超声辅助草酸铵法提取南瓜果胶及其理化性质研究

Ultrasound-assisted Extraction of Pumpkin Pectin by Ammonium Oxalate and Its Physicochemical Properties

以籽用南瓜废弃果肉为原料,将超声法的“空化”作用与草酸铵法的“螯合”作用相结合,优化提取果胶工艺。通过单因素试验确定了各影响因子(草酸铵浓度、料液比、提取时间和提取温度)的数据范围,并揭示了正交试验最优条件下果胶的理化特性。结果表明,各因素对提取率有不同程度的作用,提取温度80℃,草酸铵浓度0.8%,料液比1∶30,提取时间60 min,果胶平均得率为6.09%。该方法提取的果胶具有GB 25533-2010中的果胶凝胶特征,与QB 2484-2000标准和《食品化学法典》的要求一致,酯化度为75.23,属高甲氧基果胶。

The extraction process of pectin is optimized by combining the“cavitation”effect of ultrasonic method with the“chelation”effect of ammonium oxalate method taking the discarded pumpkin pulp for seed as the raw material.The data range of each influencing factor(concentration of ammonium oxalate,ratio of solid to liquid,extraction time and extraction temperature)is determined by single factor test,and the physicochemical properties of pectin under optimal conditions of orthogonal test are revealed.The results show that the extraction temperature is 80℃,the concentration of ammonium oxalate is 0.8%,the ratio of solid to liquid is 1∶30,the extraction time is 60 min,the average yield of pectin is 6.09%.The pectin extracted by this method has the characteristics of pectin gel in GB 25533-2010,which is consistent with the requirements of QB 2484-2000 standard and Food Chemicals Codex,the esterification degree is 75.23,which belongs to high high-methoxyl pectin.