【作者】 施树；

【导师】 赵国华；

【作者基本信息】 西南大学 ， 食品科学， 2008， 硕士

【摘要】 胡麻是我国重要的大宗油料作物,其中富含多不饱和脂肪酸和木酚素等多种功能成分。胡麻粕是一种优质的蛋白质资源。本论文以宁夏产胡麻籽为原料,经过脱胶脱油处理后,制备出实验室用胡麻粉,再采用碱溶酸沉法从其中提取胡麻分离蛋白,并确定了实验室提取的胡麻分离蛋白的最佳工艺参数;在此工艺条件下,制备出实验用胡麻分离蛋白质,并对其理化性质和功能性质进行了研究。1、通过对胡麻籽及胡麻粉的组成成分进行分析,结果显示胡麻籽中粗蛋白含量为25.37%,脱胶脱脂后的胡麻籽粉粗蛋白含量更高达到45.1%。2、采用碱提酸沉法从胡麻籽粉中提取分离蛋白,在单因素试验分析的基础上,通过正交试验优化胡麻分离蛋白的最佳提取工艺参数,以蛋白质提取率为考察指标,分析得到最佳提取工艺为:脱胶脱脂胡麻粉过80目筛后,按料水比1:13加入水,调节碱提液pH值为9.5,在60℃温度下提取20min后再次调节pH值到9.5,继续提取40min后离心,收集离心液调节pH值到胡麻蛋白等电点4.4后过滤,收集沉淀物干燥即为胡麻分离蛋白。在此条件下,胡麻分离蛋白的提取率约为42%,蛋白质的纯度达89.37%。3、对所制备的胡麻分离蛋白进行氨基酸分析,显示其氨基酸种类较为齐全,必需氨基酸全面,含量丰富;对该胡麻分离蛋白进行氨基酸评分认为其具有较高的营养价值,是一种较优质的蛋白质。4、胡麻蛋白的等电点pI为4.4。通过SDS-PAGE分析,胡麻分离蛋白主要有3种亚基组成,其分子量分别为:24.4kDa,20.7kDa,12.1kDa。5、通过对胡麻分离蛋白的进行热变性(DSC)分析,得到其变性温度为107.3℃。6、分别对胡麻分离蛋白的溶解性、持水性、持油性、起泡性及泡沫稳定、乳化性及乳化稳定、粘度以及凝胶力学性质等功能性质进行了研究,测定了不同蛋白质浓度、pH值、离子强度以及蔗糖等因素对功能性质的影响。结果显示,胡麻分离蛋白具有良好的功能特性,在食品工业中将具有很大的应用前景。更多还原

【Abstract】 Flaxseed has received increasing attention as a major source of oilseed and a high quality protein, as well as abundant functional factors containingα-linolenoic acid and lignan. The purpose of this investigation was to evaluate protein properties of flaxseed in NingxXia. The flaxseed meal was prepared by demucilaged and defatted flaxseed. The flaxseed protein isolate (FPI) was extracted from flaxseed meal, alkaline extraction and acid precipitation was optimized. Further, the detail study of the physicochemical and functional properties of FPI and their relations to the stmcture and factors were conducted to expound.1, The basic compositions analysis results of flaxseed and flaxseed meal showed that the content of crude protein is 25.37% and 45.1% respectively.2, Use protein extraction rate as the index to investigate the optimal techniques extraction of flaxseed protein isolation by dint of alkali-extraction and acid-precipitation through mono-factor and orthogonal experiments, The results indicated that the optimal technical condition is 1:13 of solid-liquid ratio, alkali-extracting pH9.5,temperature 60°C, to adjust alkali extracting pH9.5 when the extraction time is 20min,and then go on extracting 40 min. acid-precipitating pH 4.4. In this condition, it is leading to 42% of the protein extraction rate and 89.37% of protein content in the product.3, The amino acid analysis of flaxseed protein isolate indicated that FPI contained all essential amino acids. It was considered to be an excellent protein for 53.49 of the amino acid sore.4,The isoelectnc point of FPI is 4.4. The SDS-PAGE analysis indicated that FPI has three subunits with molecular weights of 24.4kDa, 20.7kDa, 12.1kDa.5, The DSC curve indicated that the denaturation temperature of FPI is103.7°C.6, This paper explored the functional properties of FPI under different protein concentration, pH, ionic strength and sucrose. The results indicated it is well in the solubility, water absorption capacity, fat absorption capacity, emulsification capability and emulsification stability, foaming capability and foaming stability, gelling mechanical properties of FPI. Thus it will be biggish foreground for FPI to be used in food industry.更多还原