共查询到19条相似文献,搜索用时 140 毫秒
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通过不同截留分子质量的再生纤维素膜过滤纯化牦牛原乳清液和牦牛甜乳清液,分别制取牦牛原乳清蛋白浓缩物(native whey protein concentrate,NWPC)和牦牛甜乳清蛋白浓缩物(sweet whey protein concentrate,SWPC),研究蛋白含量不同的乳清蛋白浓缩物(whey protein concentrate,WPC)主要成分(乳糖含量、pH值和总蛋白质含量)和功能特性(溶解性、持水性、持油性、起泡性、乳化性及热稳定性)的特征。结果表明:10 000 Da再生纤维素膜透析得到的牦牛WPC中总蛋白含量达到80%以上,不含乳糖,功能特性(溶解性、持水性、持油性、起泡性、乳化性及热稳定性)均显著高于经3 500 Da卷式膜、5 000 Da再生纤维素膜透析得牦牛WPC,WPC蛋白含量越高,其功能特性越好;不同蛋白含量的牦牛SWPC起泡能力、泡沫稳定性、乳化活性和乳化稳定性均显著(P<0.05)高于牦牛NWPC。牦牛乳WPC最不稳定温度为85 ℃,高于荷斯坦牛乳WPC的80 ℃,热处理会适当改善牦牛WPC的起泡性能、乳化性能和热稳定性。通过膜牦牛处理获取的高蛋白含量的WPC,功能特性较好,应用广泛,对解决牦牛乳清资源的利用问题、保护环境、提高企业的经济效益起到关键性作用。 相似文献
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以钓带鱼、外洋带鱼和雷达网带鱼为研究对象,探讨其在不同加热温度下肌球蛋白功能特性及组织微观结构的变化。将3种带鱼分别于30、50、70、90℃下水浴处理10 min,测定其肌肉蒸煮损失率、持水力以及肌球蛋白浊度、溶解度、乳化能力、起泡性(foaming capacity,FC)、泡沫稳定性(foaming stability,FS)和羰基含量。同时,利用苏木精-伊红(hematoxylin-eosin,HE)染色分析不同加热温度对3种带鱼组织微观结构的影响。结果表明:随着加热温度升高,3种带鱼的肌肉蒸煮损失率、持水力逐渐降低,肌球蛋白浊度和羰基含量增加,溶解度、乳化性及乳化稳定性、FC及FS均不断降低;其中雷达网带鱼肌肉持水力、肌球蛋白溶解度的下降幅度和肌球蛋白浊度的上升幅度均小于其他2种带鱼;此外,HE染色结果显示,随着加热温度升高,3种带鱼的肌肉组织中肌纤维束间隙加大,并出现不同程度的断裂,当加热温度为50℃时,雷达网带鱼肌肉组织中胶原纤维和肌纤维完整性最好。由此可知,加热温度提高的同时,3种带鱼的肌肉蛋白质品质均呈下降趋势,其中雷达网带鱼肌肉蛋白质的品质稳定性最佳。 相似文献
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本研究以新鲜牦牛乳为原料,添加钙盐后利用其等电点分离提取牦牛奶中的不同酪蛋白,利用单因素实验筛选牦牛奶中α-、β-、κ-酪蛋白的提取分离参数;并利用电泳(SDS-PAGE)分析牦牛乳不同酪蛋白纯度。同时对牦牛乳中α-、β-、κ-酪蛋白的溶解性、乳化性、发泡性进行分析比较。结果表明:牦牛奶不同酪蛋白分离的最佳Ca~(2+)浓度为0.08 mol/L,最佳温度2℃,此时牦牛乳中α-、β-酪蛋白分离效果较好。牦牛乳不同酪蛋白在等电点(p I)附近时,α-、β-、κ-酪蛋白溶解性、乳化性、发泡能力最低,泡沫稳定性最好。等电点附近酪蛋白的溶解度最低,α-、β-酪蛋白pH值在2.1时溶解度最高(分别为60%、80%),而k-酪蛋白在pH值6.22时最高(43%);在40~80℃范围内,κ-酪蛋白溶解度受温度影响显著;当pH值为2.1时,α-、β-、κ-酪蛋白的乳化能力和发泡能力都最大,其乳化稳定性则是远离等电点后逐渐上升;本研究旨在为牦牛乳酪蛋白的利用和深加工提供思路,为云南特色乳制品的开发利用提供科学依据。 相似文献
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采用藏北地区牦牛肉为原料,制备一种牦牛肉蛋白质粉。经过调制,开发出一种以牦牛肉蛋白质粉为主要原料的固体饮品型运动补剂。经过100 d的长跑运动员实验,证实这种运动补剂具有显著提高运动员腿部肌肉力量和长跑运动成绩的作用(P0.05),并对运动员的免疫功能有显著的调节作用(P0.05)。 相似文献
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为了探究储藏温度对不同大米蛋白功能特性的影响,本实验以中国东北地区‘稻花香二号’‘辽星’和‘盐丰’大米为对象,以大米蛋白的溶解性、持水性、持油性、起泡性质和乳化性质为指标,分析其在4、30 ℃和70 ℃储藏期间的变化情况,以期为优质大米储藏过程中蛋白品质控制提供参考。结果表明,蛋白持水性和起泡性在不同储藏温度下随时间延长总体呈下降趋势,而持油性总体呈上升趋势。‘稻花香二号’和‘辽星’蛋白的泡沫稳定性在不同储藏温度下随时间延长总体呈上升趋势,而‘盐丰’蛋白总体呈下降趋势。在4 ℃储藏期间,3 种大米蛋白的乳化稳定性总体呈下降趋势,‘稻花香二号’和‘辽星’的蛋白溶解度和乳化性总体呈下降趋势,而‘盐丰’的蛋白溶解度和乳化性呈显著上升趋势(P<0.05)。在30 ℃储藏期间,3 种大米蛋白溶解度总体呈下降趋势,而乳化性和乳化稳定性总体显著上升(P<0.05)。在70 ℃储藏期间,3 种大米蛋白的溶解度和‘辽星’蛋白的乳化稳定性总体显著下降(P<0.05),而‘稻花香二号’蛋白乳化性总体呈上升趋势。综上,在不同温度储藏期间,3 种大米蛋白的功能特性均发生显著变化。 相似文献
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绿豆分离蛋白功能特性研究 总被引:16,自引:5,他引:16
本文研究了绿豆分离蛋白的功能特性,同时研究了pH值,温度诸因素对绿豆分离蛋白功能特性的影响。结果表明,绿豆分离蛋白具有较好的溶解性和起泡性,一定的保水性和乳化性,但是绿豆分离蛋白的吸油性较差。绿豆分离蛋白形成稳定凝胶的条件是其溶液浓度≥10%。 相似文献
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为探究喷雾干燥对籽瓜种子蛋白质理化结构及功能特性的影响。以冷冻干燥的籽瓜种子蛋白质作对比,探究喷雾干燥对蛋白质体积密度、色泽、体外消化率、氨基酸组成、热变性温度、表面疏水性、内源荧光、二级结构、超微结构及功能特性的影响。研究表明:与冷冻干燥相比,喷雾干燥后的籽瓜种子蛋白质体积密度较大为0.34 g/m L,白度较大,色泽较好,体外消化率较高为96.0%,赖氨酸与精氨酸比值较低为0.20,必需氨基酸组成基本没有变化,热稳定性较好,变性峰值温度、热变性焓值较大分别为89.06℃、1.751 J/g,内源荧光最大发射波长由352 nm向354 nm发生红移,表面疏水性增加为4097.5,β-转角含量增加为29.62%,α-螺旋、β-折叠和无规则卷曲均向β-转角转变,溶解性、持水持油性、乳化特性、起泡特性等功能特性均变差。 相似文献
