生物保鲜对牡蛎冷藏保鲜效果的研究

对牡蛎采用复合生物保鲜剂处理和涂膜处理,在冷藏条件下(0～2℃)进行保鲜贮藏试验,探讨其在此过程中硫代巴比妥酸、游离脂肪酸、总挥发性盐基氮、Ca2+-ATPase等生化指标的变化。试验结果表明,冷藏条件下使用复合生物保鲜剂和涂膜处理,牡蛎的硫代巴比妥酸、游离脂肪酸、总挥发性盐基氮、Ca2+-ATPase等值明显优于对照组。据此可知,生物保鲜、涂膜保鲜在牡蛎冷藏保鲜过程中能有效地减缓脂肪氧化和蛋白质降解,延缓腐败变质。     

壳聚糖复合生物保鲜剂对池沼公鱼保鲜品质的影响

池沼公鱼作为长白山区冷水鱼的一种,属于小型经济鱼类,能整体食用,加工方便,营养丰富,味道鲜美,含有多种人体必需氨基酸,经济价值高,是一种很有发展前途的养殖鱼类. 生物保鲜剂是从植物、动物或微生物的代谢产物中提取的物质.随着人们对食品安全越来越重视,以壳聚糖、溶菌酶、茶多酚等一些天然无毒的生物保鲜剂为原料进行的保鲜处理技术受到人们的普遍关注,这些生物保鲜剂能抑制细菌生长,使水产品保持良好的感官品质. 本文通过对池沼公鱼的感官性状、pH值、TVB-N值和汁液流失量等指标的检测来比较不同配比的复合生物保鲜剂对池沼公鱼在冷藏期间(4±2℃)保鲜品质的影响,为研究延长冷藏池沼公鱼货架期的保鲜工艺提供技术基础.     

新型灯光围网渔船及其制冷技术

通过现场调研,介绍了一种新型的大型灯光围网渔船的设计开发.该型渔船采用先进的作业方式,保鲜工艺采用冷海水保鲜→冻结→冷藏,针对性强.渔船的航区大航程长,实际使用的效益良好.对开发利用外海中上层鱼类资源十分有利.对渔船深入分析发现,其制冷系统的自动控制、设备配置及制冷剂等方面,存在着较大的优化与节能潜力.     

谈谈我国水产品加工问题

近几年来，因海洋资源衰竭，而使经济鱼类捕获量．增加较慢。相反，市场供求量却迅速增长。为此，水产品加工的实际范畴就相当广泛，增加了不少新的内容。包括水产品保鲜(化学方法保鲜，降温冷藏保鲜)，各种水产品加工，特别是低值鱼类的加工，虾蟹类加工，藻贝类的加工，和水产品综合利用等。从我国沿海情况来看，     

保鲜处理对冷鲜鲟鱼肉特征性风味成分的影响

为明晰保鲜处理对冷鲜鲟鱼肉冷藏期间的特征性风味物质的影响。本实验利用固相微萃取—气相色谱—质谱联用(SPME-GC-MS)结合电子鼻和电子舌技术,对经微酸性氧化电解水和ε-聚赖氨酸两步法保鲜处理的冷鲜鲟鱼肉在冷藏期间的挥发性成分和滋味成分进行分析。电子鼻能够对挥发性成分从整体上进行分析,贮藏后期保鲜处理组和对照组的鲟鱼肉挥发性气味的数据集无重叠区域,差异明显。利用SPME-GC-MS定性鉴定出46种挥发性物质,主要包括醛类、酮类、烃类和醇类等物质,其中己醛、庚醛、苯甲醛、辛醛、壬醛、癸醛和2,5-辛二酮、苯乙酮、3,5-辛二烯-2-酮为保鲜处理组的主要挥发性物质,保鲜处理延缓了冷鲜鲟鱼肉腥味的产生以及鱼肉香味的下降。电子舌检测冷藏过程中鲟鱼肉的滋味物质时发现,保鲜处理组苦味、涩味、咸味均低于对照组,两组样品贮藏6 d后,在苦味、涩味、咸味、鲜味方面均呈显著差异。保鲜处理起到了减缓冷藏期间冷鲜鲟鱼肉风味物质下降的作用,为保鲜处理在冷鲜鲟鱼肉中的应用提供了一定的理论基础。     

