Effects of water,Na^+ and Ca^(2+) on stress-relaxation properties of surimi gel

Surimi gel was made from silver carp(hypophthalmichthys molitrix).Texture analyzer was adopted to measure stress-relaxation curve to study the effects of water,Na+ and Ca2+ on relaxation properties of surimi gel,so as to provide the basic data for development of surimi gel products.Micromodel of gel based on continuous phase of protein network with water embed and dispersed phase of myofibril was established.Stress-relaxation properties of the gel were imitated by use of five-element relaxation mathematical model,with high fitted precision.The results show that addition of water can reduce hardness of gel;Na+ and Ca2+ can improve the viscoelasticity of gel.

Effects of Alginate Gel on Rheological Properties of Hair-tail (Trichiurus lepturus) Surimi

Effects of alginate gel at different concentrations on rheological properties of hair-tail (Trichiurus lepturus) surimi were investigated. Alginate gel (1% - 3%) exhibited enhanced effects, especially when alginate gel concentration increased. The rheological properties of mixture samples were studied by the time sweep, frequency sweep and temperature sweep. The critical strain values of the mixture samples for the onset of non-linear viscoelasticity were about 5%. The storage modulus G' of the mixture samples increased with time for 4 h. The frequency sweep showed that G' was greater than G" for all the mixture gels with different alginate gel concentrations, and values of both n' and n" for all samples were low (<0.2), these constants corresponding to G' and G", and indicating the elasticity of mixture gels. The values of storage modulus G' decreased during heating process and increased with decreasing temperature.

Effect of Water Chestnut Powder on Gel Properties of Silver Carp Surimi

[Objectives]The effects of water chestnut powder on the gel properties and quality of silver carp surimi were investigated.[Methods]The surimi gel was prepared by adding 0%,1%,2%,3%,4%and 5%of water chestnut powder to the surimi of silver carp.The gel properties,water-holding capacity,cooking loss,whiteness value,puncture and texture profile analysis(TPA)indexes of surimi products were determined to assess the effects of adding different amounts of water chestnut powder on surimi gel.[Results]The results showed that the gel strength,breaking force and depression distance of surimi products increased first and then decreased with the increase of the addition of water chestnut powder.Compared with the control group,the hardness and chewiness of surimi gel in TPA could be significantly improved by adding water chestnut powder.When the addition of water chestnut powder was 2%,the maximum water-holding capacity was 83.68%;the cooking loss rate was the lowest;and the whiteness value was the highest.Adding 2%of water chestnut powder could significantly improve the gel properties of silver carp surimi and obtain a good gel product.[Conclusions]This study provides a scientific basis for the effective utilization of water chestnut resources and the development of new fish surimi products.

Enzymatic Hydrolysis of Hairtail Surimi in an Ultra-High Pressure Bioreactor

Amino acids have been extracted from Hairtail surimi using enzymes in an ultra-high pressure bioreactor. The extraction efficiency of different enzymes including papain, trypsin, and proteases (acid, neutral, alkaline) also has been evaluated, and it has been discovered that neutral protease behaved the best. The amino acids were analyzed using automatic amino acid analyzer, and the enzymatic digestion conditions were optimized. For neutral protease, the optimal condition was 50℃, 250 MPa, pH 7.0. Material to liquid ratio of enzyme is 6%. More than 29 amino acids were detected after 24 hours of hydrolysis;the enzymatic hydrolysis rate can reach 83.29%. The results show that enzymatic digestion under ultra-high-pressure provides a very promising approach to extract amino acids from Hairtail surimi.

Effect of Tea Polyphenols on Lipid Oxidation of Nemipterus VirgatusSurimi Cake During Ice Storage

Surimi cake is a high value aquatic product. In this work, lipid oxidation and volatile compounds in Nemipterus virgatus surimi cake were investigated to evaluate the effectiveness of tea polyphenols in preventing or reducing lipid oxidation. Surimi cake was prepared in the presence or absence of 0.2% tea polyphenols, and was stored at 4 ℃ for 16 days. It was found that the peroxide value(POV) and thiobarbituric acid reactive substances(TBARS) values of the experimental groups(with 0.2% tea polyphenols) were much lower than those of the untreated surimi cake(p<0.05). In total, 52 compounds were presented in the volatiles of the surimi cake, such as ethanol, hexanal,(E,E)-2,4-decadienal, 2,3-octanedione, 2-hydroxy-propanamide, and 2,5-dimethyl-pyrazine. It indicated that tea polyphenols could reduce the amount of hexanal, ethanol, and(E,E)-2,4-decadienal, and delay the lipid oxidation of the surimi cake. Effects of lipid oxidation of the tea polyphenols on surimi cake were reduced during storage in ice.

