物流运输对鱼类肌肉品质影响研究进展

现代物流运输技术高速发展,呈现智能化、信息化和高效化的趋势。通过物流运输可满足国内外消费者对鱼类产品多样性的需求,实现渔业资源优化配置。肌肉是鱼体主要食用部分,其品质直接影响产品加工适应性和经济价值。本文将鱼类产品分为鲜活、冰鲜和冷冻三大类,首先概述鱼类物流运输的方式、网络图和特点;其次,从营养价值、组织结构、风味特点、感官品质及物理性质五方面对鱼肌肉品质进行评价,并总结测定方法;最后,论述物流运输过程中温度、时间、包装等主要因素对鱼肌肉品质的影响。     

模糊数学评价和主成分分析电子束辐照处理后的鲈鱼品质

电子加速器放射出的β射线对食品具有杀菌和保鲜的作用。为系统评价电子束辐照剂量对鲈鱼品质的影响,对鲈鱼进行8个梯度剂量(0.00、2.45、3.33、4.41、5.27、6.64、7.24、8.56 k Gy)的辐照,然后通过感官评价和模糊数学矩阵来计算感官评价综合隶属度,并采用Pearson相关系数和主成分载荷分析确定鱼肉质构的主要代表因素。模糊数学感官评价结果显示,剂量越大,感官评价隶属度等级越低;辐照2.45、3.33、4.41 k Gy时,鱼肉样品感官评价的综合隶属度较接近1级。质构测定结果及主成分分析表明,咀嚼度、弹性和胶着度是辐照后鱼肉的质构代表因素,其值随剂量变化有所波动;剂量低于4.41 k Gy时,对鱼肉质构的影响无统计学差异(P0.05)。综上所述,电子束辐照剂量低于4.41 k Gy时,能最大限度保持鲈鱼肉产品感官品质和质构特性。     

抗冻剂对鱼肉蛋白质冷冻变性的保护作用

冷冻贮藏是一种广泛用于长期保存鱼肉及鱼肉制品的方法,而添加抗冻剂是抑制冻藏过程中蛋白质冷冻变 性、保持鱼肉品质的有效方式。本文简述了鱼肉蛋白质的冷冻变性机理,对目前行业领域内常用的糖类和糖醇类、 糖类降解物、多酚类、蛋白质水解物、盐类及抗冻肽等几种抗冻剂对鱼肉蛋白质的抗冻变性机理进行综述,并阐明 抗冻剂使用效果的影响因素及抗冻剂的应用及其局限,旨在为鱼类蛋白抗冻提供参考。     

莜麦山药鱼的加工工艺优化与质构分析

用马铃薯雪花粉代替新鲜马铃薯制作莜麦山药鱼(以下简称山药鱼),通过单因素实验和正交实验,考察各因素对莜麦山药鱼感官品质的影响,确定莜麦山药鱼的最佳配方和加工工艺。通过感官评分和质构分析,将本实验所得产品(以下简称改良产品)与传统产品进行比较,并初步分析冷冻对产品品质的影响。结果表明,改良产品的最佳配方为:莜薯比9∶1,食盐添加量2.0 g/100 g_(基础面粉),加水量为100 m L/100 g_(基础面粉)、葱花添加量为4.0 g/100 g_(基础面粉),水温90℃;改良产品较传统山药鱼有良好的感官和质构品质,短期冷冻过程对产品感官品质及部分质构特性影响不显著。     

不同冷冻工艺对龙头鱼品质的影响

以液氮冷冻、-80℃超低温冷冻与普通冰箱冷冻三种方式对龙头鱼进行冷冻处理,研究不同冷冻方式对龙头鱼p H、TVB-N、保水性等指标的影响,为龙头鱼的加工利用提供理论依据和技术指导。结果表明:经不同冷冻方式冷冻的龙头鱼p H、TVB-N、甲醛含量相差不大;样品的保水性能由高至低依次为-18℃组-80℃组液氮组;质构方面,龙头鱼在冷冻过程中其硬度、弹性和咀嚼性均有一定程度的下降,但液氮组下降的幅度最小;由感官评价可知,不同冷冻方式处理的天妇罗龙头鱼质地、可接受性等方面均有不同程度的下降,三种冷冻方式中液氮组天妇罗龙头鱼的感官综合评分比其他两组高。从冷冻品质综合考虑,选择液氮冷冻处理更有利于龙头鱼的品质。     

