猪血球水解蛋白质的功能特性和抗氧化性

该研究以热处理后的猪血球冻干粉为原料,通过碱性蛋白酶酶解制备水解蛋白质,并对所制备的水解蛋白质的功能特性和体外抗氧化活性进行研究。结果表明,该水解蛋白质具有较好的溶解性、吸湿性和保湿性及一定的起泡性,较弱的乳化性和泡沫稳定性,相对分子质量主要分布在2 000~3 000。体外抗氧化研究表明,水解蛋白质能够有效地清除·OH、DPPH·,抑制脂质过氧化,同时具有较强的总抗氧化能力和金属螯合能力。     

水解蛋白灭火剂的研究

介绍以花生提取油脂后所剩花生饼为原料,经碱性条件水解处理,制得多肽液,再加入适量稳定剂、防腐剂后,成为一种具有较好灭火性能的消防材料。经专业人员测试,其发泡倍数为7．6,析液时间7min,灭火时间116s,抗烧时间14min。均符合国家标准。     

从角蛋白中提取水解蛋白的研究

用鸡毛和其它用蛋白为原料．经过水解制提水解蛋白。研究了影响水解反应的因素,给出了制备水解蛋白的最佳工艺条件,并用水解蛋白制备了蛋白泡沫灭火剂和水解蛋白饲料。     

功能保健型酸奶研发及抗氧化性研究进展

本文的主要研究对象为功能性酸奶的研发以及对功能保健型酸奶的抗氧化性进行讨论。酸奶主要通过嗜热链球菌、保加利亚乳杆菌、双歧杆菌、植物乳杆菌等将牛奶经过发酵而成的,酸奶中含有丰富的蛋白质、钙、维生素B12、维生素B6、维生素B1等营养物质。牛奶进过乳酸菌发酵后食用更有利于人体吸收营养成分,促进人体肠道蠕动,补充肠道有益菌群,调节肠道菌群的动态平衡等功能。而近几年对于酸奶功能性的研究越来越多,也出现了很多功能性好抗氧化活性高的酸奶,但市场上几乎没有此类酸奶,剖析其原因可能有：功能型酸奶其研发工艺尚未成熟;人们对功能性酸奶的认知模糊和对新功能型酸奶的保健性仍然有所顾虑。     

水解蛋白灭火剂的研究

介绍以花生提取油脂后所剩花生饼为原料，经碱性条件水解处理，制得多肽液，再加入适量稳定剂、防腐剂后，成为一种具有较好灭火性能的消防材料。经专业人员测试，其发泡倍数为7．6，析液时间7min，灭火时间116s，抗烧时间14min。均符合国家标准。     

水解蛋白作为酸洗缓蚀剂的缓蚀性能研究

以发酵工业废水为原料提出菌体,将其部分水解后,所得水解蛋白液作为酸洗缓蚀剂,采用失重法研究了它在盐酸、硫酸溶液中对钢、铝的缓蚀效率,认定其在盐酸、硫酸溶液中对钢有较好的缓蚀作用,以及同六次甲基四胺复配后良好的缓蚀协同作用。     

污水处理厂污泥水解蛋白液对平菇生长的影响

污水处理厂污泥含有丰富的蛋白质,但目前大部分没有进行很好地开发利用。本文利用污水处理厂脱水污泥经氢氧化钙水解后的蛋白液对平菇进行基施和喷施试验,测试其对平菇的菌丝生长、产量和生物学效率的影响。结果表明:污泥水解蛋白液能促进平菇菌丝的生长,可提前5~6天出菇;当基施施用量为100 m L/袋时,平菇的生物学效率达到109.3%,增产率可达到25.9%;喷施1000倍污泥水解蛋白液时,平菇的生物学效率达到105.6%,增产率可达到21.6%。     

油菜和荷花蜂花粉提取物的抗氧化性研究

采用超声法,分别以甲醇、水为溶剂提取油菜和荷花的蜂花粉活性成分,通过测定油菜和荷花蜂花粉的提取物对超氧阴离子自由基、羟基自由基的清除率及对脂质过氧化的抑制率,评价两种蜂花粉的抗氧化能力。结果表明:两种蜂花粉提取物均具有较强的抗氧化作用,油菜蜂花粉提取物比荷花蜂花粉提取物有更强的抗氧化性。油菜蜂花粉甲醇提取物对超氧阴离子自由基、羟基阴离子自由基清除率可达到83.2%,99.2%,对脂质过氧化的抑制率可达到92.2%。将蜂花粉抗氧化提取物分为甲醇部、水部溶剂萃取物,经抗氧化活性比较,其强弱顺序为甲醇部>水部。     

姜中姜辣素和黄酮的提取及抗氧化性研究

利用不同方法从干姜中提取姜辣素和黄酮,测定其含量及抗氧化能力。结果表明,超声法优于纤维素酶法提取姜辣素,超声提取姜辣素的含量和纯度为2.1 mg/g、33.7%,DPPH、ABTS抗氧化IC₅₀分别0.187 mg/mL、0.227 mg/mL,FRAP值为1.16;微波法优于超声法提取黄酮,微波法提取的黄酮含量和纯度为1.14 mg/g、31%,DPPH、ABTS抗氧化IC₅₀分别0.185 mg/mL、0.215 mg/mL,FRAP值为1.29。由结果可知,干姜中姜辣素的含量高于黄酮,姜辣素和黄酮都具有抗氧化能力,但黄酮的抗氧化活性稍高于姜辣素。     

