聚葡萄糖对罗非鱼鱼糜凝胶特性及蛋白结构的影响

以罗非鱼鱼糜为原料，添加聚葡萄糖，热诱导形成凝胶，通过测定凝胶强度、持水性、白度、水分分布、微观结构、蛋白质二级结构等指标，研究聚葡萄糖对罗非鱼鱼糜凝胶品质的影响。结果表明，随着聚葡萄糖添加量的增加，鱼糜凝胶强度、持水性增加，并在添加量4%时达到最大值；白度变化不明显；水分分布状态测定结果表明，聚葡萄糖的加入可以缩短鱼糜凝胶弛豫时间T2，改变不同种类水的分布状态，增强与水的结合；与对照组相比，添加聚葡萄糖的鱼糜凝胶网络结构更加致密，鱼糜凝胶中肌原纤维蛋白的α-螺旋结构减少，β-折叠结构增加。综合各项指标得出，添加适量的聚葡萄糖可以改善罗非鱼鱼糜的凝胶特性。该研究结果可为改善淡水鱼糜制品的品质提供理论依据。     

乳化大豆油与乳化猪油对肌原纤维蛋白/面筋蛋白凝胶的影响

为了改善蛋白凝胶的品质,研究不同比例的乳化大豆油与乳化猪油对肌原纤维蛋白/面筋蛋白凝胶的弹性、硬度、咀嚼性、持水性、可冻结水、非可冻结水、分子间作用力、蛋白二级结构的影响。结果表明：与对照组（未添加脂肪的凝胶）相比,随着乳化大豆油与乳化猪油添加量（5%-20%）的增加,肌原纤维蛋白/面筋蛋白凝胶的硬度、咀嚼性、弹性、胶粘性以及持水性均显著上升（p＜0.05）;可冻结水含量逐渐增加、非可冻结水含量逐渐降低;凝胶的疏水相互作用、氢键、二硫键作用逐渐增强,离子键作用逐渐减弱;蛋白二级结构由α-螺旋逐渐转化为β-折叠和β-转角。     

花椒水提物对鳜鱼鱼糜凝胶特性的影响

为探索花椒水提物（Zanthoxylum bungeanum aqueous extract,ZBAE）对鳜鱼鱼糜凝胶特性的影响,研究ZBAE添加量为0、0.125%、0.25%、0.5%和1.0%时,该鱼糜凝胶持水性、凝胶强度、质构、白度、二级结构和微观结构的变化。结果表明,随着ZBAE添加量增加,持水性、凝胶强度、硬度和胶着性指标均呈现先增强再减弱的趋势,并且在0.25%时均达到最大值;傅里叶红外光谱检测表明,ZBAE的添加使α-螺旋、β-折叠和无规则卷曲的相对含量值呈现先上升后下降的趋势,其中,添加量为0.125%和0.25%时,分别对应β-折叠和α-螺旋的最高值;扫描电子显微镜结果显示,ZBAE添加量为0.25%时,该凝胶网络结构更致密,分形维数、孔隙率和孔数量均显著优于未添加组（P<0.05）;此外,低添加量（<0.25%）的花椒水提物能够提高鱼糜凝胶的感官品质。因此,ZBAE具有改善鱼蛋白凝胶特性的潜力。     

谷氨酰胺转氨酶对鳜鱼鱼糜凝胶的品质影响

以鳜鱼鱼糜热诱导凝胶为研究对象，检测盐度、持水性、色泽、质构、感官评分、蛋白质二级结构、微观结构以及十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（sodium dodecyl sulfate-polyacrylamide gel electrophoresis，SDS-PAGE）指标。研究谷氨酰胺转氨酶（transglutaminase，TG）对其品质的影响规律。结果表明，TG可以提高鳜鱼鱼糜凝胶白度；与对照组相比，添加TG后，胶黏性、咀嚼性和回弹性都显著上升（P＜0.05）；随着TG添加量的增加，鳜鱼鱼糜凝胶的硬度显著增加（P＜0.05），当添加量为0.6 U/g时，持水性达到最大值。SDS-PAGE中主要蛋白条带随TG添加量的增加逐渐减弱。扫描电子显微镜照片中观察到添加TG后，鳜鱼鱼糜凝胶形成更加致密的网络结构。因此，添加TG能改善鳜鱼鱼糜凝胶的品质特性，且TG添加量为0.4 U/g和0.6 U/g时较为适宜。该研究结果可为鳜鱼鱼糜凝胶品质改进提供理论支撑。     