养殖大黄鱼冰点调节剂研制

研究冻结温度、冻结介质、鱼肉含水量及鱼块大小对养殖大黄鱼冻结过程中所产生的影响。在此基础上,考察NaCl、蔗糖、山梨醇、VC、葡萄糖对降低鱼块冰点所起的作用。通过Box-Behnken设计,结合鱼块冰点与感官品质变化,优化冰点调节剂的配方,最终选用2次挤压TPA方法对冰点调节剂处理前后的鱼肉质构特性进行测定。结果表明,相同冷冻温度和冷冻介质条件下,大黄鱼鱼块越小,含水量越低,鱼块降温越迅速。液体速冻比气体速冻具有更高的降温效率。通过Design-expert7.0软件确定的最佳冰点调节剂配方是:NaCl 5.16%,蔗糖2.96%,山梨醇7.15%。与空白对照组相比,将大黄鱼冰点从-1.5℃降低到-4.2℃,降低冰点作用明显,而鱼肉质构特性无统计学差异(P>0.05)。     

不同解冻方式对猪肉品质特性的影响

研究自然空气解冻、静水解冻、微波解冻和低温解冻4 种不同解冻方式对猪背最长肌肉品质特性的影响,分析猪肉解冻过程中食用品质特性、全质构特性、肌浆蛋白和全蛋白含量的变化。结果表明：冻结猪肉经静水解冻后,肌肉pH值接近6.0,解冻损失率和蒸煮损失率较低,静水解冻使猪肉的保水性维持较好。冻结猪肉解冻过程中肌浆蛋白和肌肉全蛋白浓度的变化对肉质构特性有显著或极显著影响。微波解冻有利于保持猪肉的嫩度和色泽,且通过微波解冻的冷冻猪肉其肌肉全蛋白含量较高,肉品的全质构特性较好。4 种解冻方法中,静水解冻和微波解冻能较好地保持解冻猪肉的品质。     

解冻方式及漂洗方法对冷冻竹荚鱼鱼糜品质的影响

探讨了解冻方式及CaCl_2溶液漂洗对冷冻竹荚鱼鱼糜加工品质的影响。实验中采用流水解冻、4℃空气解冻及微波解冻3种解冻方式,对解冻后竹荚鱼鱼肉盐溶蛋白含量、ATPase酶活以及其鱼糜凝胶的变化做了比较;同时以凝肢强度、持水性及微观结构为鱼糜品质的检测指标,考察了不同浓度CaCl_2溶液漂洗对冷冻竹荚鱼鱼糜凝胶特性的影响。结果表明:4℃空气解冻得到的鱼糜品质最好,流水解冻次之,但4℃空气解冻时间较长。CaCl_2溶液漂洗对冷冻竹荚鱼鱼糜的凝胶强度有较大影响,低质量分数的CaCl_2(<0.6%)漂洗可以增强冷冻竹荚鱼鱼糜凝胶强度,0.6%CaCl_2溶液漂洗时,凝胶强度最大,随后凝胶强度随CaCl_2质量分数增大而减小。     

高温蒸煮对鳙鱼块肌间小刺软化效果和质构品质的影响

以多肌间小刺的鳙鱼段为原料,以感官评定和质构为指标,研究经盐渍和热风干燥后,采用高温蒸煮处理对鱼肉肌间小刺软化的工艺条件。重点研究蒸煮温度、蒸煮时间、鱼块水分及盐分含量对高温蒸煮后的鳙鱼块肌间小刺软化效果和鱼肉质构品质的影响。结果表明:高温蒸煮温度、时间和鱼块水分含量为影响鱼肉肌间小刺软化和鱼肉质构品质的显著因素,盐含量影响不显著。经响应面优化,选择最佳高温蒸煮温度为126℃、时间26 min、水分含量48%,此时感官得分最佳,为9.89分。     

不同加工方式对鱼肉组织质地影响的研究进展

鱼类是一种风味独特、营养丰富并且平衡性很好的水产品,深受消费者喜爱。质构与食品的外观、风味、营养一起构成食品的4大品质要素。与畜肉相比,鱼肉的组织更加柔软细嫩,这主要和鱼肉的化学组成有关,随着人们生活水平的提高和食品加工业的发展,鱼肉的组织质地越来越引起人们的重视。本文介绍了几种质构参数,并从物理因素、化学因素和鱼体死后变化3方面分析了影响鱼肉组织质地的各种因素,其中主要介绍了鱼肉肌肉组织的蛋白质组成及其对质构的影响;重点综述了在水产品加工过程中不同加工方式如加热、冷冻、盐渍、烟熏等对鱼肉组织质地的影响,以期为质构分析在产品品质评定中的应用及即食产品的开发和生产提供一定的理论参考,进而更好地满足消费者的需要。     

