利用鲐鱼下脚料加工浓缩鱼蛋白

利用鲐鱼内脏蛋白酶来分解鲐鱼头尾下脚料生产第二代饵料—浓缩鱼蛋白,通过多次小样试验得到了该工艺中几个重要的工艺参数,即酶解过程中内脏投入比例为15％到25％;pH控制在8.5～9.0;最适反应温度为48～50℃。由试验结果制定了浓缩鱼蛋白生产的整个工艺。按照此工艺又进行了批量试验,由此而得到酶解过程酸、碱的单耗;浓缩鱼蛋白及其副产品的得率,并将所得产品进行成份测定,其质量已接近美国AHS技术产品,最后还将该产品与鱼粉比较,其营养价值明显优于鱼粉。     

英国利用鱼下脚制成液态鱼蛋白

英国利用鱼的下脚加工成液态鱼蛋白，作家畜的饲料，取得了进展。     

用液态鱼蛋白作动物饲料

<正> 液态鱼蛋白是一种液体制品,是在整条鱼或鱼的某部分里加上酸,利用鱼本身所存在的酶使之液化。成品里可能确鱼油,也可能不含鱼油,这要看原料本身是否含油。液态鱼蛋白一般用作动物饲料。制备液态鱼蛋白作动物饲料的想法早在二十年代的芬兰就已开始,有关资料很少,仅 Petersen(1953)对酸保藏鱼和鱼的下脚作了评议;McBride 等(1961)对鲱鱼的液化作了全面的调查。苏联于1958年开始     

水解鱼蛋白营养组成及评价

利用分析化学方法对水解鱼蛋白、经超滤的水解鱼蛋白、鱼粉、酪蛋白、豆粕的营养成分进行了分析、评价.结果表明,经超滤的水解鱼蛋白的蛋白质含量显著高于未经超滤的水解鱼蛋白的蛋白质含量(P<0.05),超滤减少了水解鱼蛋白的脂肪含量,增加了水解鱼蛋白的灰分含量;水解鱼蛋白、经超滤的水解鱼蛋白、鱼粉、酪蛋白、豆粕氨基酸总量依次为62.24、62.34、50.78、74.33、37.36mg/100 mg,必需氨基酸占总氨基酸的比值(EAA/TAA)依次为47.41%、49.47%、49.90%、48.41%、49.25%;水解鱼蛋白含有丰富的牛磺酸;水解鱼蛋白和鱼粉含有丰富的碘和硒;水解鱼蛋白和鱼粉中维生素B2和B5含量较为丰富.水解鱼蛋白具有平衡的氨基酸组成,较高水平的牛磺酸和维生素B2、B5、丰富的微量元素碘和硒,是优质的蛋白原料.     

浓缩鱼蛋白的研制

本文对影响浓缩鱼蛋白产品质量的因素进行了研究。通过不同工艺参数，生制与熟制、板框压滤和离心脱脂等方面分别进行了试验，经综合分析，试验结果表明工艺参数确定为：脱脂溶剂浓度在８５％－９５％之间；脱脂温度：第一次脱脂为室温第二、三次脱脂温度为７５℃。     

鱼蛋白的综合利用途径1.鱼粉

就有关低值鱼及水产加工废弃物中鱼蛋白的开发研究及应用情况做系列介绍,本文就低值鱼蛋白主要利用形式即鱼粉进行了分析和讨论。     

巴西研发出廉价液体鱼蛋白虾饲料

<正>巴西联邦农业大学的研究人员研发出了采用液体鱼蛋白替代鱼粉的养虾新饲料。液体鱼蛋白源自通常被丢弃的鱼下脚料,其成本只有鱼粉的十分之一,将为养虾者带来可观的经济效益。该研究项目是巴西科技部资助的虾类养殖国家计划的一部分,于2012年启动并在2014年3月结题,成果包括研究数据和科研论文。使用鱼粉的虾饲料使得虾农不得不依赖于捕捞渔业。而液体鱼蛋白只需最少量的设施和装备采用通常被丢弃的鱼下脚料制作而成,因此是虾饲料蛋白质来源的一个很好的选项。     

浓缩鱼蛋白及其应用

浓缩鱼蛋白对于解决当前世界上粮食短缺、营养不良等现象极为重要。开展鱼类浓缩蛋白的研究和制造已引起营养学家以及水产界的普遍注意。     

液化鱼蛋白和酸性稳定的鲜贮饲料的营养价值

用传统方法制作的鲜贮鱼饲料(pH4.0)含有多种活性酶体系,这些活性酶体系不仅把鱼蛋白质水解成短链的肽和游离的氨基酸,而且还使游离的氨基酸分解成氨和其他新陈代谢的产物。酸性稳定的鲜贮鱼饲料(pH2.0)仅含有由内源胃蛋白酶释放的多肽和微量的游离氨基酸及分解产物。液化鱼含有稳定的中等链长的多肽。液化鱼的制作过程是这样的:在温度为60℃和生理pH(6.2—6.6)下,让鱼体自溶分解不足一小时,然后经过巴氏法杀菌,再使之酸化到pH4.0。上述制作过程提供了一种适应于各种水生动物和陆生动物对营养不同需要量的调节自溶鱼蛋白中肽和游离氨基酸含量的办法。     