变性淀粉对白鲢鱼鱼糜凝胶特性和蛋白构象的影响

为了研究原木薯淀粉、羟丙基淀粉、乙酰化二淀粉磷酸酯和醋酸酯淀粉对白鲢鱼鱼糜凝胶特性和蛋白构象的影响,分析不同淀粉添加量条件下,白鲢鱼鱼糜白度、凝胶强度、持水性、质构特性、储能模量(G')、化学作用力、蛋白二级结构和微观结构的变化规律。结果表明,添加淀粉可以显著提高鱼糜凝胶的持水性。当其添加量为1%时,可提高鱼糜凝胶的白度、凝胶强度、硬度和咀嚼度,且羟丙基淀粉的改善效果最佳。流变学特性表明淀粉在鱼糜制品中起到非活性填料的作用。添加少量淀粉可阻碍氢键的形成,促进疏水相互作用及离子键的形成,诱导鱼糜蛋白的构象由α-螺旋结构向β-折叠结构转变。4种淀粉添加量为1%时均可以得到更为致密的鱼糜凝胶网络结构,其中,添加羟丙基淀粉可以使鱼糜凝胶网络中孔洞的大小、分布更均匀。添加1%的羟丙基淀粉可用于改善白鲢鱼鱼糜的凝胶品质。     

亚麻籽胶对儿茶素-肌原纤维蛋白热诱导凝胶特性的影响

向儿茶素-肌原纤维蛋白体系中添加不同质量分数的亚麻籽胶（0.1%～0.4%）,探究其对儿茶素与蛋白互作后凝胶强度、保水性、水合特征、流变特性及二级结构的影响。结果表明：亚麻籽胶添加量为0.1%时,凝胶强度最大;亚麻籽胶添加量0.4%、儿茶素含量100 μmol/g时,凝胶保水性最好;亚麻籽胶可提高凝胶束缚水的能力;最终形成凝胶时,储能模量G’随亚麻籽胶添加量的增加而增加;加入亚麻籽胶使凝胶中的α-螺旋含量增加,而β-折叠、β-转角和无规卷曲含量均降低。因此,亚麻籽胶可改善儿茶素对肌原纤维蛋白凝胶特性的不利影响。     

鱼骨粉对海鲈鱼肌原纤维蛋白凝胶特性的影响

以鳕鱼鱼骨粉及海鲈鱼肌原纤维蛋白为研究对象,采用球磨机制备微细鱼骨粉,测定其粒度、矿物质组成和微观结构,分析鱼骨粉对海鲈鱼肌原纤维蛋白凝胶的持水性、蒸煮损失、凝胶强度、白度、水分分布状态、蛋白分子量分布以及蛋白质二级结构的影响。结果表明:鱼骨粉钙、磷含量丰富,二者比例接近人体骨骼的钙磷比;随鱼骨粉添加量的增加,肌原纤维蛋白凝胶的持水性和凝胶强度均呈先上升后下降的趋势,白度值逐渐增大,蛋白二级结构中α-螺旋的保持增多;当鱼骨粉添加量为3%时,凝胶持水性和凝胶强度分别提高19.4%和95.23%,蒸煮损失降低27.5%,水分弛豫时间T23达到最小值43.3 ms,肌球蛋白重链(MCH)含量最高,凝胶效果最好。     