乌珠穆沁羊生长过程中肌内结缔组织和肌纤维类型的变化

以1至18月龄乌珠穆沁羊骨骼肌中半腱肌(SD)和股二头肌(BF)为原料,采用组织化学法对肌纤维直径、肌内结缔组织和肌纤维类型的变化进行观察。结果显示,随着月龄的增加,SD和BF中肌纤维直径在1到9月龄之间呈增大趋势,12月龄时显著下降,之后呈上升趋势。SD和BF结缔组织中肌内膜总体呈增厚趋势。肌束膜在1到9月龄呈增厚趋势,到12月龄时有所下降,之后显著上升。随月龄的增加,SD和BF中Ⅰ型肌纤维的变化较大,在9和18月龄时呈下降趋势。SD中Ⅱa型纤维12月龄时百分比最低,而此时Ⅱb型纤维百分比最高。BF中Ⅱa型纤维百分比在1、9、18月龄之间以及3、6月龄之间差异均不显著(p>0.05)。Ⅱb型纤维在18月龄百分比最高。     

Rigor Tension Development in Excised "Rested", "Partially Exercised" and "Exhausted" Chinook Salmon White Muscle

Isometric rigorometry was used to study rigor tensions in "rested", "partially exercised" and "exhausted" chinook salmon ( Oncorhynchus tshawytscha ) white muscle at the pre-mortem acclimated temperature. Conservative handling and anaesthesia (AQUI-STM) minimized pre-mortem exercise and provided "rested" fish. Post-mortem electrical stimulation produced "partially exercised" (180 contractions) and "exhausted" (360 contractions) muscle. A "relaxation" stress that decreased with increasing exercise was measured. The amplitude of the "relaxation" and contraction stress was the same for each treatment (F_2,12= 0.24; p=0.79). Rigor contraction onset coincided with an intra-muscular pH of 6.6 in each treatment (F_2,12=0.28, p=0.76). Contraction stress abatement coincided with an "ultimate" pH of 6.2 in each of the treatments (F_1,12=0.05; p=0.83).     

金华火腿加工过程中的理化特性

以传统金华火腿为原料 ,跟踪测定了火腿加工全过程中半膜肌和股二头肌的水分、NaCl、非蛋白态氮 ,水溶性氮和游离氨基酸含量的变化情况。结果表明 ,半膜肌和股二头肌的水分含量逐渐降低 ;NaCl含量逐步上升 ,水溶性氮的含量在加工过程中先降低后升高 ,非蛋白态氮的含量也逐步上升。各种游离氨基酸随着加工的进行 ,含量逐渐增加 ,尤其是谷氨酸 ,金华火腿主要的鲜味物质 ,在加工过程中含量显著增加。     

Catechins enhance skeletal muscle performance

Abstract

Muscle-related disorders, such as sarcopenia and cachexia, caused by aging and chronic diseases can lead to the loss of muscle mass and strength to different degrees, severely affecting human health. Globally, tea is one of the three most popular beverages, and its major active ingredient catechins have been reported to delay muscular atrophy and enhance movement. However, currently, there is no systematic review to elaborate its roles and the associated mechanisms. This article reviews the (1) functions and mechanisms of catechins in the differentiation of myogenic stem cells, biogenesis of mitochondria, synthesis and degradation of proteins, regulation of glucose level, and metabolism of lipids in muscle cells; and (2) effect of catechins on the blood vessels, bones, and nerves that are closely related to the skeletal muscles. Catechins could prevent, mitigate, delay, and even treat muscle-related disorders caused by aging and diseases.     