CMC在缢蛏涂覆保鲜上的应用研究

采用羧甲基纤维素钠（CMC）作为缢蛏（Sinonovacula constricta）保鲜涂覆胶,在5℃下保藏7 d,以缢蛏的活泼度、成活率、水分蒸发量及挂胶量等为指标对其保鲜效果进行评价。试验结果表明,采用CMC保鲜胶涂覆的缢蛏,5℃下7 d的成活率为100%,而对照组的成活率为60%,涂膜处理能降低水分蒸发速度,保鲜效果显著。     

水产品的冷藏保鲜技术

水产品的保鲜方法主要有低温保鲜、高压保鲜、辐照保鲜、气调保鲜、生物保鲜等几大类,其中以低温保鲜法应用得最为广泛,研究得最为深入。根据目的和温度的不同,低温保鲜法又可分为冷藏保鲜和冷冻保鲜。目前,水产品的冷藏保鲜技术主要包括：冰藏保鲜技术、冷海水保鲜技术、冰温保鲜技术和微冻保鲜技术等几种。     

竹叶抗氧化物浸泡-乳清分离蛋白涂膜对冷藏富硒虹鳟蛋白质理化性质的影响

为从蛋白质水平解释竹叶抗氧化物浸泡-乳清分离蛋白涂膜对富硒虹鳟的保鲜机理,实验将鲜活富硒虹鳟去除头、内脏和表皮,切块后浸泡在1.0%的竹叶抗氧化物（AOB）溶液中（去离子水作为对照）,再进行乳清分离蛋白（WPI）溶液涂膜,25℃下鼓风吹干表面水分后置于4℃冰箱中贮藏1、4、7、10和13 d。测定鱼肉中肌原纤维蛋白和TCA-可溶性肽的含量、蛋白质的分子内价键,以及肌原纤维蛋白的总巯基含量、表面疏水性和二级结构,分析涂膜对冷藏富硒虹鳟蛋白质理化性质的影响。结果显示,冷藏期间,WPI组的肌原纤维蛋白含量和二级结构中β-折叠的含量显著高于对照组。冷藏1～7 d,WPI组的TCA-可溶性肽和二硫键含量以及表面疏水性指数（H₀）显著低于对照组,总巯基含量呈相反趋势,但随着冷藏时间的延长这些差异逐渐减弱。冷藏13 d时,WPI组与对照组无显著差异。3个实验组中,1.0%AOB+WPI组的肌原纤维蛋白、总巯基、氢键、二级结构中α-螺旋和β-折叠的含量在冷藏期间最高,H₀、TCA-可溶性肽、二硫键和二级结构中β-转角含量最低。WPI在鱼块表面形成一层薄膜,可...     

新书介绍

<正> 鱼制品工艺1980年,出版,共317页现代鱼制品工艺,涉及生物、化学、生化、微生物学、热工、机械等学科。鱼品加工技术也随之革新、发展。该书共十六章,主要介绍原料鱼、鱼类加工准备、鱼类冷藏保鲜及加工、盐及醋渍鲜鱼、鱼子罐头、鱼品干制、鱼品熏制、鱼品罐头、鱼糜制品、饲料加工品、海洋动物     

生物技术在水产品保鲜应用的研究进展

水产品因其蛋白质和水分含量较高、脂肪多呈液态,在运输和贮藏过程中极易发生腐败变质。生物技术作为新兴技术已应用于众多领域,但在水产品保鲜领域尚处于起步阶段。本文概述了酶制剂、可食涂膜、抗菌涂膜对水产品保鲜的研究,期望对水产品生物保鲜技术的进一步研究提供理论依据。     

壳聚糖在对虾保鲜中作用的初步研究

本试验采用壳聚糖为主要成分与常用的防腐剂和护色剂进行保鲜性能对比实验,以及在一定温条件下实验对虾类的防腐败保鲜效果,并且以感官指标、TVB-N值、pH值、细菌总数等作为鲜度指标定期取样测定。实验结果表明,壳聚糖涂膜保鲜剂和蜂胶保鲜剂用于对虾的保鲜效果良好,可以抑制细菌总数的增长,维持较低的TVB-N值,改善对虾的感官质量,延长对虾的贮藏期。     

