食用胶对猪肉肌原纤维蛋白功能特性的影响

将不同添加量的卡拉胶、亚麻籽胶、黄原胶和魔芋胶添加到猪肉肌原纤维蛋白溶液中,通过测定肌原纤维蛋白的乳化能力、凝胶质构特性、保水性和凝胶白度,研究食用胶对肌原纤维蛋白功能特性的影响。结果表明:与未添加食用胶的对照组相比,四种食用胶均可显著提高肌原纤维蛋白的乳化能力、凝胶硬度和弹性以及保水性(p<0.05),且添加量越高,增加的幅度越大;但添加食用胶后,肌原纤维蛋白的凝胶白度略有下降。因此,卡拉胶、亚麻籽胶、黄原胶和魔芋胶对肌原纤维蛋白的功能特性具有显著的影响。      

马铃薯淀粉对鲤鱼肌原纤维蛋白功能特性的影响

将马铃薯淀粉（不同添加量0%、1%、2%、3%和4%）添加到鲤鱼肌原纤维蛋白中,通过测定肌原纤维蛋白的浊度、乳化性、凝胶的硬度、弹性、保水性、白度值等指标,较为系统地研究了马铃薯淀粉对鲤鱼肌原纤维蛋白功能特性的影响。结果表明:在温度一定时,淀粉-蛋白复合物的浊度随着马铃薯淀粉添加量的增大而升高;在马铃薯淀粉添加量一定时,淀粉-蛋白复合物的浊度随着温度的升高而升高。随着马铃薯淀粉添加量的增加,乳化活力和乳化稳定性呈先上升后下降后又有所增加的趋势,在马铃薯淀粉添加量为2%和1%时乳化活性和乳化稳定性分别达到最大值25.66m2/g,90.67%。当温度相同时,淀粉-蛋白复合凝胶的硬度和弹性值随着马铃薯淀粉添加量的增大而升高,在80℃条件下,添加了4%淀粉的样品与对照组相比硬度和弹性分别提高了65.85%,20.85%,且效果显著（p<0.05）,而随着马铃薯淀粉添加量的增加,凝胶持水性增大（p<0.05）,最大增加了18.75%,但凝胶的白度值呈现下降趋势。因此添加马铃薯淀粉可以有效改善肌原纤维蛋白的功能特性。      

白酒对秋刀鱼肌原纤维蛋白结构和功能性质的影响

以秋刀鱼为原料,研究白酒添加量对秋刀鱼肌原纤维蛋白(Myofibrillar protein,MP)溶解度、乳化性、浊度、表面疏水性、凝胶特性和巯基含量的影响。结果表明:随着白酒添加量的增加,MP溶解度、乳化性、凝胶硬度、弹性、咀嚼性、内聚性及保水性呈先上升后下降的趋势,凝胶白度值无明显变化;浊度、表面疏水性、巯基含量呈先下降后上升的趋势。整体来看,白酒处理对秋刀鱼肌原纤维蛋白的功能特性影响较大,且在白酒添加量为5%~7%时对凝胶特性的改善效果较好。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳研究发现,白酒能够促进蛋白质的溶解,并使溶出的蛋白质通过聚合作用形成大分子物质。     

Covalent chemical modification of myofibrillar proteins to improve their gelation properties: A systematic review

