【作者】 吴莹莹；

【导师】 杨铭铎；

【作者基本信息】 哈尔滨商业大学 ， 食品科学， 2011， 硕士

【摘要】 以小麦胚芽为原料,通过提取麦胚蛋白,蛋白酶水解,超滤提纯的方法制备小分子的麦胚多肽,对精制后的麦胚多肽的功能性、分子量分布,抗氧化活性,氨基酸组成进行了分析,并对麦胚多肽营养饮料的配方进行了研究。采用碱提酸沉的方法提取麦胚蛋白,通过单因素及正交分析,确定麦胚蛋白的最佳提取工艺为：pH值为10.00,提取温度为50℃,提取时间为90min,料液比为1：25,此时麦胚蛋白的提取率为78.70%。采用四种不同蛋白酶对麦胚蛋白分别进行单酶水解、双酶同步水解和分步水解,比较研究麦胚蛋白的酶解方法与水解物的DPPH·清除率的关系。结果表明：单酶水解时碱性蛋白酶的水解物DPPH·的清除率效果最好；双酶分步水解的效果优于双酶同步水解,其中先加碱性蛋白酶后加木瓜蛋白酶效果最好。采用3kDa和6kDa的超滤膜对麦胚多肽进行分级分离,考察了三种分离产物对DPPH·的清除能力,发现分子量在3kDa以下的麦胚多肽对DPPH·的清除率可达75.32%,高于其它分离产物。采用响应面试验方法对麦胚多肽的超滤条件进行优化试验,结果表明最佳超滤条件为：超滤压力0.08MPa,超滤时间41.37min,超滤pH为6.92,溶液浓度为2.00%,此时膜通量为4.85 L/(m2·h)对精制后的麦胚多肽进行体内及体外的抗氧化功能研究,发现麦胚多肽具有很好的清除自由基和抑制油脂氧化的能力,并能够提高亚急性衰老小鼠的抗氧化能力。通过对麦胚多肽氨基酸成分测定,确定了麦胚多肽所含有的氨基酸成分适宜人体吸收；采用正交分析和均匀分析的方法,确定麦胚多肽制备的营养饮料的配方为：麦胚多肽添加量5.00%,蜂蜜添加量1.75%,蔗糖添加量7.50%,柠檬酸添加量0.2%,乙基麦芽酚添加量0.003%,CMC添加量0.01%,黄原胶添加量0.06%,果胶添加量0.01%。更多还原

【Abstract】 In this study, small molecules of wheat germ peptide was extract by extracting protein of wheat germ, protease, ultrafiltration purification.The refined wheat germ peptide was analysis by functionality.molecular weight distribution, anti-oxidant activity,and acid composition. The nutrient beverage recipe of wheat germ peptide was also studiedUsing method by alkaline extraction and acid precipitation of wheat germ protein extraction, through the analysis of single factor and orthogonal to determine the optimum extraction of wheat germ protein was:pH was 10.00, extraction temperature was 50℃, extraction time was 90mins, solid to liquid ratio was 1:25, the best extraction rate of wheat germ protein was 78.70%.According to data defining the DH and the antioxidative activities,wheat germ peptides were prepared by singal- proteases hydrolyzed, mixed double- proteases hydrolyzed simultaneously and double- proteases hydrolyzed separately in steps. The results showed that the singal- proteases optimum hydrolytic condition for antioxidative activities was alcalase;double- proteases hydrolyzed separately in steps was better than mixed double-proteases hydrolyzed simultaneously, the optimum hydrolytic was added alcalase ealier than papain.The scavenging rate of Dpph of wheat germ peptide by ultra-filtration was separated by UF of 3kDa and 6kDa, the molecular weight was less than 3kDa had the best scavenging rate of Dpph,which was 75.32%.The optimal ultra-filtration parameters were determined by response surface analysis,the results show ultra-filtration pressure was 0.08Mpa, ultra-filtration time 41.37min, ultra-filtration pH was 6.92, ultra-filtration concentration was 2%,the flux was 4.85 L/(m2·h)The wheat germ peptide after refined was studied in vivo and in vitro antioxidant function,.The results show that wheat germ peptides have a very good free radical scavenging capacity, inhibition of lipid oxidation, and could improve the aging mice antioxidant capacity.By determined amino acids of wheat germ Peptide,measured the peptides of wheat germ contained the amino acid was suitable for the body to absorb.The optimmrecipe of wheat germ peptide nutrient beverage was developed from orthogonal experiment and uniform design experiment.The best recipe was peptide of wheat germ 5.00%, honeyl.75%, sucrose7.50, Citric acid0.2, Ethyl maltol 0.003%, CMC0.01%, xanthan gum0.06%, pectin0.01%.更多还原