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热加工对小麦蛋白结构和消化特性的影响 总被引:1,自引:0,他引:1
研究100℃热处理不同时间(5min、15min、30min)对小麦蛋白分子结构及其体外消化的影响。结果表明,随着热处理时间的增加,麦谷蛋白和麦醇溶蛋白的α-螺旋结构逐渐减少,无规则卷曲结构的相对含量分别增加了8.2%、7.98%,这与小麦蛋白的电镜微观结果一致;麦谷蛋白与麦醇溶蛋白的平均粒径在热处理30min时分别达到了237.4μm、254.3μm;根据凝胶电泳结果显示,热处理对麦醇溶蛋白和麦谷蛋白的亚基分子量没有显著影响;在特定的热处理时间内,小麦蛋白的消化程度与加热时间呈正比关系。综上,麦醇溶蛋白与麦谷蛋白在热处理下发生的结构变化具有一致性,且在100℃ 30min处理下的小麦蛋白具有最高的消化率。 相似文献
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Canola meal protein isolates were prepared from defatted canola meal flour using alkaline solubilization and acid precipitation. A central composite design was used to model 2nd-order response surfaces for the protein yield and the functional properties of protein isolates. The solubilization pH and precipitation pH were used as design factors. The models showed that the protein yield and functional properties of isolates, such as water absorption and fat absorption, were sensitive to both solubilization pH and precipitation pH, whereas the emulsification was sensitive to only solubilization pH. Gel electrophoresis analysis of protein fractions gave evidence to the compositional changes between proteins isolated under different conditions. Differences in glass transition temperatures suggest that proteins tend to be more denatured when solubilized at highly alkaline conditions. These conformational and compositional changes due to different protein separation conditions have contributed to the changes in functional properties of protein isolates. PRACTICAL APPLICATION: Protein isolation conditions may be determined primarily through optimization of total protein yield. Improvements in protein functional properties may be achieved with a relatively small sacrifice in yield by altering isolation conditions. 相似文献
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Linlin Wang Cunfang Wang Xiaoning Zhang Xiaoxue Fan Xiaoqing Shao 《International Journal of Food Science & Technology》2021,56(12):6580-6590
This study investigated the changes in the characteristics of goat milk protein in the presence of trehalose, chitooligosaccharide and pectin during two practical dairy processing operations of pasteurisation and spray drying. The highest denaturation temperature and the largest particle size of milk protein were found in goat milk added with pectin after pasteurisation. And particles with more uniform and compact morphology were observed in goat milk protein with these three saccharides. An elevated emulsifying activity index of 24.37 m/g−2 was observed in protein after spray drying due to chitooligosaccharide. And the foam stability was also improved significantly in the presence of trehalose and pectin during pasteurisation. During spray drying, saccharides showed the stabilizing effect on goat milk protein. This study revealed a complex interplay between the type of saccharides and the processing operation applied to goat milk, which might be of great significance for the production and processing of goat milk. 相似文献