鱼类生殖细胞移植技术的发展及应用前景

鱼类生殖细胞移植技术是通过诱导不同物种之间生殖系嵌合体来实现。原始生殖细胞和精原细胞(或卵原细胞)是诱导生殖细胞系嵌合体的关键材料。在过去的十多年中,通过采用不同的供体生殖细胞和不同发育阶段(囊胚期胚胎、初孵仔鱼和成鱼)的鱼为受体,开发出多种鱼类生殖细胞移植技术。这些成果的取得,为生殖细胞移植技术应用于诸多水产养殖新兴领域打下了坚实基础。该技术可以应用于:(1)生殖细胞生物学和转基因鱼等基础研究;(2)遗传资源和濒危鱼种的保护;(3)鱼类性别选择育种;(4)有效提高放流鱼苗的遗传多样性。     

淡水鱼产品保鲜技术研究现状

淡水鱼产品中不饱和脂肪酸含量较高,比畜肉和禽肉更容易被氧化,且鱼体细菌繁多,容易引起鱼肉蛋白的腐烂变质,因此淡水鱼产品的防腐保鲜一直是食品行业内的热点研究课题。本文主要介绍目前国内外普遍采用的淡水鱼产品保鲜技术,主要包括低温保鲜技术、包装保鲜技术、辐射杀菌保鲜技术、涂膜保鲜技术以及化学方法保鲜技术。     

快速制备脂肪酸甲酯用于气相色谱分析

在不需从原料中提取脂质,而直接将磨碎原料中的脂质皂化、甲酯化后,进行气相色谱的脂肪酸分析测定。这种方法与通常采用的先提脂质再行甲酯化的方法进行了比较,结果表明,分析测定的数据与普通法极为一致,其优点是快速、操作方便、节省药品;即使样品很少,用普通法不易提取脂质时,此法也能顺利地完成分析工作。     

A simple, rapid method for gizzerosine analysis in fish meal by paper electrophoresis

We established a simple, rapid method for gizzerosine analysis in fish meal. Gizzerosine was extracted from fish meal with 0.1?N HCl solution. Samples and standard gizzerosine solutions were absorbed onto a paper disc, which was then set on electrophoresis paper for 18?min, and the paper was dried. Gizzerosine was visualized with Pauly??s reagent, and the intensity of the colored spots was digitized and calculated by image processing method software. We achieved successful separation of gizzerosine from other Pauly??s reagent-positive components in fish meal extracts. The linearity of gizzerosine estimation using this method was within the range 30?C1000?ng (R ²?=?0.99). Gizzerosine was satisfactorily detected and completely separated from histamine and other Pauly??s reagent-positive compounds. This method does not require expensive instruments or tedious pretreatment to eliminate interfering compounds, such as histamine or histidine. It also uses less reagent compared with high-performance liquid chromatography. Moreover, it is a simple, rapid, sensitive, and reproducible method. It is suitable for monitoring gizzerosine in fish meal products that contain as little as 10?ppm gizzerosine.     

鱼类配子和胚胎冷冻保存研究进展及前景展望

种质资源是水产养殖生产、优良品种培育及水产养殖业可持续发展的重要物质基础。我国是一个水生生物种质资源较为丰富的国家 ,丰富多样的水生生物种质资源和遗传多样性对于我国水产养殖业的快速发展起到了非常重要的作用。然而 ,由于渔业资源的过度捕捞、无序利用及人工放流等 ,造成了某些鱼类资源的衰退和濒临灭绝 ,如不及时采取保护措施 ,若干年后 ,在自然界中将难以找到上述鱼类原种、良种的遗传资源 ;由于忽视鱼类种质保护及品种选育的工作 ,养殖鱼类近亲交配越来越严重 ,造成种质退化 ,遗传多样性减少 ,生长速度减缓 ,品质下降 ,对病害…     

