大豆分离蛋白凝胶制备条件的响应曲面法优化研究

通过外界因子对大豆分离蛋白凝胶性影响的研究表明:大豆分离蛋白浓度、加热温度、加热时间是大豆分离蛋白凝胶性的显著影响因子.研究采用响应曲面法(RSM,Response surface methodology)对主要因子浓度、加热温度和加热时间进行了优化.研究表明应用该方法优化大豆分离蛋白凝胶制备条件是可行的,通过优化确定了大豆分离蛋白凝胶的制备条件为:大豆分离蛋白浓度16%,加热温度85℃,加热时间40 min.     

大豆分离蛋白浓度和温度对凝胶形成的影响

以大豆分离蛋白为原料,研究了蛋白浓度、温度、加热时间等因素对大豆分离蛋白凝胶形成的影响.结果显示,大豆分离蛋白形成凝胶的最佳条件是大豆分离蛋白水溶液浓度为16%,温度90℃,凝胶形成时间为23min,当温度在85℃～95℃之间,凝胶形成时间随大豆分离蛋白浓度变大而减少.在沸水中,由于气泡产生而无法形成凝胶.温度高于85℃会使凝胶颜色加深.     

pH和金属离子对大豆分离蛋白凝胶形成影响

在90℃,研究大豆分离蛋白浓度、pH值、金属离子、加热时间等因素对大豆分离蛋白凝胶形成影响。结果显示,酸性条件下大豆分离蛋白形成凝胶最适pH为3．0,碱性条件下形成凝胶最适pH为9．0,pH大于11在95℃水浴锅中加热5 min,大豆分离蛋白变为黄棕色粘稠状液体,且有异味;凝胶溶液中CaCl2浓度为0．4％时,形成凝胶透明性最高,时间为22min。     

pH和金属离子对大豆分离蛋白凝胶形成的影响

在90℃,研究了大豆分离蛋白浓度、pH值、金属离子、加热时间等因素对大豆分离蛋白凝胶形成的作用。结果显示,酸性条件下大豆分离蛋白形成凝胶的最适pH为3.0,碱性条件下形成凝胶的最适pH为9.0,pH大于11在95℃的水浴锅中加热5min,大豆分离蛋白变为黄棕色粘稠状液体,且有异味;凝胶溶液中CaCl2浓度为0.4%的时,形成凝胶的透明性最高,时间为22min。     

pH值和金属离子对大豆分离蛋白凝胶形成的影响

在90℃,研究了大豆分离蛋白浓度、pH值、金属离子、加热时间等因素对大豆分离蛋白凝胶形成的作用。结果显示,酸性条件下大豆分离蛋白形成凝胶的最适pH值为3.0,碱性条件下形成凝胶的最适pH值为9.0;凝胶溶液中CaCl2浓度为0.4%的时,形成凝胶的透明性最高,时间为22min。     

pH和金属离子对大豆分离蛋白凝胶形成的影响

在90℃，研究了大豆分离蛋白浓度、pH值、金属离子、加热时间等因素对大豆分离蛋白凝胶形成的作用。结果显示，酸性条件下大豆分离蛋白形成凝胶的最适pH为3．0，碱性条件下形成凝肢的最适pH为9．0,pH大于11在95℃的水浴锅中加热5min，大豆分离蛋白变为黄棕色粘稠状液体，且有异味；凝胶溶液中CaCl2浓度为0．4％时，形成凝胶的透明性最高，时间为22min。     

影响大豆分离蛋白凝胶形成的几种因素的研究

影响大豆分离蛋白凝胶性质的因素有许多,包括离子浓度、pH、热处理强度、凝固剂等.实验通过研究浓度、巯基乙醇、pH、温度四种因素对大豆分离蛋白凝胶形成的影响,确定大豆分离蛋白适宜的凝胶条件.研究结果如下:大豆分离蛋白形成凝胶的适宜浓度为25%,巯基乙醇添加量为0.3%,pH为7.0,温度为90℃;各影响因素的主次关系:大豆分离蛋白浓度为最主要影响因素,其次为巯基乙醇添加量,再次为pH,温度为最次要因素.     