转谷氨酰胺酶对鲤鱼肌原纤维蛋白乳化活性和凝胶特性的影响

目的:研究添加转谷氨酰胺酶(Transglutaminase,TG)对鲤鱼肌原纤维蛋白乳化活性和凝胶特性的影响,为改善鱼糜制品的品质特性提供理论依据。方法:肌原纤维蛋白溶液浓度为40 mg/mL,TG添加量为蛋白溶液的0%、0.1%、0.2%、0.3%、0.4%(W/V),测定蛋白溶液的乳化活性及凝胶特性指标。结果:随着TG添加量的增加肌原纤维蛋白溶液乳化活性降低(p<0.05);TG添加增大了蛋白浊度(p<0.05);蛋白流变结果表明,随着TG添加量的增加显著增大储能模量(G')(p<0.05),降低起始凝胶温度,并提高蛋白变性温度;与对照相比,添加0.1%的TG会降低凝胶持水性,但是进一步增加TG对凝胶持水性影响不显著(p>0.05);添加TG显著降低了凝胶白度(p<0.05);凝胶质构测定结果显示,随着TG添加量的增加,会改进蛋白质的凝胶特性,显著增加凝胶弹性和硬度(p<0.05)。结论:肌原纤维蛋白中添加TG到能够降低蛋白的乳化特性,但会改进肌原纤维蛋白的凝胶特性。     

添加微细鲽鱼鱼骨泥对金线鱼鱼糜凝胶品质的影响

以鲽鱼骨为研究对象,首先采用湿法超微粉碎技术将其加工成微细骨泥,再将其添加到金线鱼鱼糜制品中开发高钙鱼糜制品,从鱼糜溶胶pH值、肌原纤维蛋白Ca2＋-ATP酶活力、凝胶强度、质构、持水性、色泽、凝胶溶解度、微观结构方面探讨添加不同质量分数（2.5%～12.5%）鱼骨泥对鱼糜制品凝胶品质的影响。结果显示：添加微细鱼骨泥不影响鱼糜正常凝胶的pH值;较低质量分数（不超过5.0%）时,鱼骨泥中的Ca2＋可以激活鱼糜溶胶中肌原纤维蛋白的ATP酶,显著提升Ca2＋-ATP酶活力;鱼糜凝胶的凝胶强度、质构、持水性、色泽指标均在添加质量分数5.0%鱼骨泥时达到最高值,而凝胶溶解度达到最低值。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析和扫描电子显微镜观察结果表明,添加质量分数2.5%～5.0%鱼骨泥一定程度上促进了肌球蛋白重链（myosin heavy chain,MHC）的交联,可以促进鱼糜凝胶形成致密均匀的网状结构,过量添加则会影响MHC交联和凝胶网络致密性。     

3种改性纤维素对低盐鱼糜-蟹肉混合凝胶品质的影响

目的 研究不同添加量(0.2%,0.4%,0.6%,0.8%,1%)的微晶纤维素(microcrystalline cellulose,MCC)、甲基纤维素(methyl cellulose,MC)和羟丙基甲基纤维素(hydroxypropyl methyl cellulose,HPMC)3种改性纤维素对低盐鱼糜-蟹肉混合凝胶品质的影响。方法 以白鲢鱼糜和性早熟中华绒螯肉为原料制备混合凝胶,用物性仪、离心法以及色差仪测定混合凝胶的凝胶强度、持水性和白度,并通过傅里叶红外光谱、化学作用力、总巯基含量以及扫描电镜分析原因。结果 低盐鱼糜-蟹肉混合凝胶添加0.2% MCC时,凝胶品质更好。凝胶强度、持水力得到了提高,白度也得到了改善。同时α螺旋结构展开,β折叠结构形成,疏水作用力增大,总巯基含量降低,二硫键含量升高,微观结构变得更加有规律,有利于混合凝胶网络结构进一步形成。结论 添加0.2%的MCC可以有效改善低盐鱼糜-蟹肉混合凝胶品质。     

Effect of laver powder on textual,rheological properties and water distribution of squid (Dosidicus gigas) surimi gel