To improve the quality of meat products is a constant focus for both the meat industry and scientists. As major components in meat protein, the gelation properties of myofibrillar proteins (MPs) predominantly determine the sensory quality and product yield of the final product. Naturally or artificially occurring covalent modifications are known to largely affect MP functionality by changing the protein structure and forming aggregates, leading to both favorable and unfavorable outcomes. The review aims to summarize the mechanisms associated with several covalent modifications and the recent developments in enhancing MP gelation properties. Various extrinsic and intrinsic parameters controlling oxidation, phenolic–protein interactions, enzyme catalysis, glycation, and isoelectric solubilization/precipitation, and their effects on the characteristics of heat-induced MP gels are discussed. This article provides an improved understanding of the covalent modifications that occur mainly in the MP system and how they can be utilized to promote its gelation properties. Covalent modifications exhibited dose-dependent and dual-role manners for MP gelation properties. Mild oxidation, enzyme catalysis, and isoelectric solubilization/precipitation treatment would be beneficial to form more aligned and cross-linked three-dimensional networks for MP gels because of moderate protein aggregation. However, an excessive aggregate impedes the MP gelation behavior, leading to reduced gelation quality. Glycation effectively increased hydrophilicity of MPs and phenolic conjugation provides MPs with novel bioactivity. A proper utilization of such a process or even a rational combination of them allowed us to enhance the gelation properties of MP with assorted appreciated functionalities and further improve the quality of meat products.     

红曲红添加量对猪肉肌原纤维蛋白功能性质和结构的影响

探究红曲红添加量对猪肉肌原纤维蛋白(myofibrillar protein,MP)功能特性的影响,为低硝肉制品的开发提供理论依据。以红曲红添加量(质量分数)0、0. 1%、0. 15%、0. 2%、0. 25%处理猪背最长肌,考察猪肉MP功能指标和分子结构的变化。结果表明,随着红曲红添加量增加,MP的溶解性、乳化性、巯基含量、储能模量均先升高后降低,羰基含量和表面疏水性则先下降后上升,红外光谱分析表明,α-螺旋含量随着红曲红添加量的增加先增大后减小,β-折叠、β-转角以及无规则卷曲含量则呈先减小后增大。因此,降低亚硝酸钠使用量会严重影响MP的功能性质,红曲红添加量过低或过高MP的功能特性均不佳,红曲红添加量为0. 15%时,能显著改善低硝条件下MP的功能性质(P<0. 05)。     

不同盐浓度下黄原胶对大豆分离蛋白—肌原纤维蛋白复合凝胶性质的影响

研究不同盐浓度下黄原胶对大豆分离蛋白(SPI)—肌原纤维蛋白(MP)复合体系凝胶特性和结构的影响。结果表明:在0.1,0.3 mol/L NaCl条件下,低含量SPI有利于MP—SPI复合体系的凝胶及提高凝胶持水性;黄原胶也可提高MP—SPI复合凝胶的持水性。环境扫描电镜显示:黄原胶的强持水能力及大豆蛋白的填充起到了凝胶促进作用。在高盐浓度下,SPI的加入,对于MP—SPI复合凝胶强度和持水性均有破坏效应;对于纯MP凝胶,黄原胶的加入会弱化凝胶强度,但可提升凝胶持水性;对于MP—SPI复合凝胶样品,随着黄原胶用量的增加,肌纤维蛋白—大豆蛋白复合凝胶的凝胶强度和持水性均呈现增加趋势。说明多糖—MP—SPI复合体系中,三者相互作用受盐浓度影响显著,在低盐条件下,低浓度大豆蛋白和高浓度黄原胶的加入可较好地改善复合蛋白凝胶性质。     

Changes in functional properties of common carp (Cyprinus carpio) myofibrillar protein as affected by ultrasound-assisted freezing

Ultrasound-assisted freezing (UF) has proven to be a method that can effectively increase the freezing rate of frozen food and improve its quality. The functional properties of myofibrillar proteins (MP) are important factors that affect the further processing quality of meat products. At present, the effect of UF on the functional properties of frozen MP is not yet clear. Therefore, in the present study, changes in the functional properties (emulsifying and gel properties) of MP in common carps (Cyprinus carpio) frozen with UF at different power levels were investigated. The results revealed that, compared with immersion freezing (IF), UF at 175 W (UF-175) effectively inhibited the decrease in protein solubility, absolute Zeta potential, emulsion activity index, storage modulus (G'), and loss modulus (G'') caused by freezing. UF-175 sample had lower protein turbidity, and smaller protein particle size than any other frozen samples (P < 0.05), which suggested that UF-175 inhibited protein aggregation induced by freezing. In addition, shorter T₂₁ and T₂₂ relaxation times were obtained in UF-175 sample than other frozen samples, indicating that UF-175 reduced the mobility of immobilized and free water. Accordingly, UF-175 sample had higher gel strength and water holding capacity than other frozen samples (P < 0.05). A denser and more uniform gel network structure was also found in UF-175 sample than other frozen samples. In general, improved functional properties of common carp MP can be achieved by optimal UF.     

