【作者】 廖晓珊；

【导师】 钟晓红； 曾虹燕；

【作者基本信息】 湖南农业大学 ， 果树学， 2010， 硕士

【摘要】 湘莲为睡莲科植物。莲的干燥成熟种子属于药食兼用型的中国特有资源,是一种高级滋补食品,可鲜食,也可当干果食用。湘莲还可以制作出许多美味佳肴湘莲具有多种保健与食疗作用。湘潭湘莲不仅栽培历史悠久,而且产量高,质量优良,驰名中外。论文研究了提取湘莲蛋白的最佳方法。本试验以湘莲为原料,研究了料液比、提取温度、提取时间对湘莲蛋白提取率的影响。通过单因素试验,确定了在料液比为1：12,盐浓度为0.15mol/LNaCl的条件下,45℃恒温提取湘莲粉50 min,蛋白质提取率为86.45%。采用Osborne分级制备得到四种湘莲蛋白组分,分别对其氨基酸组成进行了研究。结果表明,湘莲蛋白质中清蛋白的含量最高(41.58%),其次为球蛋白(26.58%),谷蛋白(18.0%),醇溶蛋白含量最低(6.0%)。氨基酸分析表明,四种蛋白组分中的必需氨基酸都高于或接近FAO/WHO推荐值。营养评价结果表明,清蛋白和球蛋白的BV、AAS值高于FAO/WHO氨基酸模式值。根据氨基酸评分(AAS)和化学评分(CS),湘莲蛋白第一限制性氨基酸为蛋氨酸+胱氨酸,必需氨基酸指数(EAAI)为57.95。DSC分析表明,湘莲清蛋白、球蛋白、谷蛋白和醇溶蛋白的变性温度分别为81.7、75.2、66.8和69.4℃,湘莲是一种优质植物蛋白质资源。以湘莲蛋白为原料,研究了木瓜蛋白酶水解湘莲蛋白质最佳条件。在单因素试验分析基础上,进行了正交试验。同时考虑到实际操作可行性,以水解度为指标,确定了木瓜蛋白酶水解湘莲蛋白质的最佳工艺条件：温度55℃,pH值5.5,酶添加量0.16g,底物浓度4%,反应时间30 min。采用水洗脱盐法对提取的湘莲蛋白进行脱盐处理。最佳脱盐水量为与沉淀物相当体积的水,水洗1次即可。湘莲蛋白粉的喷雾干燥制备法的最佳条件为：蛋白沉淀物在自然条件下发酵20 h,进料浓度为30%,进风温度为180℃,可得蛋白纯度高达87.5%的湘莲蛋白粉。通过红外图谱分析,蛋白粉中同时还含少量的糖类和脂类。更多还原

【Abstract】 Xiantan Lotus is a water lily plant. Dried lotus seeds are mature type of Chinese food, and it is used be a used specific resources with medicine function. Xiangtan lotus cultivation is not only a long history but also with high yield and good quality. Lotus itself is an advanced nourishing food,can be Edible in fresh. Dried fruit also can be consumed. Application of lotus seed can produce many seeds with a variety of delicious and therapeutic function of health.This paper studied the best way to extract lotus’seeds protein. We used lotus’ seeds as raw material and studied the liquid ratio, extraction temperature and the extraction time in extraction rate of lotus’seeds protein in the experiment. The optimal extraction was obtained as follows:the ratio of solid and liquid 1:12 (g/ml), extraction in 0.15mol/L NaCl solution at 45℃for 50 min. The extraction yield was 86.45%.The four protein components of lotus seed were obtained by Osborne fractionation and their amino acid contents was analyzed. The results showed that content of albumin in the lotus seed protein was the highest (41.58 g/100 g), following by those of globulin(26.58 g/100 g), glutelin(18.00 g/100 g)and that of prolaminet was the lowest(6.00 g/100 g). The essential amino acids in the four protein components were less or higher than that in FAO/WHO reference pattern, respectively. The values of BV and AAS in the albumin and globulin were higher than that of the pattern. Based on amino acid score (AAS)and chemical score (CS), the first restrictive amino acids of the lotus seeds protein were methionine and essential amino acid, and its essential amino acid index(EAAI) was 57.95. DSC results showed that the denaturation temperatures of albumin, globulin, glutelin and prolamin were 81.7、75.2、66.8 and 69.4℃, respectively. The protein of lotus seed is a superior resource of plant proteins.With lotus seeds’protein as raw material, the test studied optimal extraction was obtained as follows:temperature 55℃, pH 5.5, enzyme 0.16g, substrate concentration 4%, reaction time 30min.In this test, used washing desalination method to except the salt which contained in lotus seed’protein. The optimal washing method was as fowllows: use the water volume as the same as the protein volume, and then washed once just enough. The Lotus seed protein powder spray drying method of the optimum conditions is:ferment in the natural condition 20h, feed concentration 30%, inlet temperature 180℃. Through the method we could got protein purity of 87.5% of lotus protein powder. IR spectra analysis shows that Protein powder also contains small amounts of carbohydrates and lipids.更多还原