In order to ameliorate the gel quality of Dosidicus gigas surimi, the effects of laver powder on gel properties, rheological properties, and water-holding capacity (WHC) were investigated. Results indicated that the addition of laver powder could significantly increase the hardness, chewiness, and breaking force of surimi gels. However, the texture indexes and gel strength began to decline when additional amount exceeded 0.6%. Rheological results demonstrated that the addition of laver powder increased the storage modulus (G′) and viscosity of surimi, prolonged protein denaturation temperature in surimi gels. Moreover, the WHC of surimi gel was improved with the increase of laver powder. Further analyses in low-field nuclear magnetic resonance revealed that laver powder could shorten the transverse relaxation time, enhanced the combination with water, and altered the distribution of different water categories. The proportion of bound water and immobilized water reached its maximum and minimum at 0.6% of laver powder, respectively. Correlation analyses showed that WHC of surimi gel was negatively correlated well with the proportion of loose-bound water, but positively correlated with the strong-bound water and free water. In conclusion, the results supported that 0.6% was the optimal additional amount of laver powder for the squid-based surimi production based on the current ingredients of surimi products.     

基于蛋白质结构和理化性质的鱼糜蛋白-油脂相互作用

通过添加不同质量分数大豆油和猪油，研究油脂对金鲳鱼鱼糜凝胶理化性质和蛋白结构的影响。在油脂质量分数范围内（0%～20%）,8%的猪油与大豆油使鱼糜白度、持水性、凝胶强度、储能模量（G’）和感官评价显著增加。而油脂质量分数高于8%后，鱼糜凝胶强度、持水性、G’等指标下降。与大豆油相比，含有猪油的鱼糜凝胶（8%）的指标更优。扫描电子显微镜结果显示，油脂不仅以颗粒填充的方式占据蛋白间的空隙，还在表面形成界面蛋白膜，通过蛋白丝与蛋白基质结合。研究表明油脂在鱼糜凝胶中所产生的作用是由油脂-界面蛋白膜-蛋白质共同作用而形成。拉曼光谱图谱表明，添加油脂会使蛋白质α-螺旋相对含量下降，β-折叠相对含量先上升后下降。而大豆油的加入，使得鱼糜凝胶的无规卷曲相对含量也明显增加，而猪油处理组中无规卷曲相对含量变化不如大豆油组。大豆油和猪油的添加均导致鱼糜凝胶的蛋白侧链疏水基团暴露。这些结果表明油脂的存在会改变鱼糜蛋白的微环境和分子结构，进而影响鱼糜凝胶的理化性质。当猪油质量分数为8%时，鱼糜凝胶表现出更优的性质。     

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.     

百香果皮粉对非漂洗罗非鱼鱼糜凝胶品质的影响

以非漂洗罗非鱼鱼糜为对象,研究添加百香果皮粉（1%、2%、3%、4%、5%）对非漂洗罗非鱼鱼糜白度、凝胶全质构、凝胶强度、持水性、蒸煮损失率以及水分迁移的影响。结果表明,随着百香果皮粉添加量的增加,鱼糜硬度、凝胶强度、持水性增加,并在添加量为4%时达到最大值,随后硬度、凝胶强度、持水性开始下降,而蒸煮损失率呈先下降后上升的趋势,白度值降低。低场核磁共振结果表明,百香果皮粉的加入使鱼糜凝胶中水分状态发生变化,结合水和不易流动水比例增加,自由水比例减少,且添加量为4%时变化最为显著。综合各项指标得出,添加4%百香果皮粉有利于提高非漂洗罗非鱼鱼糜的凝胶品质。     

Nano eggshell calcium enhanced gel properties of Nemipterus virgatus surimi sausage: gel strength,water retention and microstructure

The effects of nano eggshell calcium (NEC) at different levels (0–1.5 g/100 g) on the gel properties of Nemipterus virgatus surimi were investigated. The results indicated that under the condition of adding 1.0 g/100 g, the gel strength of surimi was the highest, the water-holding capacity (WHC) was the best, and the cooking loss was the lowest. Sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the addition of NEC promoted the covalent cross-linking between myosin heavy chains (MHC). Raman spectroscopy demonstrated that low contents (0.5–1.0 g/100 g) of NEC promoted the conformational transition of surimi protein from α-helix to β-sheet. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) showed that the surimi gel with 1.0 g/100 g NEC had a denser network structure. Nevertheless, in the mixed gel with 1.25–1.5 g/100 g NEC, the network structure of the mixed-protein matrix was disrupted, and the mechanical and physicochemical parameters were deteriorated.     

