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大豆7S球蛋白凝胶光学性质的研究 总被引:7,自引:1,他引:6
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。 相似文献
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酪蛋白与乳清蛋白比例对酸奶凝胶性质的影响 总被引:1,自引:0,他引:1
研究了乳中酪蛋白和乳清蛋白比例对凝固型酸奶流变学特性和微观结构的影响,结果表明,固定蛋白质质量分数、降低酪蛋白和乳清蛋白的比例,可以明显提高酸奶凝胶的质量.乳中蛋白质质量分数一致时,酸奶凝胶的硬度、黏度、持水力随着酪蛋白和乳清蛋白比例的减小而增大,凝胶网络结构变得更规则、致密,孔隙更小.在低蛋白质质量分数下,降低乳中酪... 相似文献
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研究了酸法脱酰胺大米蛋白(ADRP)/葡聚糖混合体系的微观结构及流变性质。采用共聚焦激光扫描显微镜观察了ADRP/葡聚糖混合体系的微观结构,结果显示出ADRP之间产生了有效的交联,并且在蛋白质质量分数较高的混合体系中形成了蛋白质网状结构。流变仪观察了混合体系的动力学性质,黏度-剪切速率曲线表明蛋白质交联程度较高的体系黏度增加明显,频率扫描结果进一步证实蛋白质质量分数较高的体系凝胶网络结构的形成;质构仪测试了此凝胶体系的强度,证实混合体系凝胶比单一ADRP的蛋白凝胶具有更高的破裂强度。ADRP和葡聚糖的相分离是混合体系中蛋白质网络结构形成的可能原因。 相似文献
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Koen J.A. Jansens Ine Rombouts Charlotte Grootaert Kristof Brijs John Van Camp Paul Van der Meeren Frederic Rousseau Joost Schymkowitz Jan A. Delcour 《Comprehensive Reviews in Food Science and Food Safety》2019,18(1):84-105
To control and enhance protein functionality is a major challenge for food scientists. In this context, research on food protein fibril formation, especially amyloid fibril formation, holds much promise. We here first provide a concise overview of conditions, which affect amyloid formation in food proteins. Particular attention is directed towards amyloid core regions because these sequences promote ordered aggregation. Better understanding of this process will be key to tailor the fibril formation process. Especially seeding, that is, adding preformed protein fibrils to protein solutions to accelerate fibril formation holds promise to tailor aggregation and fibril techno‐functionality. Some studies have already indicated that food protein fibrillation indeed improves their techno‐functionality. However, much more research is necessary to establish whether protein fibrils are useful in complex food systems and whether and to what extent they resist food processing unit operations. In this review the effect of amyloid formation on gelation, interfacial properties, foaming, and emulsification is discussed. Despite their prevalent role as functional structures, amyloids also receive a lot of attention due to their association with protein deposition diseases, prompting us to thoroughly investigate the potential health impact of amyloid‐like aggregates in food. A literature review on the effect of the different stages of the human digestive process on amyloid toxicity leads us to conclude that food‐derived amyloid fibrils (even those with potential pathogenic properties) very likely have minimal impact on human health. Nevertheless, prior to wide‐spread application of the technology, it is highly advisable to further verify the lack of toxicity of food‐derived amyloid fibrils. 相似文献
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Production of edible nanostructures constitutes a major challenge in food nanotechnology, and has attracted a great deal of interest from several research fields — including (but not limited to) food packaging. Furthermore, whey proteins are increasingly used as nutritional and functional ingredients owing to their important biological, physical and chemical functionalities. Besides their technological and functional characteristics, whey proteins are generally recognized as safe (GRAS). Denaturation and aggregation kinetics behavior of such proteins are of particular relevance toward manufacture of novel nanostructures possessing a number of potential uses. When these processes are properly engineered and controlled, whey proteins may form nanostructures useful as carriers of bioactive compounds (e.g. antimicrobials, antioxidants and nutraceuticals). This review discusses the latest advances in nano-scale phenomena involved in protein thermal aggregation aiming at formation of bio-based nano-coating networks. The extent of aggregation is dependent upon a balance between molecular interactions and environmental factors; therefore, the impact of these conditions is addressed in a critical manner. A particular emphasis is given to the effect of temperature as long as being one of the most critical variables. The application of moderate electric fields (MEF), an emergent approach, as such or combined with conventional heating is considered as it may inhibit/prevent excessive denaturation and aggregation of whey proteins — thus opening new perspectives for development of innovative protein nanostructures (i.e. nano-coatings). A better understanding of the mechanism(s) involved in whey protein denaturation and aggregation is crucial as it conveys information relevant to select methods for manipulating interactions between molecules, and thus control their functional properties in tailor-made applications in the food industry. 相似文献
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对近年来有关植物蛋白的凝胶机理、影响因素进行了综述,在此基础上,阐述了植物蛋白凝胶在食品领域及非食品领域的应用,提出了目前存在的研究空白及问题,为深入研究植物蛋白材料的应用及其降解机制、扩充植物蛋白的应用领域提供一些理论参考。 相似文献
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Hankie Uluko Lu Liu Shu-Wen Zhang 《Critical reviews in food science and nutrition》2016,56(7):1193-1208
A major deterrent to the usage of milk protein concentrate (MPC), a high-protein milk product with increasing demand as a food and sports drink ingredient, has been its poor functional characteristics when compared with other milk protein products such as whey protein concentrate and sodium caseinates. This review discusses the recent research on functional properties of MPC, focusing on factors that may contribute to the poor functional characteristics before, during, and after production. Current research, methods employed, and new understanding on the causes of poor solubility of MPC at mild temperatures (about 20°C) has been presented, including loss of solubility during storage as these areas have received unprecedented attention over the past decade, and also affects other useful functional properties of MPC, such as emulsifying properties, gelation, and foaming. Processing methods, which include heat treatment, high-pressure application, microwave heating, ultrasound application, and enzyme and salts modification, have been used or have potential to modify or improve the functional properties of MPCs. Future research on the effects of these processing methods on the functional properties, including effects of enzyme hydrolysis on bitterness and bioactivity, has also been discussed. 相似文献
