鱼类保活运输的研究进展

文中对目前国内外常用的净水法、增氧法、降温法和麻醉法等鱼类保活运输方法进行了综述,介绍了鱼体体质、暂养、水质和外力胁迫等因素对鱼类保活运输质量的影响,从行为和生理方面阐述了运输过程鱼类产生的应激反应及其相应的研究方法。文章最后分析了鱼类保活运输存在的问题,并对其发展前景进行了展望。     

鱼类保活运输技术研究进展

该文对化学方式（间氨基苯甲酸乙酯甲磺酸盐、丁香酚和二氧化碳等）和物理方式（降温、电击等）两类鱼类保活预处理技术进行分析和比较,介绍有水和无水两种运输形式,并从氧化应激、免疫反应和能量代谢3个方面简述鱼类在运输过程中发生的应激反应,总结目前在鱼类保活运输技术方面的研究进展,旨在为鱼类的保活运输研究提供参考。     

鱼类保活运输中应激反应诱发因素及其影响研究进展

在分析鱼类运输应激反应的基础上,综合血液生化指标、非特异性免疫细胞、抗氧化功能等,从低氧胁迫、氨氮胁迫、密度胁迫、客观运输条件胁迫、温度胁迫等运输中可能产生不同胁迫的角度,详细综述鱼类保活运输中应激反应诱发因素及其影响。     

鱼类保活及运输方法的研究进展

结合鱼类保活运输中的主要因素(温度、水质、监控措施和鱼的自身体质等),详细阐述了活鱼运输的几种方法(尤其是模拟冬眠运输法),列举了几种常用麻醉剂的使用及优缺点。同时提出鱼类保活运输中亟待解决的问题,并对保活技术的发展趋势进行了预测。     

运输应激对鱼类生理特性和肌肉品质影响的研究进展

应激反应是生物界中普遍存在的一种生理反应,它会直接影响生物的代谢过程和理化状态,并可能对动物的肌肉品质造成不利影响.运输是鱼类生产过程中必不可少的中间环节,也是引发鱼体应激的重要原因.因此,本文结合已有文献中应激对鱼类生理特性、肌肉品质以及代谢的影响,同时对应激状态下运输如何影响肌肉品质代谢途径进行讨论,并列举目前缓解...     

鱼类有水保活运输的研究进展

活鱼运输过程中要提高存活率,保障鱼类的品质与食用安全性。本文介绍了影响鱼类有水保活运输的主要因素,并对目前国内外常用的物理法、麻醉法、保活剂保活法等鱼类保活运输方法进行综述。文章最后介绍了有水保活运输存在的问题,并对其发展前景进行了展望。     

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...     

低温保活运输对海鲈鱼应激及品质的影响

以海鲈鱼为研究对象,探讨低温保活运输对其血液生化和肌肉理化指标的影响。首先分别测定温度、盐度、密度和暂养时间对海鲈鱼运输存活率的影响;其次,将海鲈鱼以3 ℃/h的降温速率降温至保活运输温度12,16 ℃和20 ℃,以室温下不运输的海鲈鱼为对照组,分别在模拟运输第12,24,36,48,60,72 h和运输结束恢复12 h后测定水质、血液生化和肌肉理化指标。结果表明:在温度12 ℃、盐度16‰、鱼水比1 ∶ 10~1 ∶ 8、暂养时间36 h条件下,保活运输后海鲈鱼的存活率最高。在整个保活运输过程中,水质随温度的升高呈显著下降趋势(P＜0.05)。血清乳酸脱氢酶、谷草转氨酶和谷丙转氨酶活性以及皮质醇水平显著升高(P＜0.05),血糖和应激蛋白呈先升高后降低的趋势。运输结束恢复12 h后, 12 ℃组海鲈鱼应激蛋白、乳酸脱氢酶、谷草转氨酶和谷丙转氨酶活性恢复至对照组状态。肌肉中总蛋白和乳酸水平呈显著上升趋势, 肌糖原、硬度和咀嚼性显著降低(P＜0.05),保活运输前、后海鲈鱼肌肉pH值、持水力和弹性无显著性变化(P＞0.05)。海鲈鱼长途运输的最佳保活温度为12 ℃。该研究结果为海鲈鱼及其它海水鱼类的保活运输提供参考。     

鲍鱼保活运输技术研究进展

消费市场与养殖环节的双重需求使鲍鱼保活运输具有非常广阔的应用前景。文章简要介绍鲍鱼保活运输的机理与方法,综述目前鲍鱼保活运输的研究进展与应用现状,分析目前应用中存在的问题并对研究发展方向做出展望。     

水产品低温保活运输研究进展

随着国家对鲜活水产品销售的重视,以及市场对其供不应求的加剧,必将对保活运输技术提出严峻的挑战.然而,低温保活运输是一种低成本、高存活率、长时间、高品质,且优于其它相关技术的绿色保活方法.简要综述了低温保活运输的主要影响因素、保活原理、低温对水产品生理的影响、及在保活运输上的应用,分析了水产品低温保活运输存在的问题,并对其前景进行展望.     

