果胶提取工艺数学模型的建立

运用Design Expert7.0 软件技术，采用响应曲面分析法，研究果胶提取影响因素对果胶提取得率的影响，建立果胶提取工艺数学模型。单因素试验结果表明，果胶提取得率最高的各影响因素值分别为：提取液pH2.2 左右，提取温度85℃，提取时间1.4h，液料比为3:1，盐析温度70℃。正交试验结果表明，提取液pH1.5、提取温度90℃、提取时间2.0h、盐析温度65℃、提取率最高为1.14%。果胶提取工艺数学模型为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。

Establishment of Mathematical Model of Pectin Extraction from Banana Peel

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.