鱼肠道弧菌外膜蛋白抗原性分析

采用十二烷基肌氨酸钠法和苯甲基磺酰氟法提取鱼肠道弧菌外膜蛋白.SDS-PAGE图谱显示,PMSF提取的鱼肠道弧菌有19条带,Sarkosyl法提取的鱼肠道弧菌有14条带,其中111、105、87、78、61、58、53、48、45、40、36、33、32、31 kD蛋白带为2种方法共同条带,101、55、42、27、25 kD为PMSF法特有条带.此外,以制备的兔抗鱼肠道弧菌全菌血清为第一抗体,应用Western-blotting技术分析了鱼肠道弧菌外膜蛋白的抗原性,结果显示分子量为106、87、61、58、55、42、36、32 kD的8条蛋白带发生了免疫反应.     

Growth Rate of Pacu,Piaractus mesopotamicus,Fingerlings Fed Diets Containing Co-Dried Fish Silage as Replacement of Fish Meal

Abstract

Fish meal has been the most common animal protein source used to feed fish, even though it is fairly expensive and seasonally available. The objective of this work was to investigate co-dried fish silage as an alternative animal protein source for diets of pacu, Piaractus mesopotamicus.The diets did not differ significantly (P >0.05) with respect to average weight gain, ration consumption, apparent feed conversion, protein efficiency and specific growth rates. However, apparent protein digestibility and protein productive values were significantly different (P <0.01). Diets containing fish silage, co-dried with agricultural by-products (soybean meal or broken rice), showed better results than the control diet, which contained fish meal as the only animal protein source. The results showed that alternative ingredients can be used effectively to replace fish meal in pacu diets. Co-dried silages are economically and environmentally advantageous, since they use residues generated in the farm.     

The Effects of Fermentation Process with Acid and Lactic Acid Bacteria Strains on the Biogenic Amine Formation of Wet and Spray-Dried Fish Silages of Discards

The impacts of fermentation process with acid and lactic acid bacteria strains (Lactobacillus plantarum, Lactobacillus brevis, Pediococcus acidilactici, Enterococcus gallinarum, and Streptococcus spp.) on the biogenic amine formation of wet and spray-dried fish silage obtained from whole gibel carp (Carassius gibelio, freshwater discard), whole ponyfish (Equulites klunzingeri, seawater discard), and processing by-products of seabass (Dicentrarchus labrax) were investigated. The results showed that among biogenic amines, cadaverine, putrescine, spermidine, spermine, serotonin, dopamine, and agmatine were predominant in all groups. Significant differences (p < 0.05) in biogenic amine concentrations of wet and spray-dried fish silage were observed. Raw fish and wet silages contained histamine level lower than the allowable limit of 50mg/kg, indicating the use of raw fish material with low microbial counts. In addition, no histamine was detected in spray-dried fish silage, except for seabass by-products with a trace quantity of histamine (<0.04mg/100g). The starter culture used for silage preparation did not effectively retard formation of biogenic amines compared to acid silage. It can be concluded that there is potential use of fermented fish silage as a protein source and possibly as a probiotic ingredient for animal feed in both wet and dry form.     

Apparent digestibility coefficient of protein and amino acids of acid, biological and enzymatic silage for Nile tilapia (Oreochromis niloticus)

Using the fish silage to partially replace proteic feedstuff in aquafeeds is an alternative to mitigate sanitary and environmental problems caused by the lack of adequate destination for fisheries residues. It would also lower feed costs, consequently improving fish culture profitability. However, using fish silages in aquafeeds depends on determination of its apparent digestibility coefficients (ADC). This work aimed to determining the ADC of crude protein and amino acids of acid silage (AS), biological silage (BS) and enzymatic silage (ES) for juvenile Nile tilapia (94.5 ± 12.7 g). The ADC_CP was: 92.0%, 89.1% and 93.7% for AS, BS and SE respectively. The average ADC of amino acids was: 91.8%, 90.8% and 94.6% for AS, BS and ES respectively. Results encourage the use of AS, BS and ES to partially replace protein sources in balanced diets for neotropical fish.     