市售纳豆产品中菌株的分离、鉴定及纳豆激酶活力比较

为考察不同品牌纳豆中纳豆芽孢杆菌的异同,本研究选取了三个产地六个品牌的纳豆产品作为试材,分别是日本的北海道、御城、竹炭、木场水户纳豆,北京的燕京纳豆和大连的美屋纳豆。从这六种品牌的纳豆中分离纯化得到了15个具有纳豆芽孢杆菌典型菌落特征的单菌落,并且与模式菌株1.1086株分别从菌落形态、菌株的细胞形态和生理生化实验以及16S rRNA序列分析四个方面进行对比鉴定。结果表明,这15株芽孢杆菌都为纳豆芽孢杆菌,其中10株与模式菌株的16S rRNA序列有99%的同源性,3株是98%,2株是97.5%。并且对挑选出的15株纳豆芽孢杆菌采用琼脂糖-纤维蛋白平板的方法测定纳豆激酶的活性,结果表明NB-8和NB-12具有较高的纳豆激酶活性,酶活力分别达到了1076.663 U/m L和1073.85 U/mL。      

Muscle tissue structural changes and texture development in sea bream, Sparus aurata L., during post-mortem storage

Sea bream, Sparus aurata L., specimens were studied in pre-rigor (3 h) and during the following post-mortem days: 1, 5, 10, 15 and 22. Muscle and textural parameters were evaluated on 6 specimens/stage. Structural results showed scarce fibre-to-fibre detachment on pre-rigor, which increased during the post-mortem degradation. Ultrastructural changes revealed rapid muscle degradation. In pre-rigor myofibrils were detached to both sarcolemma and endomysium. Intermyofibrillar spaces increased and some mitochondriae and sarcoplasmic reticulum were swollen. After 1 day, the sarcolemma appeared occasionally disrupted and the interfibrillar spaces increased. From 5 to 10 days, the I-band and Z line presented some alterations, although these were more severe at 15-22 days. Thus, in these two last stages, loss of I-band, Z line and actin filaments was observed, that coincides with the alteration of the hexagonal arrangement in these advanced stages. Also, the fragmentation of myofibrils increased from 5 to 10 days on. Sarcolemma and endomysium were gradually disrupted throughout the post-mortem stages with total loss at 22 days. Consequently, the interfibrillar spaces increased at last stages. Autophagic mechanisms increased from 5 days on, with an intense destruction of all the intracytoplasmic organelles. Textural parameters decreased from pre-rigor until 5-10 days, mainly associated to detachment of myofibers to sarcolemma-endomysium.     

A rapid and simple fluorometric method for quantifying isoeugenol in seawater and in plasma and white muscle from Australasian snapper (Pagrus auratus)

Isoeugenol residues in Australasian snapper (Pagrus auratus) white muscle, blood plasma and seawater were accurately and precisely quantified after extraction with acetonitrile using fluorometric detection (ex. 260 nm, em. 340 nm) without chromatographic separation. Isoeugenol residues in Australasian snapper (P. auratus) muscle tissue following 30 min exposure to 58.2 μmol L⁻¹ isoeugenol (ca. 20 ppm of the aquatic anaesthetic AQUI-S™) reached a maximum of 134.37 ± 8.13 μmol kg⁻¹ (±SEM; n = 6). Blood plasma isoeugenol concentrations following this harvesting regime were 253.2 ± 25.1 μmol L⁻¹. After 7 h recovery, fillet isoeugenol residues reduced to 7.89 ± 1.67 μmol kg⁻¹. Storage of fillets from fish harvested with AQUI-S™ at 3.87 ± 0.54 °C for 5 days resulted in a rate of isoeugenol decay in the fillets of 6.51 ± 1.19 μmol kg⁻¹ day⁻¹. The method reported can be used for measuring isoeugenol residues in food products or to further study the physiological and biological effects of isoeugenol in fish.     

Fish for human consumption: risk of contamination by mercury

Total mercury concentrations were measured in the muscle of different kinds of fish: megrim (Lepidorhombus boscii), common sole (Solea vulgaris), striped mullet (Mullus barbatus), anglerfish (Lophius piscatorius), and black-bellied angler (Lophius budegassa     

Breakdown of intramuscular connective tissue in cod (Gadus morhua L.) and spotted wolffish (Anarhichas minor O.) related to gaping

The purpose of this work was to compare the microstructure of muscle connective tissue in cod and wolffish and to study its degradation during ice-storage to determine which structural alterations are related to the gaping phenomenon. Gaping is very often found in fillets of codfish, but not in wolffish. The results showed that detachments between myofibres occurred prior to the myotomes to myocommata detachments, which occurred more rapidly and to a larger extent in cod than in wolffish. Changes at the ultrastructural level in myocommata proper were mainly related to gaps between collagen fibres and between collagen fibres and cells in the extracellular matrix (ECM). The mean collagen fibre diameter was smaller and the collagen network in myocommata proper was denser in wolffish than in cod. After 7 days of ice-storage the collagen fibres, particular in cod, appeared sparsely packed. The results implied that the increased gaping during ice-storage might be due to degradation of proteoglycans and glycoproteins, important for the spatial organization of the collagen fibres and in anchoring cells in the ECM to the collagen network.     