Comparison of postmortem changes in goose cardiac and breast muscles at 5 °C

BACKGROUD: The tenderness of goose heart is an important consideration in its utilization as a popular meat product. It is generally thought that postmortem degradation of myofibrillar proteins may improved meat tenderness. Little information, however, is available regarding the postmortem changes in goose cardiac muscle. Therefore, the postmortem proteolysis between goose cardiac and breast muscles at 5 °C is compared. RESULTS: The pH is higher (P < 0.05) in cardiac samples than in breast samples. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis and western blots results indicate that postmortem degradation of titin and desmin and the appearance of the 28 and 30 kDa components are faster in breast muscle than in cardiac muscle. CONCLUSION: Our results may suggest that goose postmortem proteolysis occurs more rapidly in breast muscle than in cardiac muscle at 5 °C. Copyright © 2008 Society of Chemical Industry     

Phosphorus content of muscle tissue and muscle function in dairy cows fed a phosphorus-deficient diet during the transition period

Phosphorus (P) deficiency and hypophosphatemia are believed to be associated with muscle function disturbances in dairy cows, particularly around parturition. The objective of this study was to determine the effect of dietary P deprivation during late gestation and early lactation on muscle P homeostasis and muscle function in periparturient dairy cows. Thirty-six multiparous dairy cows in late gestation were randomly assigned either to undergo dietary P depletion or to be offered a diet with adequate P content from 4 wk before to 4 wk after parturition. Phosphorus-deficient rations for dry and lactating cows contained 0.15 and 0.20% P on a dry matter basis, respectively. Blood and muscle tissue for biopsy were obtained and electromyographic examinations were conducted on biceps femoris and intercostal muscles in regular intervals throughout the study. Muscle tissue was analyzed for the total P, adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, creatine phosphate, and tissue water content. Dietary P deprivation resulted in a pronounced and sustained decline of the plasma phosphate concentration, reaching a nadir at calving with mean values below 1.5 mg/dL and remaining below 2.0 mg/dL during the first 4 wk of lactation. Hypophosphatemia was not associated with signs of clinically apparent muscle weakness or disturbed muscle function and was not associated with a decline in the content of any of the studied P-containing compounds in muscle tissue. Accordingly, no association between plasma phosphate concentration and muscle tissue P content was found. Electromyographic examination identified subclinical effects on motor unit action potentials that are indicative of disturbed neuromuscular functionality. Increasing occurrence of pathologic spontaneous activity possibly resulting from membrane instability of nerve or muscle cells and suggestive of myopathy was also recorded as P deprivation progressed. These effects were predominantly observed in intercostal and to a lesser degree biceps femoris muscles. Electromyographic parameters affected by P deprivation were found to be associated primarily with the plasma phosphate and to a lesser extent with the amounts of energy storing P-containing compounds contained in muscle tissue. These results indicate that prolonged and pronounced dietary P deprivation in transition dairy cows leads to marked sustained hypophosphatemia without altering the muscle tissue P homeostasis or causing clinically apparent muscle function disturbances.     

Comparative studies of quality changes in white and dark muscles from common carp (Cyprinus carpio) during refrigerated (4 °C) storage

Differences between white and dark muscles from common carp (Cyprinus carpio) in sensory assessment, total viable counts (TVC), total volatile basic nitrogen (TVB‐N), pH, electrical conductivity (EC), biogenic amines (BAs), nucleotide degradation products and colours were investigated under air and vacuum conditions during refrigerated (4 °C) storage. Compared with white muscle, dark muscle had a higher lipid content, but lower crude protein and moisture content. TVC, TVB‐N, pH, and L* value were higher in white muscle, while K value and a* value were higher in dark muscle. Under both conditions, white and dark muscles had significant (P < 0.05) differences in tyramine and cadaverine content. Although dark muscle was significantly (P < 0.05) lower in ATP content, it had higher rate of IMP degradation and K value increase. Taking sensory and microbial indexes into consideration, dark muscle appeared to have a longer shelf life than white muscle under both conditions.     

肌纤维类型分类及转化机理研究进展

肌纤维作为骨骼肌的基本组成单位,其类型组成的差异与产肉动物的产肉量及其肉品的质量密切相关,故肌纤维成为近年来国内外的研究热点。本文先对肌纤维ATP酶染色法、免疫组化染色法等肌纤维类型的分类方法进行综述,进一步对肌纤维特性进行简要概述,最后回顾了肌纤维类型转化的外界因素及分子调控通路研究进展。以期为今后的肌纤维类型及转化机理研究提供参考。     

肌肉中多聚磷酸盐水解的研究进展

该文主要阐述了添加到肌肉中的多聚磷酸盐的水解及其影响因素的研究现状。三聚磷酸盐首先水解成焦磷酸盐和单磷酸盐,生成的焦磷酸盐进一步水解成单磷酸盐,添加的焦磷酸盐则直接水解成单磷酸盐。多聚磷酸盐在肌肉中主要是通过相应的水解酶水解,受到较多物理化学因素影响。