Effects of Huangzhou Radish Powder on the Quality of Silver Carp Surimi Products

[Objectives]This study was conducted to improve the quality of frozen silver carp surimi products.[Methods]Huangzhou radish powder and silver carp surimi were used as raw materials to analyze the effects of different amounts(1%,2%,3%,4%,5%)of Huangzhou radish powder on the water-holding capacity,cooking loss rate,whiteness value,TPA,gel strength and sensory quality of surimi products.[Results]When the addition amount of Huangzhou radish powder was 1%,water-holding capacity,hardness,chewiness and the gel strength of the surimi product reached their maximum values,which were 86.86%,3470.36 g,2628.50 g and 707.48 g·mm,respectively.Meanwhile,the cooking loss rate was reduced to a minimum value(13.66%),and the sensory quality reached the best.The whiteness of surimi products showed a decreasing trend with the increase of the addition amount of Huangzhou radish powder.However,the whiteness of the surimi product was not significantly affected when the addition amount of Huangzhou radish powder was 1%.Therefore,when the addition amount of Huangzhou radish powder was 1%,the quality of surimi products could be improved.[Conclusions]This study provides a new idea for the development and utilization of Huangzhou radish.

Effects of Supplemental Amount of Tuanfeng Lotus Seed Powder on Quality of Silver Carp Surimi Products

[Objectives]This study was conducted to improve the gel properties of freshwater surimi and its products. [Methods] Tuanfeng lotus seed powder was added to frozen silver carp, and the relationship between the addiamount of Tuanfeng lotus seed powder(1%, 2%, 3%, 4% and 5%) and the quality of surimi products was studied, so as to improve the quality of surimi products. [Results] The water holding capacity(86.71%±0.36%), hardness(3 566.64±51.15) g, chewiness(2 697.16±15.81) g and gel strength(692.54±23.19) of surimi products increased to the maximums when the addition amount of lotus seed powder was 3%. Meanwhile, the cooking loss rate was reduced to the minimum(13.00%±0.17%), and the sensory quality was the best, although the whiteness of surimi products decreased slightly with the increase of Tuanfeng lotus seed powder. Therefore, the quality of silver carp surimi products could be improved obviously when the dosage of Tuanfeng lotus seed powder was 3%. [Conclusions] This study provides more new ideas for improving the quality of silver carp surimi products, and simultaneously makes the development of lotus seed food more diversified.

外源物质对低盐罗非鱼糜蛋白构象及体外消化特性的影响

以微波超声波辅助制备的低盐罗非鱼糜凝胶为研究对象,分析谷氨酰胺转氨酶(TGase)、羟丙基二淀粉磷酸酯(HDP)、结冷胶和三者的复配物(THG)对其水分分布及蛋白质构象的影响;并通过体外模拟消化实验,探究不同外源物质对微波超声波辅助制备的低盐罗非鱼鱼糕体外消化特性的影响。结果表明:添加THG后,鱼糜结合水和不易流动水较空白组分别增加98.71%和14.75%,自由水含量显著减少(P<0.05);THG促进了α-螺旋向β-折叠、β-转角和无规则卷曲结构转化。与空白组相比,添加0.4%TGase和THG对低盐罗非鱼糕的胃排空速度、蛋白体外消化率及蛋白水解度均有正面作用;其中THG可显著促进蛋白质分解成粒径较小的聚集体(P<0.05),经胃-十二指肠消化结束后的消化产物颜色更加透明清晰,从激光共聚焦显微镜可观察到THG组的红色荧光亮点显著减少,反映其蛋白被消化得较为完全。由此可见,在THG的作用下,鱼糜中水分子与蛋白质结合更紧密,相对于单一的外源物质,THG更加明显地改变了蛋白质的构象,且更有利于疏水蛋白基团的暴露和蛋白间的相互作用,且对鱼糕的消化有促进作用。本研究的结果为罗非鱼糜凝胶特性研究及罗非鱼糕类食品的开发与应用提供理论参考。

