【作者】 陈英；

【导师】 周惠明；

【作者基本信息】 江南大学 ， 粮食、油脂及植物蛋白工程， 2010， 硕士

【摘要】 脱脂麦胚酶解粉已经实现了工业化生产,迫切需要进一步了解脱脂麦胚酶解粉的组成、理化性质以及活性功能。本文从组成成分、氨基酸组成、理化性质以及抗氧化活性和降血压活性五个方面,研究了脱脂麦胚酶解粉的功能活性,并与大豆肽、玉米肽和小麦蛋白肽进行了比较。脱脂麦胚酶解粉的水分含量为10.52%,以干基含量计,灰分含量为7.78%,蛋白质含量为47.42%,多肽含量为35.71%,淀粉含量为6.86%,粗纤维含量4.86%,其余糖份含量33.77%,砷和铅未检出。脱脂麦胚酶解粉的蛋白质含量低于大豆多肽(蛋白含量均在90%以上),玉米肽和小麦蛋白肽(蛋白含量在80%以上)。脱脂麦胚酶解粉必需氨基酸含量为32.57%,略微低于玉米肽(37.81%)和大豆肽(33.70%);赖氨酸和亮氨酸相对缺乏。脱脂麦胚酶解粉相对分子质量小于2000Da的组分占95%以上,相对分子质量范围1000Da-2000Da组成占10.05%,相对分子质量范围180Da-1000Da比例为66.77%,分子量小于180Da的比例为19.10%。pH 2-10范围内脱脂麦胚酶解粉氮溶解指数范围为64%-71%;脱脂麦胚酶解粉的吸油率为1.71mL/g;吸湿性和保湿性良好;浓度小于10%时,脱脂麦胚酶解粉具有良好的流动性。在体外抗氧化体系中,脱脂麦胚酶解粉的还原能力和清除DPPH自由基能力都高于大豆肽、玉米肽和小麦蛋白肽,DPPH自由基清除率为50%时脱脂麦胚酶解粉的浓度即IC50为1.36mgdw /mL;浓度为1.00mgdw/mL时,脱脂麦胚酶解粉螯合亚铁离子的百分率达到40%;和大豆肽、玉米肽和小麦蛋白肽一样,脱脂麦胚酶解粉也能较好地抑制亚油酸自氧化;胃蛋白酶和胰蛋白酶对脱脂麦胚酶解粉的抗氧化活性影响不大;在体内,脱脂麦胚酶解粉能显著提高D-半乳糖衰老模型小鼠血浆中T-AOC、GSH-Px的活力和SOD的活力(P<0.01),以及心脏中SOD的活力和T-AOC(P<0.01),能显著提高脑和肝脏中GSH-Px的活力(P<0.05)和脑中T-AOC(P<0.05),同时使血浆和各组织中的MDA含量显著降低(P<0.05)。故脱脂麦胚酶解粉有较好的体外抗氧化活性,同时能改善D-半乳糖衰老模型小鼠的氧化程度。脱脂麦胚酶解粉的体外ACE半抑制浓度IC50为1.04mgdw/mL;胃蛋白酶和胰蛋白酶对脱脂麦胚酶解粉的抑制ACE活性影响不大;一次性给予自发性高血压大鼠(SHRs)灌胃脱脂麦胚酶解粉,7小时后灌胃1000mg/KgWB脱脂麦胚酶解粉剂量组尾动脉收缩压相比0小时时下降将近20mmHg(P<0.05);连续灌胃500mg/KgWB脱脂麦胚酶解粉一个月后,SHRs血压从212.4±1.4 mmHg下降到184.4±17.1 mmHg,与高血压模型鼠相比显著下降(P<0.05)。故脱脂麦胚酶解粉在体外能抑制ACE,同时体内能降低原发性高血压大鼠的血压。更多还原

【Abstract】 Defatted wheat germ hydrolysatess(DWGH) was producted in the factory, then it was imperative for us to know about the composition, physical property, nutritive peculiarity, and active functions of DWGH. Compared to soybean-peptides, corn- peptide and wheat protein peptide, composition, physical property and nutritive peculiarity as well as antioxidant and hypotensive activities were objectively evaluated.DWGH was equally composed of 10% moisture contents, for dry basis, 7.78 ash content, 47.42% protein content, 35.71% peptide content, 6.86% starch content, 4.86% dietary fiber , 33.77 polysaccharide content, As and Pb were not also checked. However, the protein of soybean-peptides were all above 90%, the corn-peptide and wheat protain were all above 80%, which were higher than DWGH’s.The content of essential amino acid of DWGH reached 32.5%, which was less lower than corn-peptide(37.81%) and soybean-peptides(33.7%); Lysine and Leucine were lack in DWGH. The percent of relative molecular weight under 1000Da in DWGH was above 95%, and relative molecular weight between 1000Da and 2000Da took up 10.05%, the proportion of molecular weight between 180Da and 1000Da reached 66.77%, The one under 180Da was up to 19.1%.During pH 2-10, the nitrogen soluble index of DWGH was at range of 64%-71%; Oil-absorbing capacity of DWGH was 1.71ml/g; Moisture regain and moisture retaining quality was well; Below the concentration of 10%, the viscosity of DWGH was well. In vitro antioxidant assays, antioxidant activity of DWGH are best of all with respect to reducing power activity and DPPH radical scavenging activity,especially, IC50 of DPPH radical scavenging is 1.36mgdw/ml; At the concentration of 1.00mg/ml, chelating-ferrous activity of DWGH is about 40%; DWGH had good effect on inhibiting auto-oxidation of linoleic acid, which was similar with soy-bean peptides, corn-peptide and wheat protein peptide. The antioxidant activities were free of digestive enzymes. In vivo assay, DWGH significantly enhanced T-AOC and the activities of GSH-Px and SOD increased (p<0.01) significantly in the serum, increased the activities of SOD and T-AOC in heart (p<0.01) and the activity of GSH-Px in brain and liver also increased (P<0.05), meanwhile the activity of SOD in brain (P<0.05), futhermore reduced the contents of MDA in the serum and organs (P<0.05) in D-galactose-treated. So not only the DWGH is an efficient antioxidant in vitro, but also it might at least in part defer the aging process in mice induced by D-galactose.ACE inhibitory activity IC50 of DWGH was 1.04mgdw/mL, and digestive enzymes were not affected on the ACE inhibitory activity; Spontaneously hypertensivera rat(SHR) were each given 1000mg/Kg BW of DWGH by single gastrie intubation, the systolic blood pressure of rats were decreased significantly once time, 7 hour after lavaging, comparing with 0 hour, the decrease of the SBP of Captopril and 1000mg/Kg BW were respectively 12 mmHg and 20mmHg,was, which significant (P<0.05); Meanwhile, So SHRs were given DWGH at the doge of 500mg/Kg BW after one month, the systolic blood pressure of rats were decreased from 212.4±1.4 mmHg to 184.4±17.1 mmHg,which significantly changed compared with SHRs. So DWGH can inhibit ACE in vitro and decreased the systolic blood pressure of SHR in vivo.更多还原