Abstract:

Deproteinized and destarched banana peel was taken as the raw material to extract pectin with HCl solution. Effects of pH of HCl solution, extraction temperature, extraction duration, solid/liquid ratio and salting-out temperature were on extraction yield of pectin were investigated by single factor test, and a mathematical model, describing pectin extraction, was established by means of Design Expert 7.0. According to the results of single factor test, the “optimal” pH of HCl solution, extraction temperature, extraction duration, solid/liquid ratio and salting-out temperature were 2.2, 85 ℃, 1.4 h, 1:3 and 70 ℃,
respectively. The mathematical model of pectin extraction was Y (%) ﹦－36.9+1.39X1+ 0.785X2－1.95X3+ 0.142X4－ 0.0192X1X2 － 0.0151X1X3 － 0.0198X1X4+ 0.0289X2X3 － 0.0004X2X4+ 0.0237X3X4+ 0.386X1 － 0.0045X2 － 0.696X3 － 0.0008X4, where Y was the extraction yield of pectin, and X1, X2, X3 and X4 were the pH of HCl solution, extraction temperature, extraction duration and salting-out temperature, respectively. Variance analysis for this equation showed that the interaction between extraction temperature and extraction time presented significant effect on the extraction yield of pectin.

Key words: pectin, extraction technology, mathematical model