Comparisons of the Properties of Whitemouth Croaker (<i>Micropogonias furnieri</i>) Surimi and Mechanically Deboned Chicken Meat Surimi-Like Material

The aim of this work was to evaluate and compare the color, texture and sensory characteristics of whitemouth croaker (Micropogonias furnieri) surimi and mechanically separated chicken meat (MDCM) surimi-like material (SLM). The whiteness of the MDCM-SLM was higher (P > 0.05) than that from the surimi. Higher breaking force (P < 0.05) and gel strength (P < 0.05) were also observed for the MDCM-SLM when compared to the surimi. The deformation did not vary significantly for these two products (P > 0.05). The MDCM-SLM was more accepted by the panelists (P < 0.05). The mean scores of overall desirability for MDCM-SLM was similar to that observed for walleye Pollack surimi that is the parameter of quality. The differences in the acceptability of poultry and fish food products are probably due to peoples’ eating habits.

臭氧水处理对罗非鱼鱼糜品质及体外消化特性的影响

将臭氧水漂洗的罗非鱼鱼片制成鱼糜,研究漂洗质量浓度和漂洗时间对鱼糜品质和体外消化特性的影响,并通过分析肌原纤维蛋白氧化程度探讨臭氧水漂洗提高罗非鱼鱼糜品质的原因。结果表明,臭氧水漂洗后鱼糜白度、硬度和胶着度显著提高(P<0.05),10 mg/L臭氧水漂洗10 min时鱼糜的凝胶特性最佳。随着臭氧水漂洗质量浓度的增加和漂洗时间的延长,鱼糜硫代巴比妥酸反应物值呈上升趋势,肌原纤维蛋白的羰基含量上升、总巯基含量逐渐降低。感官评价结果显示10 g/mL臭氧水漂洗10 min时感官品质最佳。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳图谱显示,10~18 mg/L臭氧水漂洗使蛋白交联形成较小的可溶性聚集体,大于18 mg/L臭氧水漂洗后蛋白形成较大的不溶性聚集体。根据拉曼光谱结果可知,10~18 mg/L臭氧水漂洗使肌原纤维蛋白二级结构逐渐展开,α-螺旋逐渐转化为β-折叠和无规卷曲。体外消化结果表明,臭氧水漂洗提高了鱼糜在消化过程中的水解程度,其中10 mg/mL臭氧水漂洗10 min时水解程度最高,消化后小分子肽(100~1000 Da)含量显著高于其他实验组(P<0.05)。综上所述,肌原纤维蛋白适度氧化能提高罗非鱼鱼糜的品质,10 mg/mL臭氧水漂洗10 min时,鱼糜感官品质最好,凝胶特性及体外消化特性最佳。

基于GC-IMS分析采肉次数对鱼糜风味特征的影响

为阐明采肉次数对鱼糜风味特征的影响,本研究采用GC-IMS测定不同采肉次数下(1、2、3、4和5)制备的白鲢鱼糜的挥发性物质,同时测定TBARS值,并对它们进行相关性分析。结果显示:5组鱼糜中检测出的挥发性物质均为58种,其中壬醛、乙酸乙酯、2-丙酮、乙醇、2-甲基丁醛的含量相对较高;醛(39.13%~40.91%)、酮(15.52%~21.74%)、醇(19.28%~26.59%)是主要的挥发性物质种类。随着采肉次数的增加,醛类占比先下降后升高,酮类占比逐渐上升,醇类占比波动变化。挥发性物质的PCA和欧式距离结果表明,采肉次数为1制备的鱼糜样品和其它样品的风味特征差异明显。增加采肉次数,鱼糜的TBARS值先显著(P<0.05)增加后显著(P<0.05)降低。鱼糜中己醛、戊醛、E-2-戊烯醛、E-2-辛烯醛、3-辛醇,2,3-戊二酮等与TBARS值正相关(0.8>r>0.5),苯酚、苯乙醛负相关(−0.8<r<−0.5)。采肉次数影响鱼糜风味特征,其主要原因可能是与脂肪氧化有关。