制备条件和测定方法对SPI凝胶特性测定结果的影响

对影响大豆分离蛋白凝胶的形成因素进行了研究。蛋白质浓度、pH、温度和加热时间对所形成凝胶的质构特性都有较大的影响。在形成凝胶的最佳条件下制备凝胶,采用物性仪和一种简易的测定凝胶脆度的方法对几种不同大豆分离蛋白制备的凝胶的脆度进行测定,结果表明,两种方法测定结果无显著性差异,说明这种简易的测定方法可用于评价大豆分离蛋白的凝胶特性。     

大豆分离蛋白的凝胶性及其应用的研究进展

大豆分离蛋白是一种廉价的蛋白质资源,同时还具有多种功能性,凝胶性就是大豆分离蛋白重要的功能性质之一.为表明大豆分离蛋白凝胶性在食品加工中的重要作用,对大豆分离蛋白的凝胶性进行调查研究,概述了大豆分离蛋白凝胶的形成机理,并总结出影响大豆分离蛋白凝胶性能的因素.包括:加热温度、加热时间、离子强度、pH值和酶.此外,还介绍了大豆分离蛋白因其具有良好凝胶性和高蛋白含量的特点,而在食品加工行业中得到的广泛应用.     

不同因素对CaCl2透析诱导大豆分离蛋白冷凝胶特性的影响

以大豆分离蛋白为原料,通过对CaCl2透析诱导形成的冷凝胶的质构特性和持水能力进行测定,考察了温度、蛋白质浓度、加热时间、pH及盐离子浓度对冷凝胶特性的影响。研究结果表明,室温下CaCl2透析诱导形成冷凝胶的方法大大增强了大豆分离蛋白的凝胶性。通过响应面分析分析得出其形成凝胶的最佳条件为:蛋白浓度10%、加热温度85℃、加热时间45 min、CaCl2浓度40 mmol/L、pH8.0左右。     

大豆7S球蛋白凝胶光学性质的研究

本文深入地研究了大豆7S球蛋白凝胶光学和流变学性质与蛋白质浓度、加热温度和加热时间的关系。结果表明在形成蛋白质凝胶(蛋白质浓度≥7.5%)的前提下,低的蛋白质浓度有利于大豆7S球蛋白形成透明性凝胶,但凝胶强度较低;温度＞85℃有利于蛋白凝胶透明性和强度的提高;加热60min.较为适宜。扫描电子显微镜(SEM)观察显示大豆7S球蛋白透明凝胶具有有序微观结构;探讨了大豆7S球蛋白形成透明凝胶机理。可为进一步研究大豆蛋白凝胶的光学性质和研制透明的大豆蛋白产品提供理论依据。     

牛血浆蛋白凝胶特性研究

研究不同加工条件如蛋白浓度、加热温度、离子强度和pH对牛血浆蛋白凝胶特性的影响。结果表明:蛋白浓度的提高有利于凝胶的形成,且形成凝胶的最低血浆蛋白浓度是4.0%;4.8%的血浆蛋白,线性升温到85℃保温20 min,能够很好形成凝胶,呈果冻状,光滑有弹性;NaCl浓度在1.0 mol/L以下时,血浆蛋白凝胶强度随离子强度的变化是先增加后减小,0.3 mol/L时取得最佳效果;在pH6.0~9.0范围内,pH为9.0时牛血浆蛋白凝胶的凝胶强度较好,保水性高,蒸煮损失低。NaCl和pH对于牛血浆蛋白的凝胶特性有极显著的互作效应。     

淀粉、大豆分离蛋白及卡拉胶共混凝胶质构特性的研究

马铃薯淀粉、大豆分离蛋白和卡拉胶为肉制品中常用的三种添加剂.本实验将三者按一定比例混合,研究了浓度和pH,加热温度和时间以及蔗糖和电解质的添加等不同处理条件对混合凝胶质构的影响.结果表明,共混溶液的浓度和pH对共混凝胶的质构特性均有较大的影响;在80℃加热条件下,共混凝胶的主要质构指标均达到峰值;加热时间的增加只对凝胶硬度的增加有一定的作用;蔗糖能提高共混凝胶的弹性;NaCI能提高共混凝胶的硬度和弹性.     

大豆11S球蛋白凝胶形成的影响因素分析

以低温脱脂大豆粕为原料,采用等电点冷沉法浸提11S球蛋白。对11S球蛋白凝胶形成过程中影响凝胶质构的因素进行了分析,研究表明,11S球蛋白凝胶形成时蛋白浓度、加热温度、加热时间、蛋白溶液pH对凝胶质构均有一定的影响。采用正交实验设计,通过质构仪进行物性测定比较其凝胶性,大豆11S球蛋白浓度14%、加热温度90℃、溶液pH为7、加热时间60min条件下形成的凝胶强度最好,其凝胶面积410.30g·s,凝胶力117.9g。     

