榛子蛋白物理改性方法及理化性质变化研究

发布时间：2018-06-11 14:45

  本文选题：榛子蛋白质 + 物理改性　； 参考：《沈阳农业大学》2017年硕士论文

【摘要】：我国榛子普遍为野生榛子,由人工采集得到,榛子在食品加工中的应用范围较小,只有少数榛子零食产品以及榛子提油。在榛子提取油脂这一方面,采用低温压榨法提取出油脂后,剩余大量榛子粕,通常作为饲料以及肥料处理。而在榛子粕中含有大量的蛋白质,这些蛋白质的性质由于低温处理,所以极少量变性。如果对这些榛子粕做加工处理,作为主料或者辅料应用在更多食品加工中,可以提高榛子蛋白在食品加工中的应用以及副产物的利用和经济价值,同时对我国蛋白资源的匮乏进行填补。为了解决这个问题,本研究利用低温压榨法提取油脂后的榛子粕作为原料,提取榛子蛋白,采用加热、超声波辐射、微波辐射三种物理改性方法,对榛子蛋白质进行物理改性,并采用响应面法优化改性工艺。使用傅里叶变换红外光谱仪(FTIR spectrum)测定改性榛子蛋白二级结构,分析不同的改性方法对榛子蛋白二级结构的影响。采用聚丙烯酰胺凝胶电泳(SDS-PAGE)测定改性榛子蛋白分子质量,分析不同的改性方法对榛子蛋白分子质量分布的影响。为榛子蛋白在食品加工中的应用做基础准备。本研究的主要结果如下:1.测得榛子粕中含有粗蛋白21.6%。用碱溶酸沉提取蛋白质,用正交试验法优化提取蛋白质条件得到提取榛子蛋白质的最佳工艺为:榛子粕→粉碎→过80目筛→脱脂→按1:10固液比称取榛子粕并调pH值至8.5→ 40℃反应60min →固液分离→上清液→调pH值至4.5 固液分离→水洗沉淀→调pH值至7 →纯化→干燥→粉碎→过80目筛→榛子分离蛋白。应用此工艺提取榛子粕中蛋白质,得到榛子可溶蛋白质溶解浓度为5.734g/L,计算得到榛子粕蛋白质提取率为16%,榛子蛋白质提取率为76%。2.以最大溶解率为指标的榛子蛋白质改性条件为:加热处理时间8min,加热温度设定为80℃;超声波处理时间15min,超声波处理功率为150W,温度为40℃;微波处理时间27s,微波功率设定为350W。采用上述优化出的最佳工艺条件对榛子蛋白进行改性处理,得到改性后榛子可溶蛋白含量为4.672g/L。通过计算得到以上述最佳改性工艺条件进行改性的榛子蛋白溶解率为9.34%。3.以榛子蛋白质溶解率为最优改性条件改性后榛子蛋白的各方面性质为:起泡性和起泡稳定性分别由原来的15%,15%提高到55%,40%。持水性由原来的2.6ml/g降低为2.4ml/g。乳化性及乳化稳定性分别由原来的1.468,1.349变为1.196,3.735。粘度由原来的0.32pa*s升高到0.62pa*s。
[Abstract]:Hazelnut in China is generally wild hazelnut which is obtained by hand. The application range of hazelnut in food processing is relatively small only a few hazelnut snack products and hazelnut extract oil. After extracting oil from hazelnut by low temperature press, a large amount of hazelnut meal is usually treated as feed and fertilizer. There are a lot of proteins in hazelnut meal. The properties of these proteins are denatured very little because of low temperature treatment. If the hazelnut meal is processed and used as the main or supplementary material in more food processing, the application of hazelnut protein in food processing, as well as the utilization and economic value of by-products, can be improved. At the same time, the lack of protein resources in China was filled. In order to solve this problem, the hazelnut protein was extracted from hazelnut meal after oil extraction by low temperature pressing method, and three physical modification methods, heating, ultrasonic radiation and microwave radiation, were used to modify the protein of hazelnut. Response surface method was used to optimize the modification process. The secondary structure of modified hazelnut protein was determined by Fourier transform infrared spectroscopy (FTIR) and the effects of different modification methods on the secondary structure of hazelnut protein were analyzed. The molecular weight of modified hazelnut protein was determined by polyacrylamide gel electrophoresis (SDS-PAGE), and the effect of different modification methods on the molecular weight distribution of hazelnut protein was analyzed. Preparation for the application of hazelnut protein in food processing. The main results of this study are as follows: 1. The crude protein in hazelnut meal was 21. 6%. Protein was extracted by alkaline acid precipitation. The optimum conditions for extracting protein from hazelnut were optimized by orthogonal test. The optimum technology of extracting protein from hazelnut was as follows: the hazelnut meal was crushed by 80 mesh sieve and degreased by 80 mesh sieve, and the hazelnut meal was obtained according to the ratio of solid to liquid at 1:10 and the pH value was adjusted to 8. 5 鈩，

本文编号：2005635