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Nature of Stem Bromelain Treatments on the Aggregation and Gelation of Soybean Proteins 总被引:10,自引:0,他引:10
Aggregation and gelation of heated soybean proteins treated with stem bromelain were investigated by determination of sulfhydryl and hydrophobicity, by polyacrylamide gel electrophoresis and by scanning electron microscopy. The heat-induced, water-soluble soybean protein aggregates were initially unfolded by treatment with stem bromelain and released 7S and 4S proteins. The 2S protein was completely decomposed. The enzyme attacked the basic subunits of 11S globulin and converted them to low molecular weight fragments. Aggregation and gelation developed with icnrease of fragments. Noncovalent forces, possibly through hydrophobic interaction, played an important role in the aggregation process. Scanning electron microscopy revealed a fine network structure which suggested the combination of low molecular weight fragments. 相似文献
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Stefan K. Baier D. Julian McClements 《Comprehensive Reviews in Food Science and Food Safety》2005,4(3):43-54
How thermostability and gelation of globular protein are affected by cosolvent systems present in food systems is critical to understanding their functionality. The expression of these functional attributes depends on the molecular structure and thermal‐mechanical history of the protein, as well as its chemical environment. To improve the design of processing protein‐containing food systems, one must fully understand the thermodynamic, kinetic, and structural impact of cosolvent on globular protein gelation. This review focuses on the impact of weakly interacting neutral cosolvent systems (for example, sugars and polyols) on the gelation of globular proteins. The physicochemical mechanisms by which these cosolvent systems can modulate protein gelation are highlighted from a thermodynamic, kinetic, and structural point of view. 相似文献
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We investigated the properties of gels that were formed by adding emulsifying salts, such as tetrasodium pyrophosphate (TSPP), to reconstituted milk protein concentrate solution. The pH of a 51 g/L milk protein concentrate solution was adjusted to 5.8 after adding TSPP. Milk protein concentrate solutions were placed in glass jars and allowed to stand at 25°C for 24 h. Gels with the highest breaking force were formed when TSPP was added at a concentration of 6.7 mM, whereas no gel was formed when TSPP was added at concentrations of ≤2.9 or ≥10.5 mM. Several other phosphate-based emulsifying salts were tested but for these emulsifying salts, gelation only occurred after several days or at greater gelation temperatures. No gelation was observed for trisodium citrate. Gelation induced by TSPP was dependent on pH, and the breaking force of gel was greatest at pH 6.0. Furthermore, when the concentration of milk protein concentrate in solution was increased to 103 g/L, the breaking force of the gel increased, and a clearly defined network between caseins could be observed by using confocal scanning laser microscopy. These results suggest that TSPP-induced gelation occurs when the added TSPP acts with calcium as a cross-linking agent between dispersed caseins and when the balance between (a reduced) electrostatic repulsion and (enhanced) attractive (hydrophobic) interactions becomes suitable for aggregation and eventual gelation of casein molecules. 相似文献
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《International Dairy Journal》2000,10(8):529-539
Mechanical and structural properties of transglutaminase-induced casein gels are described here and compared with those of traditional acid casein gels. These gels were characterised by rheology and microscopy (confocal laser scanning microscopy and transmission electron microscopy). Unlike traditional casein gels produced by acidification and/or renneting which lead to gels cross-linked by weak physical interactions, gels formed using transglutaminase are covalently cross-linked. Gels with different characteristics can therefore be formed in this way and have some unusual and interesting features in terms of strength, kinetics of gelation, sensitivity to heat treatment and syneresis behaviour. The first steps of the transglutaminase-induced micellar aggregation were followed by turbidimetry and a mechanism for the aggregation process proposed. 相似文献
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Improvement of canola protein gelation properties through enzymatic modification with transglutaminase 总被引:2,自引:0,他引:2
Alexandra Pinterits 《LWT》2008,41(1):128-138
Enzymatic modification with transglutaminase (TG) was used to enhance the gelation of canola protein isolate (CPI) and thus improve its potential as a food ingredient. The effects of CPI concentration, TG concentration, treatment temperature and treatment time on CPI gelation properties were evaluated. A texture analyzer, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscopy were used to characterize the resulting networks. The protein concentration, amount of TG, and treatment temperature were found to significantly impact gel strength. It was found that gelation can be improved by increasing the amounts of protein and TG and by keeping the treatment temperature close to 40 °C. SDS-PAGE showed that cross-linking of subunits occurred through TG treatment thus helping to explain the increase in gel strength observed during texture analysis. Micrographs further corroborated the trends noted during rheological studies. 相似文献