垂盆草提取液对小鼠免疫和抗氧化功能的研究

目的研究垂盆草提取液对实验性急性肝损伤小鼠免疫和抗氧化功能的影响。方法通过注射环磷酰胺(CP)抑制小鼠的免疫细胞,达到降低淋巴细胞增殖水平和网状内皮系统的吞噬功能,观察药物对小鼠免疫功能的调节作用;给小鼠注射D-半乳糖(D-gal),造成实验性急性肝损伤模型,测定血清及肝脏中超氧化物歧化酶(SOD)活力和丙二醛(MDA)浓度,观察垂盆草提取液对小鼠抗氧化能力的影响。结果垂盆草提取液能明显促进免疫抑制状态小鼠的淋巴细胞增殖及网状内皮系统的吞噬功能,垂盆草提取液对D-gal所致小鼠急性肝损伤模型具有提高SOD活性和降低MDA浓度的作用。结论垂盆草提取液对免疫功能低下的小鼠具有增强作用,同时能提高实验性肝损伤小鼠的抗氧化能力。     

Effect of Peptide Size on Antioxidant Properties of African Yam Bean Seed (Sphenostylis stenocarpa) Protein Hydrolysate Fractions

Enzymatic hydrolysate of African yam bean seed protein isolate was prepared by treatment with alcalase. The hydrolysate was further fractionated into peptide sizes of <1, 1-3, 3-5 and 5-10 kDa using membrane ultrafiltration. The protein hydrolysate (APH) and its membrane ultrafiltration fractions were assayed for in vitro antioxidant activities. The <1 kDa peptides exhibited significantly better (p < 0.05) ferric reducing power, diphenyl-1-picryhydradzyl (DPPH) and hydroxyl radical scavenging activities when compared to peptide fractions of higher molecular weights. The high activity of <1 kDa peptides in these antioxidant assay systems may be related to the high levels of total hydrophobic and aromatic amino acids. In comparison to glutathione (GSH), the APH and its membrane fractions had significantly higher (p < 0.05) ability to chelate metal ions. In contrast, GSH had significantly greater (p < 0.05) ferric reducing power and free radical scavenging activities than APH and its membrane fractions. The APH and its membrane fractions effectively inhibited lipid peroxidation, results that were concentration dependent. The activity of APH and its membrane fractions against linoleic acid oxidation was higher when compared to that of GSH but lower than that of butylated hydroxyl toluene (BHT). The results show potential use of APH and its membrane fractions as antioxidants in the management of oxidative stress-related metabolic disorders and in the prevention of lipid oxidation in food products.     

Ultrasonic-Assisted Enzymolysis to Improve the Antioxidant Activities of Peanut (Arachin conarachin L.) Antioxidant Hydrolysate

The objective of this work is to provide a theoretical basis for preparing peanut antioxidant hydrolysate in order to improve its antioxidant activities. Therefore, response surface methodology (RSM) based on the Box-Behnken design was used to optimize ultrasonic-assisted enzymolysis for the purpose of preparing peanut antioxidant hydrolysate. Results indicated that the DPPH free radical scavenging activity of peanut hydrolysate could reach 90.06% under the following optimum conditions: ultrasonic power of 150.0 w, reaction temperature of 62.0 °C, incubation time of 25.0 min, and initial pH value of 8.5. The DPPH free radical scavenging rate of peanut hydrolysate from ultrasonic-assisted enzymolysis improved comparing with that of peanut hydrolysate from protease hydrolysis alone. The peanut antioxidant hydrolysate was found to display eight improved kinds of antioxidant activities. In conclusion, the optimal ultrasonic-assisted enzymolysis technology conditions described in this paper, appear to be beneficial for preparing peanut antioxidant hydrolysate.     

Functional properties of protein extracted from flaked,defatted, whole corn by ethanol/alkali during sequential extraction processing

Functional properties (solubility, foaming capacity and stability, emulsifying capacity, emulsion stability, heat coagulability, heat gelation and film formation) of protein extracted by 45% ethanol/55% 0.1 M NaOH from flaked, defatted, undergermed corn during the Sequential Extraction Process (SEP) were evaluated and compared with those of a laboratory-prepared soy protein concentrate. SEP is a new approach to corn fractionation that recycles the ethanol produced from the fermentation of cornstarch to unstream steps of protein extraction and the simultaneous extraction of corn oil and dehydration of the ethanol. Freeze-dried corn protein extracts contained at least 80% crude protein (dry basis), which is indicative of protein concentrates. SEP protein concentrates had solubilities in water of greater than 80% at pH values of 7 or above and were significantly more soluble than the soy protein concentrate at pH above 3. SEP corn proteins also showed better heat stabilities and greater emulsifying capacities and emulsion stabilities. Dilute dispersions (0.1%) of corn protein produced substantial but less stable foams. Corn proteins produced films similar to zein and soy protein films but were unable to form heat-induced gels. These results indicate that SEP produces a protein concentrate with functional properties suitable for food and industrial uses. Paper presented at the session on New Processes: Extractions and Purifications II, 83rd Annual Meeting of the AOCS, Toronto, May 10–14, 1992.     

Partially hydrolyzed rapeseed protein isolates with improved functional properties

Limited rapeseed protein hydrolysates ranging from 3.1 to 7.7% hydrolysis were produced from isoelectric-precipitated protein isolate. Water absorption, oil absorption, whippability, foam capacity and stability, emulsifying activity, and emulsion stability of the hydrolysates were determined. All protein hydrolysates showed better functional properties than the original protein isolate. Foam and emulsion stability decreased as the degree of hydrolysis increased. The hydrolysate with the lowest degree of hydrolysis showed the best functional properties. These improved functional properties make rapeseed protein hydrolysates a useful product to be used in foods such as breads, cakes, ice creams, meat products, desserts, and salad dressings.