【作者】 王晶；

【导师】 孔??；

【作者基本信息】 东北农业大学 ， 食品科学， 2007， 硕士

【摘要】 玉米蛋白粉是玉米湿法生产淀粉的副产物，它含有60％以上的蛋白质。由于玉米蛋白水溶性差，且赖氨酸和色氨酸含量较低，限制了它在食品工业中的应用。目前，玉米蛋白大部分是作为动物饲料或当作“三废”直接排放，极大地浪费了蛋白质资源并对环境造成污染。通过酶法水解，可以提高玉米蛋白的水溶性，并且水解产物具有许多生理活性，有利于深层次开发玉米蛋白，提高玉米资源的利用率。本课题主要研究了制备具有强抗氧化性玉米蛋白水解物的最佳水解条件、玉米蛋白水解物的分离纯化、氨基酸组成及其在生、熟肉糜中对脂肪氧化的抑制作用。采用单因素试验，以对卵磷脂脂质氧化体系的抑制作用和水解物的还原能力为指标，确定了碱性蛋白酶Alcalase水解玉米蛋白粉制备水解物的最佳条件为：底物浓度10％，酶与底物蛋白比为1.0％，水解时间5h。通过测定不同水解时间水解物的水解度，考察了水解度与水解物的抗氧化活性间的关系。得出并不是水解度越大，水解物的抗氧化活性越强，本试验得出当DH=26.49％时，水解物的抗氧化活性最强。采用G-25凝胶过滤层析法对玉米蛋白水解物进行分离纯化并测定分子量。结果表明：水解物中肽的分布是连续的，分子量在147～1745Da间的小肽的抗氧化效果很强。添加1.0％、1.5％、2.0％的玉米蛋白水解物于生肉糜中，在冷藏过程中测定肉糜的红度值、TBARS值、pH值、MetMb百分含量，并对感官指标进行评定。结果表明：与对照组相比，添加水解物的处理组在7d内能显著抑制脂肪的氧化，增加肉糜鲜红的色泽，且添加量越大效果越好。为了进行比较，将未水解的玉米蛋白(添加量2.0％)和BHA(添加量0.02％)添加到肉糜中，结果表明添加水解物的处理组对脂肪氧化的抑制效果要好于添加玉米蛋白的处理组，但不如添加BHA处理组的好。同时感官评定也获得了相同的结果。将1.0％、1.5％、2.0％玉米蛋白水解物添加到熟肉糜中，在冷藏过程中测定肉糜的红度值、TBARS值、pH值、并对感官指标进行评定。结果发现：添加水解物的处理组对熟肉糜的脂肪氧化也有一定的抑制作用，感官评定也获得了相同的结果。更多还原

【Abstract】 Corn gluten meal is a byproduct of the com wet-milling process and contains more than 60%protein. The major drawback of using corn gluten meal in food industry is that it is very insoluble inwater and the contents of Lys and Trp is low. Currently, the main use of corn gluten meal is as ananimal feed or it is discharged as wastes, which is a great mass of waste and pollution forenvironment. Enzymatic hydrolysis has been used to increase the solubility of corn gluten meal andthe hydrolysates have a lot of physiological activity, which profit the development of corn glutenmeal and increase the utilization of corn resource.The main objective here was to study the optimum hydrolysis condition of preparing comprotein hydrolysates with high antioxidative activity, separation and purification of corn proteinhydrolysates, the composition of amino acid and the inhibitory effects on lipid oxidation in raw andcooked pork patties.The optimum hydrolysis conditions of preparing hydrolysates with high antioxidative activityby Alcalase alkaline protease hydrolyzing corn gluten meal was determined by adopting the singlefactor experiments, with the index of inhibiting oxidative capacity in liposome-oxidizing systemand reducing power of the hydrolysates: Temperature 50℃, pH value 9.0, substrate concentration10%, ratio of enzyme to substrate 1.0% and time of hydrolysis 5h.The relationship between the degree of hydrolysis (DH) and antioxidative activity wasevaluated by determining DH of the hydrolysates with different hydrolysis time. The antioxidativeactivity of the hydrolysates did not become strong with DH increasing. When the DH was 26.49%,the antioxidant activity of the hydrolysates was strongest.The corn protein hydrolysates at a 1.0%、1.5%、2.0% concentration level were added to rawpork patties, During the storage period, a value, TBARS, pH value, metMb(%) were measuredand sensory evaluation was performed on raw pork patties. The results showed that the treatmentsadded hydrolysates had significant inhibitory effects on lipid oxidation and kept the red color ofpatties in 7 days, when compared with controls. The inhibitory effect enhanced as the adding levelof the hydrolysates increased. Nonhydrolyzed corn gluten meal (2.0% adding level) and BHA(0.02% adding level)were added to raw patties in order to make a comparison, the conclusion wasthat the treatments with hydrolysates had higher inhibitory effects on lipid oxidation thannonhydrolyzed corn gluten meal, but they were inferior to BHA. The same results were got by sensory evaluation.The hydrolysates at a 1.0%、1.5%、2.0% concentration level were added to cooked pork patties,during the storage period, a value, TBARS, pH value, were measured and sensory evaluation wasperformed on cooked pork patties. The results showed that the treatments added hydrolysates hadsignificant inhibitory effects on lipid oxidation and the same results were got by sensory evaluation.更多还原