花生蛋白粉凝胶性改善研究

以花生蛋白粉、卡拉胶、玉米淀粉为原料,考察不同混合比例、混合物浓度、加热温度、加热时间、溶液pH 值对花生蛋白粉凝胶形成的影响,采用物性测试仪对不同条件下所制备凝胶的质构特性--硬度和弹性进行研究。通过正交试验得出改善花生蛋白粉凝胶性最适宜的条件为：花生蛋白粉与卡拉胶和玉米淀粉比例为8.00.0.23:1.77,复配物质量分数为18%,加热温度为90℃、加热时间为30min、pH6.75。测定了产品的耐热性、贮藏性,实验结果表明,花生蛋白粉复配卡拉胶、玉米淀粉所制备的凝胶具有较好的热稳定性和贮藏稳定性。     

Heat-induced gelation of actomyosin

Rheological properties of actomyosin gels were markedly affected by protein concentration, pH and heating temperature. Gel strength increased with increasing protein concentration (30-60 mg ml(-1)) and heating temperature (55-75°C), but decreased with increasing pH (5·5-9·0). Low heating temperatures (50-55°C) favoured the formation of more cohesive actomyosin gels than the higher heating temperatures (60-75°C). Gels formed at low pH (5·5 and 6·0) were less cohesive than those formed at high pH (7·5-9·0). Addition of ATP and pyrophosphate (10 mm) prior to heating decreased gel strength and cohesiveness, whereas EDTA (1-5 mM) reduced gel strength but did not affect gel cohesiveness.     

Gelation of Turkey Breast and Thigh Myofibrils: Effects of pH, Salt and Temperature

Salt concentration >0.1M and pH were important to the development of gel fracture properties. Howcvcr, meat type and salt concentration (0.5–1.0M) did not influence gel shear stress or shear strain. Isothermal heating temperature (55°C or 70°C) affected only gel shear strain. Rheological properties at fracture and nonfracture did not respond alike to changes in gclation conditions. General similarities between breast and thigh myofibril gels implied that protein isoforms were not the main factor influencing gel structure formation.     

Gel Characteristics—Structure as Related to Texture and Waterbinding of Blood Plasma Gels

Heat induced denaturation and aggregation of plasma protein solutions were studied by low shear viscometry and turbidity measurements. The microstructure of blood plasma gels was evaluated by scanning electron microscopy (SEM). Relationships between gel structure, texture, and waterbinding properties of blood plasma gels prepared under various conditions such as different heating temperatures, pH and protein and salt concentrations were investigated. Generally, it was found that the degree of elasticity and waterbinding properties decreased with an increasing degree of random aggregation of the protein gel network. The degree of aggregation increased with increasing protein and salt concentration and decreasing pH from 9 to 6. With increasing heating temperature from 77° C to 92° C, a partial disruption of the gel structure due to local aggregation phenomena was demonstrated by SEM micrographs.     

Effect of gelation factors on the formation and characteristics of protease‐induced whey protein gel

Whey protein gel formed at 10% (w/v) whey protein concentration, 0.5% E/S, pH 7.0, 55°C and 2.5 mM CaCl₂ concentration had an average particle size of 23.46 μm, hardness of 0.46, cohesiveness of 0.13 and adhesiveness of 1.40, and the gel showed semisolid, smooth and creamy texture. There were no distinct changes in gel textural properties after heating at 80 and 90°C for 5 min, respectively, or being kept at 4°C for 1 month. The textural properties of the gel showed no significant difference after its pH was adjusted to 4.5, 5.5 and 7.5 compared with that of pH 6.5 (control gel). However, the average particle size significantly increased after being adjusted to pH 4.5 and pH 5.5. Transmission electron micrographs showed that protease‐induced gel possessed much looser aggregate structure compared with heat‐induced compact gel, which may give support to its potential application in low‐fat foods that no need of extensive heating.     

Gel Characteristics—Waterbinding Properties of Blood Plasma Gels and Methodological Aspects on the Waterbinding of Gel Systems

A methodological study on the waterbinding properties of protein gels was made, where two tests were evaluated. Only one of them, the “net test,” was found useful for work on protein gels. The moisture loss of blood plasma gels was then studied as a function of heating temperature, heating time, pH, protein concentration, and sodium chloride concentration. It was finally demonstrated that a change in the gel structure may affect waterbinding and texture characteristics differently, and these properties should therefore be treated separately when evaluating protein gels. It was, e.g., shown that blood plasma gels became firmer with increasing heating temperature from 72 – 92°C, whereas the waterbinding properties became poorer at temperatures above 77°C and had an optimum at 75 – 77°C.