History,current status and prospects of sturgeon aquaculture in Russia

Since natural sturgeon populations have drastically declined, aquaculture of these valuable fish is important to meet the ever‐increasing demand for meat and caviar, thereby reducing the pressure on natural sturgeon resources. There are two directions in sturgeon aquaculture: controlled propagation for release and commercial farming. The controlled propagation supports the conservation of natural fish populations, while the commercial cultivation of sturgeons supplies the needs of the consumer market with the delicacy production of caviar (mainly). This review deals with the current status of the controlled propagation and stocking in the Volga‐Caspian basin and the commercial farming of sturgeons in Russia. The article also investigates the management of farmed broodstocks of sturgeons, which are used for obtaining seedlings and caviar. It is for sure that the active and continuous development of the two directions of sturgeon aquaculture will allow preserving these unique ancient fish on our planet until natural populations can be re‐established by self‐sustaining populations.     

Lipid-based transfection as a method for gene delivery in zebrafish (Danio rerio) embryos

A major challenge to the widespread production of transgenic, knockout and knockdown zebrafish has been the absence of a simple and effective procedure for introducing macromolecules into the fertilized egg. None of the existing techniques for gene transfer in fish embryos has proven to be a major advance over cytoplasm microinjection, which is a technically demanding and time‐consuming procedure. This report addresses this need, considering that the development of protocols for lipid‐based transfection with fish embryos would considerably simplify gene transfer in this complex biological model. In this study, lipid‐based transfection with two different reporter vectors was carried out in zebrafish embryos at different developmental stages. The parameters tested included different plasmid/transfection reagent ratios as well as the influence of an added transfection enhancer reagent. When embryos were transfected in the blastula stage with a pEGFP‐N1 vector, more than 35% successfully incorporated the plasmid and expressed the fluorescent protein 24 h after transfection. The transfection enhancer did not show any significant effect in our experiments. This work presents an approach to implement this technique as a faster, cheaper and more practical alternative than microinjection.     

Larval and early juvenile fish dynamics in main channel and backwater lake habitats of the Illinois River ecosystem

The spatial and temporal complexity of large river ecosystems likely promotes biological diversity within riverine larval fish assemblages. However, the focus of most previous riverine studies of larval fish distribution has tended to concentrate mainly on backwater habitats. There has been less focus on the value of the main channel for larval fishes. We sampled two habitats types (three main channel sites and three backwater lakes) along 20 km of the Illinois River ecosystem during 2 years to compare the larval fish distribution along both spatial and environmental gradients between these habitats. Across the 2 years of this study, we found similar trends in the spatial and temporal distribution of larval fish, although there were some differences in densities between years. The relative abundance and size of many of the different fish taxa varied among habitats. Centrarchids, clupeids, poeciliids, cyprinids (excluding common carp) and atherinids were more abundant within backwater lake habitat. In contrast, common carp (Cyprinus carpio), sciaenids, moronids and catostomids were more abundant in main channel habitats. Furthermore, sciaenid and clupeid larvae captured in the backwater lake habitat were larger as the season progressed than those captured in the main channel. Our study suggests that larval fish show habitat specialisation, similar to adults, indicating that both the backwater lakes and the main channel are both important for larval fish and preserving the diversity of the fish assemblages in large floodplain rivers.     

River modification reduces climate resilience of brown trout (Salmo trutta) populations in Ireland

This study investigated interactions between eco‐hydromorphological state, riparian vegetation cover, water temperature and fish community composition in lowland rivers in Ireland. Physical habitat modification of study sites corresponded with degraded eco‐hydromorphological state (degree of ecological and physical modification) and reduced thermal buffering capacity (greater temperature fluctuation and increased frequency of extreme temperature events). This impact was reflected in the fish community, with a shift from a brown trout‐dominated (Salmo trutta L.) fish assemblage to predominance of the more thermally plastic minnow, Phoxinus phoxinus (L.), and stone loach, Barbatula barbatula (L.). Eco‐hydromorphological state may be a central factor affecting the ability of temperate rivers to resist temperature change in a warming climate and to maintain suitable conditions for salmonids and other cold‐water biota. Strategies aimed at climate change proofing of temperate rivers should focus on preserving or re‐establishing the eco‐hydromorphological processes that create habitat complexity and buffer stream temperature.