【作者】 王莉莉；

【导师】 潘道东；

【作者基本信息】 宁波大学 ， 食品科学， 2011， 硕士

【摘要】 鹅肉是一种低脂肪、低胆固醇、高蛋白的营养健康食品。盐溶蛋白质是肌肉蛋白质的主要成分。因此,研究鹅肉盐溶蛋白凝胶及其水解产物的功能特性,对鹅肉制品的加工过程及鹅肉高档产品的开发具有重要的理论指导意义。本论文主要研究了氯化钠、pH、热变温度、氯化钙及磷酸盐对鹅肉盐溶蛋白凝胶硬度和保水性的影响,通过响应面试验,分别建立了硬度和保水性回归模型,并分析了各因素对它们的影响及二者之间的关联性;此外,根据回归模型,研究了底物质量浓度、pH及水解温度对水解度及DPPH自由基清除率的影响;最后,利用超滤膜将盐溶蛋白水解产物分成分子量范围不同的组分,比较其功能特性,确定最佳组分的分子量范围。主要研究结果如下:一、鹅肉盐溶蛋白凝胶制备条件的优化。单因素试验结果表明,NaCl浓度、pH和热变温度是影响凝胶硬度和保水性的主要因素。根据响应面试验结果,获得较优凝胶制备条件是:NaCl浓度0.65mol/L,pH7.20,热变温度78℃。在此条件下,测得凝胶的硬度和保水性分别为88.05g、91.48%。二、添加剂对鹅肉盐溶蛋白凝胶的影响。选择常见的焦磷酸钠、六偏磷酸钠、三聚磷酸钠和氯化钙作为制备凝胶的添加剂。以凝胶硬度和保水性为指标,优化四种添加剂的添加量,得到复合磷酸盐的最优配比,其结果为:CaCl2浓度0.02mol/L,三种磷酸盐的添加量分别为0.21%、0.16%、0.11%,此时复合磷酸盐的配比为4:3:2。同时,扫描电镜试验结果表明这四种添加剂对凝胶超微结构的影响不同。最优条件下,凝胶超微结构致密、均匀、平滑。根据食品添加剂使用卫生标准,确定复合磷酸盐总的最佳添加量为0.3%。三、鹅肉盐溶蛋白水解条件的优化。本试验主要对影响DPPH自由基清除率及水解度的因素进行了选择和优化,试验表明最优的水解条件为:底物质量浓度240mg/5mL、水解温度48.5℃、pH7.80。在此条件下,测得水解度为20.35%,水解产物对DPPH自由基的清除率为74.01%,与模型的预测值基本相符。四、鹅肉盐溶蛋白水解产物功能特性研究。用超滤膜将水解产物分为>5kDa、3~5kDa、2~3kDa和<2kDa四种组分。分别测定它们亚铁还原能力、抑制ACE活性的能力及几种自由基的清除率,确定分子量范围2~3kDa组分的抗氧化能力较强,<2kDa组分抑制ACE活性的能力较强。可见,鹅肉盐溶蛋白水解产物成分复杂,其功能特性各异。根据消费者需求不同,可以生产具有不同功能的鹅肉深加工产品。更多还原

【Abstract】 Goose is a kind of nutrition and health food, which is low-fat, low cholesterol and high protein. The salt-soluble meat proteins (SSMP) are the most important parts of muscle. Therefore, it is necessary to study the goose salt soluble protein gels and its hydrolysis product features, which has important theoretical significance for the processing of goose and the development of goose high-end products.The effect of sodium chloride, pH, temperature, calcium chloride and phosphates on gel hardness and water-holding capacity (WHC) of goose salt soluble protein were studied in this paper. The regression models of gel hardness and retention were established by the response surface experiment to analyze the impact of various factors on them and the relationship between the two. Furthermore, the effect of substrate concentration, pH and temperature on DPPH radical scavenging rate and degree of hydrolysis were studied according to the regression model. Finally, the hydrolysis products of salt soluble protein were separated roughly into several molecular components by ultrafiltration membranes. The molecular weight range of components of better functional properties was determined by comparing the features of all components. The main results were as follows:1. The optimization of the prepared process of goose salt soluble protein gel. The single factor test showed that NaCl concentration, pH and temperature were the main factors on hardness and water holding capacity of gel. Based on the result of response surface, the optimum preparation conditions of the gel are NaCl (0.65mol/L), pH (7.20 ) and temperature (78℃). In the optimum conditions, the gel hardness and water-holding capacity were 88.05g and 91.48%, respectively.2. Additives on the goose salt soluble protein gel. Tetrasodium pyrophosphate (TSPP), sodium tripolyphosphate (STPP), sodium hexametaphosphate (SHMP) and calcium chloride were selected to add into the preparation of goose salt soluble protein gel. Using the gel hardness and water retention as indicators, the addition of the four additives was optimized and the optimum ratio of compound phosphate was obtained, the results are CaCl2 (0.02mol/L), TSPP (0.21%), SHMP (0.16%), STPP (0.11%) and the ratio of compound phosphate was 4:3:2. At the same time, the scanning electron microscopy (SEM) results showed that the four additives have different degrees of impact on the ultrastructure of gels. The ultrastructure of gels at optimum conditions is more dense, uniform and smooth. The optimal addition of compound phosphate was identified as 0.3% according to the Hygiene Standards of Food Additives. 3. The optimization of hydrolysis of goose salt soluble protein. The effect of several process parameters: substrate concentration, pH and temperature on the DPPH radical scavenging rate and degree of hydrolysis were examined. Results showed that the optimum extraction conditions are 240mg/5mL substrate concentration, 7.80 of pH value and 48.5℃of temperature. In the optimum conditions, the DPPH radical scavenging rate and degree of hydrolysis were 74.01% and 20.35% respectively, that are basically correspond to model prediction value.4. The functional properties of hydrolysis products for goose salt soluble protein. The hydrolysis products were divided into four components (>5kDa, 3~5kDa, 2~3kDa and <2kDa) with ultrafiltration membranes and they were measured in iron reduction capacity, the ability to inhibit the ACE activity and free radical scavenging. Results showed that the component at the molecular weight range of 2~3kDa has strong antioxidant capacity and the component of <2kDa has strong ability to inhibit the ACE activity. Thus, it is easy to see that the compositions of goose salt soluble protein hydrolysates are multiple, and its functional properties are different. According to the different needs for consumers, the deep processing products of goose can be produced with different functions.更多还原