Effect of cold atmospheric plasma on the physicochemical and functional properties of myofibrillar protein from Alaska pollock (Theragra chalcogramma)

This study aimed to investigate the effect of cold atmospheric plasma (CAP) on the physicochemical and functional properties of myofibrillar protein isolated from Alaska pollock (Theragra chalcogramma) muscle. Free sulfhydryl content, surface hydrophobicity, turbidity, differential scanning calorimetry, SDS-PAGE, heat-induced myofibrillar protein gel properties and water holding capacity were determined to evaluate the effect of CAP treatment on protein properties. CAP treatment from 10 to 60 kV for 10 min significantly (P < 0.05) increased the water holding capacity, textural properties and colour properties of heat-induced myofibrillar protein gel. As treatment voltage increased, free sulfhydryl content decreased significantly, while the turbidity and surface hydrophobicity of myofibrillar protein were increased. DSC data showed enhancement of thermal stability of the treated samples; however, the electrophoretic profile displayed a significant reduction in the band's intensity of protein at a higher voltage. These results suggest that cold atmospheric plasma (CAP) treatment could be used as an alternative approach to enhance the gelling properties of myofibrillar protein from Alaska pollock.     

Modification methods and applications of egg protein gel properties: A review

Egg protein (EP) has a variety of functional properties, such as gelling, foaming, and emulsifying. The gel characteristics provide a foundation for applications in the food industry and research on EP. The proteins denature and aggregate to form a dense three-dimensional gel network structure, with a process influenced by protein concentration, pH, ion type, and strength. In addition, the gelation properties of EP can be altered to varying degrees by applying different treatment conditions to EP. Currently, modification methods for proteins include physical modification (heat-induced denaturation, freeze–thaw modification, high-pressure modification, and ultrasonic modification), chemical modification (glycosylation modification, phosphorylation modification, acylation modification, ethanol modification, polyphenol modification), and biological modification (enzyme modification). Pidan, salted eggs, egg tofu, and other egg products have unique sensory properties, due to the gel properties of EP. In accessions, EP has also been used as a new ingredient in food packaging and biopharmaceuticals due to its gel properties. This review will further promote EP gel research and provide guidance for its full application in many fields.     

Changes in physicochemical properties and myofibrillar protein properties in grass carp salted by brining and injection

The aim of this study was to investigate the changes in physicochemical properties and myofibrillar protein properties of grass carp meat during brining and brine injection at 4 °C. The time reached equilibrium was 7 h in brining group and 5 h by injection, where the salt content was about 1.76%. The water content, water holding capacity and yield in injection group (86.59%, 9.18% and 110%, respectively) were higher than brining group (84.76%, 11.47%, and 108%, respectively) at equilibrium point significantly (P < 0.05). This was attributed to the more swollen filament lattices and disordered protein structure in injection group (P < 0.05). The myofibrillar protein structure was compared, including sulphydryl content, surface hydrophobicity, solubility, sodium dodecyl sulphate polyacrylamide gel electrophoresis pattern and secondary structure. The injection group presented the better quality of salted fish meat in shorter time.     