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目的 探究不同挤压温度(60、80、100、120、140℃)对火麻蛋白的理化、加工功能特性的影响。方法 以火麻蛋白饼粕为原料,经过挤压前处理后,使用碱溶酸沉法从火麻蛋白饼粕中提取火麻蛋白,测定其提取率、等电点、氮溶解指数、体外消化率、巯基和二硫键含量、持水性和持油性,并利用傅里叶红外光谱、内源性荧光光谱、差式扫描量热仪、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、扫描电镜对火麻蛋白进行表征。结果 挤压处理会导致火麻蛋白的提取率、体外消化率和游离巯基含量提高,但在140℃时游离巯基含量降低,等电点、持水性、总巯基和二硫键含量均有所下降,随着挤压温度的升高,火麻蛋白的氮溶解指数先下降再升高后下降,持油性先降低后升高;傅立叶红外光谱和内源性荧光光谱结果表明挤压不会引起火麻蛋白生成新的吸收峰,挤压温度的升高会使其荧光强度先增加后减少;差式扫描量热仪结果表明在挤压温度为120℃时,火麻蛋白氢键断裂,热焓值升高;十二烷基硫酸钠-聚丙烯酰胺凝胶电泳结果显示挤压处理使火麻蛋白形成了大的聚集体,条带较未挤压的火麻蛋白颜色变浅;观察扫描电镜发现挤压处理导致火麻蛋白表面孔隙减小,并且随着挤压温度的升高逐渐形成了致... 相似文献
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B O Juliano A A Antonio B V Esmama 《Journal of the science of food and agriculture》1973,24(3):295-306
The protein of brown rice became more evenly distributed as protein content increased. Kjeldahl protein content of brown rice provided a better indication of milled rice protein content than histological examination of individual grains because protein content varied among grains. The increase in protein content was mainly due to an increase in the number of protein bodies. Screening 10 493 varieties from the world rice collection for lysine content by dye-binding capacity showed that lysine content of rice protein varied only by at most 0.5 % point at any protein level. A negative correlation between the lysine content of protein and protein content of brown and milled rice was observed only in samples with protein below 10%. As protein content increased water-soluble nitrogen also increased as a percentage of brown rice. 相似文献
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《食品与发酵工业》2019,(22)
以甘肃省甘南州公牦牛半膜肌为研究对象,通过对自然风干40 d过程中肌原纤维蛋白中羰基、巯基、二酪氨酸含量,以及过氧化值(peroxide ralue,POV)和硫代巴比妥酸值(thiobarbituric acid value,TBA)的测定来评价蛋白氧化和脂肪氧化程度,并且通过分析氨基酸的变化规律探讨传统风干牦牛肉在加工过程中肌原纤维蛋白氧化对氨基酸的影响。结果表明,随着风干时间的延长,风干肉羰基含量显著增加,巯基含量显著降低,二酪氨酸含量逐渐升高; POV值和TBA值均呈逐渐升高的趋势;同时酪氨酸、亮氨酸及苯丙氨酸对氧化作用非常敏感,氧化前后其含量变化显著(P<0. 05)。综合分析,由相关性分析看出蛋白氧化是由脂肪氧化引起,氧化会在一定程度上破坏肉制品的营养特性和风味,该文结果明确了风干时间对牦牛肉品质的影响,为牧区牦牛肉制品的加工及加工方式提供了理论依据。 相似文献
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A growing demand for functional plant proteins could be identified, which properties are customized for specific applications and formulations as food ingredients. Native lupin proteins (α, β, γ) conglutin have a good solubility at appropriately chosen conditions. A novel procedure has been proposed to maintain the native protein properties. Lupin proteins are extracted from hexane deoiled lupin. The protein product type E comprises high molecular weight proteins (α, β‐conglutin( which are separated using alkaline extraction and acid precipitation procedures. The protein product type F is enriched in the γ‐conglutin fraction and is separated from the acid pre‐extract applying cross flow filtration at pH 7–8. For the zirconium oxide membrane the filtration rate can be increased by appropriately chosen pH conditions up to 70 l/m2h. Lupin protein fraction (type E and F) are highly soluble protein isolates with outstanding emulsification, salt tolerance and foaming properties. These new lupin proteins (type E and F) offer extremely interesting properties for application in food systems and are available from pilot plant fractionation. 相似文献