Effect of extracting time and temperature on yield of gelatin from different fish offal

The aim of the study was to determine the optimal conditions for preparing gelatin from different kinds of fish offal: heads and backbones of Baltic cod, skins of fresh and cold-smoked salmon, and skins of salted and marinated herrings. The yield of gelatin extraction at 45 °C was 71–75% for fresh salmon skins or cod backbones, and 86%, for smoked salmon skins. When heating marinated herring skins for 15 min or salted herring skins for 45 min, about 100% of collagen was converted to gelatin. For fish skins, 45 °C and 15–60 min extraction time, depending on the kind of skins, were established as optimal conditions for preparing gelatin. The yield of gelatin extraction from the cod heads did not exceed 70%, even when a three stages process was used. In the case of backbones, 100% of collagen in the form of gelatin was isolated using this procedure. SDS-PAGE analysis showed that gelatin from fish skins was much less degraded than gelatin from pigskins.     

Behaviour of connective tissue in fish surimi on fractionation by sieving

The surimis prepared from the three fish species, red barracuda Sphyraena pinguis, yellow sea bream Dentex tumifrons, and spotted shark Mustelus manazo, were fractionated by sieving through a 30-mesh stainless steel sieve. Chemical analyses revealed significant differences in the collagen content among the residual fraction on the sieve (fraction A), the passed fraction (fraction C), and the original surimi before sieving (fraction B): the fractions A and B showed values 10–20 and 5–10 times higher than those of the fraction C, respectively, for all the species examined. Histological observation indicated the richness of the thick connective tissues derived from myocommata in fractions A and B, while thick connective tissue was hardly observed in fraction C. These results suggested that the present fractionation method may have an effect of reducing the collagen content to about 10–20% of the original value, and that a large part of collagen in fish surimi exists in the relatively thick connective tissue, probably derived from myocommata.     

油菜湿害及耐湿性机理研究进展

湿害威胁中国的油菜生产。本文阐述了前人关于湿害对植物生长的危害机理,概括了湿害对油菜生长的影响、油菜耐湿性的遗传多样性、油菜耐湿性形成的生理生化和遗传机理的研究进展,指出今后应重点建立油菜耐湿分子育种技术,深入研究耐湿基因网络,发现和克隆耐湿相关基因,为提高油菜的耐湿性奠定基础。     

Properties of a protein-based film from round scad (Decapterus maruadsi) as affected by muscle types and washing

The effects of muscle types and washing on the properties of a protein-based film from round scad (Decapterus maruadsi) mince were investigated. Washing resulted in an increase in the protein content with a coincidental decrease in the fat content of mince, especially from whole muscle and dark muscle. Among all types of muscle (ordinary, dark and whole muscle), the ordinary muscle rendered the film with the highest tensile strength (TS) (p < 0.05). TS of films from washed mince was greater than that of films prepared from unwashed mince for the same type of muscle used (p < 0.05). Nevertheless, the water vapour permeability (WVP) of films from unwashed mince was higher than that of films prepared from washed mince (p < 0.05). Films from washed mince had higher solubility but lower protein solubility than those from unwashed mince (p < 0.05). Regardless of washing, films from ordinary muscle showed the highest L^∗-value (p < 0.05). However, films prepared from dark muscle were more yellowish than those prepared from other muscles, as evidenced by the greater b^∗-value. Films from round scad mince and washed mince had excellent barrier properties to UV light at the wavelength of 200–280 nm. Generally, films from round scad mince had a lower preventive effect on visible light transmission than had those from unwashed mince. Among films from all muscles, those prepared from dark muscle exhibited the highest barrier to visible light transmission (p < 0.05). Therefore, the properties of films from round scad meat were governed by muscle type as well as by washing.     

Raman spectroscopy a promising technique for quality assessment of meat and fish: A review

Raman spectroscopy data have been compared to different traditional methodologies such as protein solubility, apparent viscosity, water holding capacity, instrumental texture methods, dimethylamine content, peroxide values, and fatty acid composition commonly used to determine quality in fish and meat muscle treated under different conditions of handling, processing and storage through the changes of proteins, water and lipids of muscle food. It has been shown that Raman spectroscopy data are related to the results obtained with these traditional quality methods and could be used to evaluate muscle food quality. In addition, Raman spectroscopy provides structural information about the changes of proteins, water and lipids of muscle food that occur during the deterioration. Raman spectroscopy can also be used for determining muscle food identification. Besides, this spectroscopy technique has several advantages compared to traditional methods since it is a direct and non-invasive technique which requires small portions of sample.