乙醇沉淀法提取柚皮果胶的工艺研究

[目的]优化乙醇沉淀法提取柚皮果胶的工艺。[方法]采用乙醇沉淀法提取柚皮果胶,探讨柚皮提取液浓缩程度、沉淀用乙醇的浓度和用量、沉淀时间、洗涤用乙醇的浓度和用量、洗涤次数对果胶沉淀得率及产率的影响。[结果]当柚皮浓缩液与原提取液体积比为2∶5时,果胶沉淀得率为75.56%,且产品的表观品质较好。沉淀用乙醇与柚皮提取液体积比以1∶2较合适,沉淀用乙醇浓度取80%。混合体系中果胶浓度为3.678 mg/ml,乙醇与水的体积百分含量分别为44.4%和55.6%。当沉淀时间为30 min时,果胶沉淀得率达98.55%。沉淀粗果胶洗涤1次即可,洗涤用乙醇浓度选40%,洗涤用乙醇与柚皮提取液体积比为1∶5。[结论]在该研究确定的工艺条件下,乙醇沉淀法提取的柚皮果胶的品质较好。

Study on the Extraction Technology of Pectin from Pomelo Peel by Using Alcohol Precipitation Method

[Objective] The aim of the research was to optimize the technology of extracting pectin from pomelo peel by using ethanol precipitation method.[Method] Pectin was extracted from pomelo peel by using ethanol precipitation method. The effects of the condensation degree of the extracting solution of pomelo peel,the concn.and dose of ethanol for precipitation,precipitation time,the concn.and dose of ethanol for washing and washing times on the yield and production rate of pectin precipitate were studied.[Result] When the volume ratio of the concentrated solution of pomelo peel to the original extracting liquid was 2∶5, the yield of pectin precipitate was 75.56% and the external qualities of products were better.The suitable volume ratio of ethanol to the extracting liquid of pomelo peel was 1∶2 and the concn.of ethanol for precipitation was 80%.The pectin concn.in the mixed system was 3.678 mg/ml and the volume percentage of ethanol and water were 44.4% and 55.6% resp.When the precipitation time was 30 min, the yield of pectin precipitate reached 98.55%.Crude pectin needed once washing for precipitation and the used ethanol concn.for washing was 40%.The volume ratio of ethanol for washing to the extracting liquid of pomelo peel was 1∶5.[Conclusion] Under the confirmed technology conditions in the research,the extracted pectin from pomelo peel by using ethanol precipitation method had better qualities.