Fish Processing By-Products as a Potential Source of Gelatin: A Review

ABSTRACT

The current practice of fish processing generates large amounts of by-products, which can account for up to three-quarters of the total fish weight. Despite the presence of several valuable components in the fish processing discards, the latter are usually dumped into landfills or at sea, having potentially harmful environmental effects or end up as low commercial value products (e.g., white fish meal). Still, fish processing by-products can be considered as an alternative raw material for the preparation of high-protein ingredients, especially for the production of food grade gelatin due to the presence of large amounts of collagen in fish skins, scales, and bones. Although fish gelatin is an alternative to the commercially available mammalian gelatins, its production on a large commercial scale has been hampered, mainly, due to the inferior quality characteristics compared to its mammalian counterparts. This review article summarizes and highlights the potential utilization of by-products generated during fish processing for gelatin extraction. Furthermore, several technical challenges and directions of ongoing research are discussed.     

Effects on digestibility and growth of juvenile cobia (Rachycentron canadum) fed fish or crab silage protein

The study was conducted in Cam Ranh, Vietnam, in 1000‐L tanks supplied with recirculated and biofiltered saltwater (33‰ and 28.4 °C) to evaluate the potential use of lizard fish (Saurida undosquamis) or blue crab (Portunus pelagicus) acid silage protein for juvenile cobia (23–25 g). Six isoenergetic test moist diets (4915–5125 kcal kg^?1), using either raw fish diet, fish silage diet (FSD), raw crab diet, crab silage diet (CSD), mixed raw fish/raw crab diet or mixed fish/crab silage diet (MSD), as part of the protein sources in the steam‐cooked diets, were fed to satiety to triplicate groups of 20 fish each for a 6‐week growth trial. Y₂O₃ was added as an inert indicator to determine the apparent digestibility coefficients (ADC) for macro nutrients and gross energy. Weight gain (185–286%) and specific daily growth rate (2.5–3.2% per day) were significantly higher in cobia fed the raw‐based diets and FSD than in fish fed CSD and MSD (34–90 and 0.7–1.5% per day). Feed conversion ratios (FCR) were significantly higher in the groups fed CSD and MSD diets (2.1–6.5) than the groups fed the other diets (1.0–1.2), resulting in significantly lower protein productive values (0.1–0.2) in the groups fed CSD and MSD than in the other groups (0.3–0.4). The FCR results were confirmed by significantly lower ADC values in fish fed CSD and MSD than those in fish fed the other diets. We thus conclude that the present raw‐based diets were better utilized by juvenile cobia than silage‐based diets, particularly the diet made from crab silage.     

环境DNA技术及在鱼类监测中的应用

随着人类活动的影响,鱼类资源正在急剧下降,开展鱼类监测对于鱼类多样性的保护具有非常重要的意义。传统的鱼类监测方法因具有破坏性、调查者也要专业形态学知识、调查工作量大等弊端,故亟需一种新的技术方法进行辅助补充。环境DNA （eDNA）技术的发展使得鱼类调查更加的省时省力、节约成本、无损伤,目前在鱼类的监测中广泛使用,然而eDNA技术也存在着一定的缺陷所以不能完全取代传统方法。eDNA技术包含了样品的采集及处理、eDNA提取、eDNA扩增、测序和生物信息学分析几个主要步骤,在整个流程中每一个步骤都非常必要,对单个步骤又有不同的实验方案,选择不同对鱼类eDNA的检测效率也会产生重要的影响。目前国外对于eDNA技术应用于鱼类监测所研究的问题较为丰富而全面,如生物多样性监测、入侵物种检测、濒危物种检测和生物量的估算等,虽然国内的起步不晚,但国内对此研究方向较为单一,需要进一步重视。     

海水鱼的保活运输

常见的水产动物保活运输有增氧法、麻醉法和低温法。而冰温无水保活运输具有运载量大、无污染、质量高等优点，是海水鱼保活运输的发展方向。     

Chemical and Organoleptic Comparison of Fish Sauce Made from Cold Water Species and Typical Thai Fish Sauce

ABSTRACT

Organoleptic and chemical properties of fish sauce made experimentally from the four cold water fish species–Arctic capelin, Atlantic herring, Atlantic cod and blue whiting–were compared with three first grade commercial fish sauces made from tropical anchovies. Although the flavor of the fish sauces made from cold water species were judged as inferior to the flavor of the tropical fish sauces, the blue whiting and Atlantic herring sauces obtained fair ranking. Chemical analyses revealed that sugar had been added in all the three commercial sauces. Although sugar is added during blending just before bottling, flavor enhancing chemical reactions, between amino groups and reducing sugars, probably occur during storage of the final product. Accordingly, this procedure should be adapted also in preparation of fish sauce from cold water species.     

湑水河流域鱼类资源现状

2009年9月和2010年5月在湑水河流域对鱼类资源进行了调查,共捕获鱼类4目、10科、29种;湑水河上游太白段以山区溪流冷水型鱼类为主,种类较少;下游城固段海拔低,鱼类种类相对上游河段丰富.不同河段在不同季节的鱼类组成和质量密度有显著差异.与相邻山区的河流相比,湑水河鱼类资源较为丰富,但目前外部因素已经开始影响鱼类的生存与繁衍,河流污染和其他人为干扰可能对该流域鱼类造成不可逆转的生态影响.