采用超声波辅助法从菠萝皮中提取果胶，分别对草酸铵浓度、固液比、沉析pH值和提取温度等4个影响果胶提取率的因素进行考察。依据单因素试验结果进行正交试验，通过 R和 K 值的比较，确定沉析pH值对果胶提取率的影响较大，并确定最佳试验条件：沉析pH值3.5，提取温度75℃，草酸铵浓度7g·L -1，固液比1∶30，果胶提取率可达到7.32％。红外分析结果显示，果胶在1051 cm-1处的吸收峰证明有乙酰基的存在，1620 cm-1、1749 cm -1处吸收峰的强弱对比表明菠萝皮提取果胶为低酯果胶。%In this paper ,pectin was extracted from pineapple peel using Ammonium oxalate method assisted by ultrasonic , four factors such as Ammonium oxalate concentration , precipitation agent pH value , extracting solid-liquid ratio and extraction temperature which effect on pectin extraction yield was investigated separately .Orthogonal test was utilized on the basis of results of single-factor test .Through comparing R and K value ,it could be concluded that precipitation agent pH value had great influence on pectin extraction yield .The best experiment scheme was reached that precipitation agent pH value was 3.5 ,Ammonium oxalate concentration 7 g · L-1 ,extraction temperature 75℃ and extracting solid-liquid ratio 1∶30 .The pectin exacting yield could reach 7.32% .FT-IR spectroscopy of pineapple rind pectin suggested that absorption peak on 1 051 cm-1 was caused by acetyl groups and peaks density contrast on 620 cm-1 and 1 749 cm-1 indicated that pineapple peel pectin was a low ester pectin .
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