发酵鲢鱼鱼糜香肠加工工艺优化及品质分析

以混合菌种(清酒乳杆菌、木糖葡萄球菌)作为发酵剂,以感官评分和pH为指标,采用正交实验优化发酵鲢鱼鱼糜香肠的加工工艺,并对产品进行指标测定。结果表明,当发酵剂接种量为3%,在30℃下发酵18 h时,所得产品香味浓郁,组织紧密,色泽均匀,口感良好,无异味。与未发酵香肠对比,在此条件下制得的发酵香肠的pH显著降低,氨基酸态氮含量升高,产品的色泽和质地得到明显改善,风味物质增加,尤其是芳香化合物和醇类化合物。该研究为发酵鱼糜制品的深入研究提供了一定的理论基础,为工业化生产提供了参考。

淡水鱼鱼糜凝胶品质影响因素的研究进展

我国淡水资源十分丰富,淡水鱼产量和养殖量均居世界首位。目前,淡水鱼的消费以“鲜活销售”和“家庭烹饪”为主,深加工比例较低,以鱼丸、鱼豆腐、鱼糕和鱼肠等为代表的鱼糜制品,因其内源性蛋白酶含量较高,在加工中易发生凝胶劣化现象。与海水鱼鱼糜相比,淡水鱼鱼糜的凝胶性较差,因此,提升淡水鱼鱼糜的凝胶性成为目前炙手可热的研究方向。文章基于淡水鱼糜凝胶的形成机理,主要综述了加工工艺、热诱导方式和外源物质添加对淡水鱼鱼糜凝胶品质的影响,为提高淡水鱼鱼糜凝胶品质奠定了理论依据。

枸杞粉对白鲢鱼糜凝胶品质的影响

该研究以冷冻白鲢鱼糜为实验原料,向其中添加枸杞粉(wolfberry powder,WP),分析不同添加量[0.25%、0.5%、0.75%、1%、1.5%(质量分数)]的WP对白鲢鱼糜凝胶持水性、蒸煮损失率、白度值、水分分布、凝胶特性、微观结构、感官评价及气味特征的影响。结果表明,随着WP含量的增加,鱼糜凝胶的持水性、硬度、咀嚼性和凝胶强度都表现出先增大后减小的趋势,当WP的添加量为0.5%时达到最大,分别为78.55%、(2716.77±75.76)g、(2185.15±32.46)g和1087 g·cm;而蒸煮损失率则表现出先减小后增大的趋势,在0.5%的添加量时,蒸煮损失率最小,为7.49%。在鱼糜中加入WP后,可以减少鱼糜凝胶中自由水的比例,增加不易流动水的比例,使鱼糜凝胶保留更多水分,且当WP在最适添加量0.5%时,鱼糜凝胶中只检测到结合水和不易流动水,未检测到自由水。适量WP的添加会增强鱼糜凝胶的网络结构,使其变得更加致密均匀。WP的添加会减小鱼糜凝胶的白度值和色泽评分,但在最适添加量0.5%时,其颜色总体可接受。此外,感官评价和电子鼻分析结果表明,当WP在最适添加量0.5%时,可以显著改善鱼糜凝胶的风味品质。研究结果可为生产高品质的鱼糜产品提供理论依据。

ε-聚赖氨酸对鲜鲅鱼糜冷藏保鲜过程中品质变化的影响

为探究ε-聚赖氨酸(ε-PL)对鲜鲅鱼糜冷藏保鲜过程中品质变化的影响,测定了添加ε-PL后鲜鲅鱼糜在4℃贮藏1、2、3、5、7天的氧化指标、微生物指标和凝胶品质指标。结果表明,对照组鱼糜样品在冷藏保鲜过程中的综合品质明显下降,其中总巯基含量迅速上升、丙二醛含量快速下降,且菌落总数在第5天时已经超标。而ε-PL的添加(特别是添加量达到0.03%)有效抑制了蛋白质和脂肪的氧化,并使鲜鲅鱼糜的二级鲜度保持期延长了5天、货架期延长了2天,同时提升了产品白度。但过量添加ε-PL对鱼糜制品的凝胶强度、持水性、硬度以及咀嚼性产生了一定负面影响。本试验结果可为鲜鲅鱼糜冷藏条件下的货架期延长和鱼糜制品的品质控制提供一定理论依据和参考。

