZATION OF COMBINED PECTINEX AND VISCOZYME APPLICATION FOR POLYPHENOL EXTRACTION IN GRAPEFRUIT PEELS

This study examined the application of simultaneous treatment of grapefruit peels with Pectinex SP-L and Viscozyme L preparations to enhance the extraction yield of polyphenols from grapefruit peels. First, the impact of the temperature treatment, pH values of solutions, ratio of Pectinex to Viscozyme concentration, total concentration of both enzyme preparations and time treatment on the extraction yield of polyphenols from grapefruit peels was 50°C, 4.8, 5:2, 1.5% and 50 min, respectively. The response surface methodology was then used to optimize the treatment conditions for maximizing the extraction yield of phenolic compounds. When the total concentration of both preparations and the treatment time in the combined Pectinex SP-L and Viscozyme L treatment were 1.8% v/w and of 54 min, respectively, the extraction yield reached maximum (81.2%). This value was 25.7% and 46.8% higher than that in the only Pectinex SP-L treatment and Viscozyme L treatment, respectively. In addition, the time treatment in combined Pectinex SP-L and Viscozyme L were 14.3 and 47.6% lower than those of the only Pectinex SP-L treatment and the Viscozyme treatment.