EXTRACTION OPTIMIZATION OF PECTIN FROM FRESH CITRUS PEEL WITH RESPONSE SURFACE METHODOLOGY

This study aims at optimizing the extraction process parameters of natural pectin from citrus peel, a kind of waste resource in orange production industry, containing high content of pectin. Single factor test and surface response methodology were employed to optimize the values of temperature, time, ratio of solid and liquid, and pH in the pectin extraction. The result indicates that optimized values of extraction time, extraction temperature, pH, and ratio of solid and liquid are 1.5 h, 90 degrees C, 2, and 1: 35, respectively. The second degree polynomial equation for this surface response model could be expressed as follows: Yield rate (%) = 0.85 + 0.086 A + 0.06 B - 0.23 C - 0.08 AB + 0.012 AC - 0.045 BC - 0.22 A(2) - 0.028 B-2 - 0.081 C-2 The high model F value and low P value, which are 22.59 and 0.0002, respectively, indicate that this surface response model is highly significant.