马铃薯基乳液对鱼糜凝胶品质的影响

为了研究马铃薯基乳液(PE)对鱼糜凝胶品质的影响,实验采用玉米油(CO)或PE按不同添加量(0%~14%)与鱼糜混合,以鱼糜凝胶质构、水分、色泽、分子间相互作用、流变特性和微观结构为考察指标,探究PE作为脂肪替代物对鱼糜凝胶品质的影响及机理。结果显示,在相同的油添加量下,与CO相比,PE能避免油滴对鱼糜凝胶质构特性和持水能力产生的劣化效果,使样品表现出更高的弹性模量和黏度;另外,横向弛豫时间结果显示,PE抑制了不易流动水向自由水的转变,使更多的不易流动水被束缚,这可能增强了光线漫反射,从而使PE样品白度更高。微观结构和分子间作用力测定结果显示,PE样品中油滴分布更均匀,氢键、疏水相互作用和二硫键更强,凝胶网络因淀粉颗粒的填充效应而更致密。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳结果表明,PE组中油滴对鱼糜蛋白交联的干预程度更小。研究表明,PE可作为脂肪替代物提升鱼糜凝胶制品品质。本研究可为淀粉基脂肪替代物的开发及其在鱼糜凝胶产品中的应用提供理论基础。

植物乳植杆菌通过抑制蛋白水解改善罗非鱼发酵鱼糜凝胶强度

利用微生物发酵能有效改善淡水鱼鱼糜的凝胶强度。罗非鱼鱼糜的凝胶强度低且在加工过程中易出现凝胶劣化。为开发高品质的罗非鱼发酵鱼糜制品,以植物乳植杆菌(Lactiplantibacillus plantarum)为发酵菌株,探究了加菌发酵对罗非鱼发酵鱼糜凝胶强度的影响。结果表明,加菌发酵能够显著改善罗非鱼发酵鱼糜的凝胶强度,降低大部分游离氨基酸以及总氨基酸的含量。采用16S rRNA高通量测序技术研究加菌发酵对罗非鱼发酵鱼糜中微生物菌群的影响,结果显示,加菌发酵鱼糜中乳植杆菌属一直为优势菌属,到发酵末期增至63.71%,而其他腐败微生物菌属的丰度显著下降,同时菌落总数明显低于自然发酵鱼糜。构建了不同发酵时期的相关性网络图,结果表明在整个发酵期凝胶强度与菌落总数和总氨基酸含量呈显著负相关,仅乳植杆菌属与菌落总数和总氨基酸含量呈显著负相关,而与凝胶强度呈显著正相关。研究表明,植物乳植杆菌可以通过抑制腐败微生物的生长以及对蛋白质的水解作用来改善罗非鱼发酵鱼糜的凝胶强度。植物乳植杆菌可以作为专用发酵剂开发高品质罗非鱼鱼糜发酵制品。

氯化钠对鲢鱼糜体系3D打印性能及凝胶特性的影响

目的:提高鲢鱼糜体系3D打印性能及凝胶特性。方法:通过优化3D打印参数,将3D打印过程与材料流变性质及3D打印性能关联起来。探究氯化钠添加量对鲢鱼糜的流变性能、3D打印性能、凝胶强度、水分特性以及微观结构的影响。结果:氯化钠的加入以剂量依赖的方式降低了鲢鱼糜的耗散模量,但能显著提高材料的剪切恢复性能,还可以降低鱼糜体系的蒸煮损失,提高鱼糜体系的持水性。当氯化钠添加量为2.5%时,鲢鱼糜具有最佳凝胶强度和最为致密的微观结构。结论:添加适量氯化钠可提高鱼糜产品的3D打印性能和凝胶特性。