琼胶寡糖对冻藏南美白对虾蛋白质功能特性的影响

目的 探究琼胶寡糖对冻藏南美白对虾蛋白质功能特性的影响。方法 采用蒸馏水、1.5%和3.0%三聚磷酸钠、1.5%和3.0%琼胶寡糖浸泡南美白对虾,分别在冻藏第0、20、40、60、80和100 d时进行取样,测定其肌原纤维蛋白溶解性、浊度、乳化性(emulsifying activity index, EAI)、起泡性(foaming capacity, FC)和热稳定性。同时,利用苏木精-伊红(hematoxylin and eosin, HE)染色观察肌肉组织微观结构。结果 在冻藏过程中,琼胶寡糖与三聚磷酸钠的作用效果相当,且1.5%、3.0%琼胶寡糖显著改善了虾仁肌原纤维蛋白溶解性、EAI和FC的降低以及浊度的增加情况,增加了其热稳定性。HE染色结果显示,新鲜虾仁内部肌肉组织排列紧密有序,而冻藏100 d后,各处理组虾仁肌肉纤维均有不同程度的扭曲断裂,其中3.0%琼胶寡糖组虾仁肌纤维间的连接仍十分紧密,组织结构最为完整。结论 琼胶寡糖能有效保持冻藏南美白对虾蛋白质功能特性,维持肌肉组织结构,提高虾类品质。本研究为水产品抗冻剂的开发提供了借鉴和参考。     

Effects of Agaricus bisporus on gel properties of chicken myofibrillar protein

The gel-forming ability of myofibrillar protein (MP) is highly correlated with the characteristics of emulsified meat products. Incorporation of Agaricus bisporus (Ab) powder into MP gels may enhance its gel properties to facilitate the development of a novel and safe meat product. Therefore, this study investigated the effects of Ab powder on gel strength, water holding capacity (WHC), texture, rheological behaviour, LF-NMR spin–spin relaxation (T₂), microstructure and protein secondary structure of the MP gel system. The results indicated that the gel strength, WHC, G' value and G" value were significantly improved when the addition of Ab powder increased from 0% to 6% (P < 0.05). Meanwhile, the T₂ relaxation time was shortened, and free water was transformed into immobilised water. The texture of the gel was improved when 1%–4% Ab powder was added compared to the control. Furthermore, Ab filled in the gel network and promoted the unfolding of MP α-helix and the formation of MP β-sheet during the thermal denaturation of MP, leading to a dense aggregated network structure. The study suggested that Ab could be a promising ingredient in improving chicken MP's gel properties and developing fat-reduced meat products.     

热烘改性对大豆分离蛋白功能性的影响

研究了利用热处理对大豆分离蛋白(SPI)进行改性。热烘改性对SPI的吸水性、吸油性、发泡性和泡沫稳定性无显著性影响,常温粘度、高温粘度、耐热性、凝胶性和保水性分别比对照提高了118%、135%、108%、81%和83%。比较适宜的热烘改性条件为10min/85℃。     

鸡肉肌原纤维蛋白静态流变特性的研究

利用流变仪研究了肌原纤维蛋白(MP)浓度、温度、pH和离子强度四个因素对肌原纤维蛋白静态流变特性的影响。运用幂率定律计算出K(粘度系数)和n(流变指数)。结果表明:MP样品的剪切应力均随着MP浓度和离子强度的增大而上升,而随着温度和pH的上升先增大后减小;K和n与肌原纤维蛋白浓度,温度,pH和离子强度有关;肌原纤维蛋白溶液的n值最大为0.463,当MP溶液浓度为30mg/mL,pH6.0,离子强度0.6时,n值最小为0.162,且n值随MP浓度和离子强度的增加而降低,说明流体假塑性随MP浓度和离子强度的增加而增加。      

超声波处理对猪肉肌原纤维蛋白理化及乳化特性的影响

采用超声波技术对猪肉肌原纤维蛋白(myofibrillar proteins,MP)进行改性处理,研究超声功率(0,80,140,180,200W)对肌原纤维蛋白理化与乳化特性的影响。结果表明,与未经超声处理的肌原纤维蛋白比较,随着超声功率的增加,MP体积等效平均粒径(d4,3)降低,而溶解度、电位绝对值、乳化活性及乳化稳定性均显著升高。超声功率达到180W时,该处理的肌原纤维蛋白制备的乳化液表现出较高的乳化活性和乳化稳定性,乳化稳定性的提高与增加的电位和降低的平均粒径有关,光学显微镜观察发现该乳化液表现出相对较低的油滴大小。相关性分析结果表明,超声功率与d4,3极显著负相关(P≤0.01),与溶解度、电位、乳化活性及乳化稳定性显著正相关(P≤0.05)。     

