龙眼果干蛋白组成及不同组份特性比较  

Composition and Total Antioxidant Activity of Proteins from Dried Longan Fruit

作　　者：卜智斌[1] 徐玉娟[1] 唐道邦[1] 吴继军[1] 陈丽婷[1] 

机构地区：[1]广东省农业科学院蚕业与农产品加工研究所广东省农产品加工重点实验室,广东广州510610

出　　处：《热带作物学报》2014年第10期2002-2007,共6页Chinese Journal of Tropical Crops

基　　金：国家"十二五"科技支撑计划项目(No.2012BAD31B03);广东省科技计划项目(No.2011A080803011;No.2012B091000157;No.2012B040500058)

摘　　要：以龙眼果干为原料,利用碱溶酸沉法提取龙眼果干粗蛋白,并测定其等电点,研究不同等电点龙眼蛋白的含量及其氨基酸组成,配制人工胃液以模拟不同等电点龙眼蛋白的体内消化情况,测定等电点粗蛋白及其模拟体内消化液的总抗氧化能力。结果表明:龙眼蛋白提取过程中的最佳浸泡时间为2 h,其等电点为p H3.0、p H3.5、p H4.0、p H4.5、p H5.0,其中p I3.0、p I4.0、p I5.0组份蛋白含量分别占果肉总蛋白的12.69%、21.68%、17.12%,均含有16种氨基酸,其中7种为人体必需氨基酸;不同等电点组份蛋白及其消化液总抗氧化能力有所不同,p I5.0粗蛋白的总抗氧化能力为276.33 U/mg Protein,显著高于另外2组等电点蛋白,而粗蛋白消化液总抗氧化能力最高为p I4.0蛋白,达154.72 U/mg Protein。Alkali-so lution and acid-isolation methods were carried out to determination the isoelectric point of dried longan protein,to analyse the composition of different p I proteins from dried longan fruit,in vitro digestion of longan proteins in different p I was conducted in a simulated digestion environment and compared the total antioxidant activity of different p I protein and its digestive fluid.The results demonstrated that： the best extracting time for longan pulp static leaching was two hours; p H3.0,p H3.5,p H4.0,p H4.5,p H5.0 were the isoelectric points of dried longan fruit proteins,and the relative percentages of longan proteins in p I3.0,p I4.0,p I5.0component from total dried longan fruit protein was 12.69%,21.68% and 17.12% respectively,all including 16 amino acids with seven essential amino acids; Proteins and its digestive fluid in different p I had different total antioxidant capacity,and the p I5.0 component had the highest total antioxidant capacity,276.33 U/mg Protein,while the digestive fluid of the p I4.0 component had the highest total antioxidant capacity compared to the others.

关 键 词：龙眼干 等电点 氨基酸 体外模拟消化 抗氧化 

分 类 号：S667.2[农业科学—果树学]