摘要随着小麦利用率的提高,小麦不再仅仅作为主食被人们所利用,小麦的成分之一麦谷蛋白是多种优良生物活性肽的来源,对麦谷蛋白的研究有助于麦的高值化利用。本文以麦谷蛋白为原料,研究了超声-离子液体([BMIM]PF6)处理后麦谷蛋白的理化特性和酶解产物抗氧化活性的变化。以期为小麦的深加工利用提供理论和技术支撑。86830
以巯基和二硫键的变化为评价指标,通过单因素试验确定了超声-离子液体处理麦谷蛋白的条件为超声功率300 W,处理时间15 min。在此条件下,超声-离子液体处理后,麦谷蛋白的紫外光谱、荧光光谱、红外光谱均发生了明显变化,这些结果表明超声-离子液体处理改变了麦谷蛋白的分子结构,麦谷蛋白表面疏水性得到增加。体积排阻法分析表明:与未处理相比,超声-离子液体处理后麦谷蛋白酶解产物中低分子量产物明显增多,说明超声-离子液体处理有利于蛋白的酶解。抗氧化试验结果表明:超声-离子液体处理能够提高麦谷蛋白酶解产物的清除DPPH自由基能力、螯合Fe2+能力以及还原能力,对麦谷蛋白酶解产物的抗氧化活性具有一定的改善作用。
毕业论文关键词:麦谷蛋白;超声-离子液体处理;光谱分析;分子量分布;抗氧化活性
Abstract With the increase of the utilization rate of wheat, wheat is not only used as a staple food。 Glutenin as one of wheat components is the source of a variety of excellent bioactive peptides。 Study on glutenin contributes to efficient utilization of wheat。 In this paper, the changes of physicochemical properties of glutenin and antioxidant activities of its hydrolysate were studied after ultrasonic-ionic liquid (UIL) treatment。 This paper aimed to provide theoretical and technical support for the rational utilization of the wheat resources。
Taking changes of sulfhydryl and disulfide bonds as evaluation indexes, the treatment conditions of UIL for glutenin, which were obtained by single factor experiment, were 300 W of ultrasonic power and 15 min of treatment time。 Under these treatment conditions, obvious changes for glutenin in ultraviolet spectrum, fluorescence spectra and infrared spectra were found。 These results indicated that UIL treatment changed the molecular structure of glutenin, increasing its surface hydrophobicity。 Size exclusion chromatography (SEC) analysis showed that the hydrolysates of glutenin with low molecular weight (MW) increased significantly after UIL treatment, suggesting that UIL treatment was conducive to enzymatic hydrolysis of glutenin。 Results of antioxidant analysis investigated that UIL treatment improved the DPPH free radical scavenging activity, chelating ability of Fe2+ and reduction ability of hydrolysate from glutenin。 Thus, UIL treatment could be used to increase the antioxidant activity of glutenin hydrolysate。
Keywords: glutenin; ultrasonic-ionic liquid treatment; spectroscopic analysis; molecular weight distribution; antioxidant activity。
目 录
第一章 绪 论 1
1。1 麦谷蛋白 1
1。1。1 麦谷蛋白的概念 1
1。1。2 麦谷蛋白的氨基酸组成及分析 1
1。1。3 麦谷蛋白的研究现状 2
1。2 生物活性肽 3
1。2。1 生物活性肽的定义 3
1。2。2 生物活性肽的分类 4
1。2。3 生物活性肽的抗氧化机制 4
1。2。4 生物活性肽的制备 4
1。2。5 生物活性肽抗氧化能力的测定指标