The effect of sodium tartrate and sodium citrate on quality changes of squid (Dosidicus gigas) surimi gel

The yield of squid has grown gradually; however, the lack of intensive processing has led to the slow development of the squid industry. In a previous study, some organic salts were found to improve the quality of squid surimi gel. Therefore, this research focused on the effects of sodium citrate (SC) and sodium tartrate (ST) on the quality of squid surimi gel. Physical measurements, such as gel texture, water-holding capacity, and color of squid surimi gel, were conducted. The addition of 2.5% SC and ST significantly improved the gel strength by 40.7, 57.0, 22.9, and 58.1%, respectively, of gel strength compared with the addition of: 1.5 SC, 3.5 SC, 1.5 ST, and 3.5% ST alone. Rheological measurements revealed that the addition of 2.5% SC or ST shortened the gel degradation temperature range (i.e., 2.5% SC or ST: 40–53°C; other treatments: 40–60°C) of the squid paste during heating. Results of chemical force analysis showed that the addition of a high quantity of salt accelerated protein aggregation and reduced hydrophobic interactions and disulfide bond formation. Finally, an increase in the number of β-sheets and a decrease in the bulk water content demonstrated that the addition of 2.5% organic salt could form squid gel with a better network structure. The findings provide a scientific basis for the development of high-quality squid surimi gel.     

超高压对带鱼鱼糜凝胶特性及其肌原纤维蛋白结构的影响

以带鱼鱼糜为原料,分别采用不同的超高压参数和热处理,分析鱼糜凝胶强度、白度、质构指标、微观结构以及肌原纤维蛋白含量和构象单元的变化,探究超高压处理对带鱼鱼糜凝胶特性及其肌原纤维蛋白结构的影响。结果表明：超高压诱导带鱼鱼糜凝胶网络结构形成,超高压诱导组质构特性、凝胶强度、白度均比对照组有所提高,扫描电子显微镜图显示350 MPa保压8 min后（350-8组）所形成的鱼糜凝胶网络结构与热诱导组接近;超高压处理后,鱼糜凝胶中的肌原纤维蛋白含量有所降低,经圆二色光谱测定,肌原纤维蛋白的两个负峰逐渐消失,其α-螺旋结构相对含量下降,无规卷曲和β-折叠的相对含量有不同程度上升,350-8组无规卷曲相对含量与热诱导组接近。综上,适宜的超高压处理条件（350 MPa保压8 min）显著影响带鱼鱼糜凝胶特性及其肌原纤维蛋白二级结构,促进凝胶网络形成,改善鱼糜凝胶品质。     

油茶籽油对鱼糜凝胶特性及凝胶结构的影响

为探讨脂质对鱼糜蛋白凝胶功能特性的影响及其机理,研究不同油茶籽油添加量对鱼糜凝胶特性、水分分布、脂质及蛋白质结构等的影响。结果表明:随着油茶籽油添加量的增加,鱼糜凝胶强度、乳化稳定性和持水性显著增加(P0.05),当油茶籽油添加量增加到8%时各指标基本稳定,此时鱼糜凝胶强度为225.1 g·cm,游离出来的液体质量分数为2.60%。拉曼光谱分析发现,油茶籽油的添加改变了鱼糜凝胶体系中脂质和蛋白质的化学结构,主要表现为C—H谱带峰宽的增加、O—H谱带相对强度的下降,以及鱼糜蛋白中β-折叠、β-转角和无规卷曲结构相对含量的增加和α-螺旋结构相对含量的降低。同时,随着油脂质量分数的增加,水分以更加细小的状态分布在鱼糜凝胶体系之中。以上结果进一步揭示了油茶籽油的添加可增加鱼糜凝胶强度、乳化稳定性和持水性的内在原因。