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.