Emulsion-forming properties of heat-induced pork myofibrillar protein affected by NaCl

The emulsification characteristics of myofibrillar proteins (MPs) with different NaCl concentrations also affect the quality of meat products after cooking. We investigated the effects of heating (100 °C) on the solubility, emulsifying activity, and conformational and environmental changes of MPs prepared with different NaCl concentrations. Emulsifying activity increased with increasing NaCl prior to heating, but there was no significant effect after heating. The viscosity increased and particle size decreased with increasing NaCl before heating, but these properties did not change after heating. NaCl did not affect the amount of α-helix and β-sheet. We deduced that the different emulsifying activity of myofibrillar proteins with different NaCl concentrations after heating may have been due to changes in the local environment of MPs. An understanding of the physicochemical and functional properties of MPs would unlock an area for development of meat products at different NaCl and temperature in the food industry.     

Modification of plant proteins for improved functionality: A review

The market trend towards plant-based protein has seen a significant increase in the last decade. This trend has been projected to continue in the coming years because of the strong factors of sustainability and less environmental impact associated with the production of plant-based protein compared to animal, aside from other beneficial health claims and changes in consumers' dietary lifestyles. In order to meet market demand, there is a need to have plant-based protein ingredients that rival or have improved quality and functionality compared to the traditional animal protein ingredients they may replace. In this review article, we present a detailed and concise summary of the functionality challenges of some plant protein ingredients with associated physical, chemical, and biological processing techniques (traditional and emerging technologies) that have been attempted to enhance them. We cataloged the differences between several studies that seek to address the functionality challenges of selected plant-based protein ingredients without overtly commenting on a general technique that addresses the functionality of all plant-based protein ingredients. Additionally, we elucidated the chemistry behind some of these processing techniques and how they modify the protein structure for improved functionality. Although, many food industries are shifting away from chemical modification of proteins because of the demand for clean label product and the challenge of toxicity associated with scale-up of this technique, so physical and biological techniques are widely being adopted to produce a functional ingredient such as texturized vegetable proteins, hydrolyzed vegetable protein, clean label protein concentrates, de-flavored protein isolates, protein flour, and grits.     

酶改性大豆分离蛋白的制备及产品功能性的研究

为了改善碱溶酸沉法大豆分离蛋白产品(简称SPI)的功能性,采用有限酶解的方法,从6种蛋白酶中选出中性蛋白酶(Neutrase)作为改性用酶.通过单因素实验,分析了底物浓度,E/S,反应时间对水解度和氮收率的影响,并通过正交实验确定制备酶改性大豆分离蛋白(简称ESPI)的最佳工艺参数为:底物浓度为3%,E/S为1 200U/g,时间为60 min.得到的ESPI的蛋白含量与SPI相近,但NSI由SPI的90%提高到97%.而且在功能性方面,ESPI也得到了很好的改善,尤其是乳化性和起泡性.     

Structures and properties of chicken myofibrillar protein gel induced by microwave heating

Structures and properties of myofibrillar protein gel prepared at different power (300–800 W) were evaluated. Amino acid analysis demonstrated that changes in microwave power did not alter primary structure of gel. However, an increase in microwave power could change higher structures of gel. As microwave power increased, α-helix content decreased and β-sheet content increased. Increased microwave power probably facilitated protein to unfold and expose the internal groups, causing surface hydrophobicity and the formation of disulphide bonds were enhanced, which indicated changes in tertiary and quaternary structures of protein. At 500 W, gel had the best ultrastructure where surface morphology, springiness and water holding capacity reached the optimum. Our findings suggested that microwave at an appropriate power (500 W) could change higher structures of myofibrillar protein gel to achieve desired processing and quality protein gel characteristics.