国产中性蛋白酶水解贻贝初探

本文研究了采用国产１６６、３９４２中性蛋白酶，水解翡翠贻贝肉的条件和工艺。经测定，１６６中性蛋白酶在４０℃、加酶量在３％；３９４２中性蛋白酶在４５℃下、加酶量在３％时，酶解效果较好。在上述条件下酶解作用５小时，两种酶的酶解率均超过５０％。     

蛋白酶水解牛蛙排的工艺探讨

本文叙述了以生产冷冻牛蛙腿的下脚料牛蛙排作为原料，选用不同种类的蛋白酶进行水解比较试验，以挥发性盐基氮作为指标，认为选择木瓜蛋白酶较合适。同时对木瓜蛋白酶的用量，原料加水量，水妥时间及水解度进行了探讨，确定了木瓜蛋白酶水解牛蛙排较适宜的水解条件：加水量为原料的２倍，水解时间２小时，蛋白酶帮量为０．０９，水解度为５３．９％。     

酶法水解加工废弃鱼头的工艺探索

鱼头营养丰富 ,富含蛋白质、脂肪、氨基酸等物质。利用酶对加工中废弃鱼头进行水解 ,制得香味浓郁、红褐色的水解液 ,其中氨态氮含量为 6 4mg/mL。     

贻贝肉被膜冷冻试验

贻贝味道鲜美,营养丰富,但不耐冻,长时间冷藏就会发生干耗、褐变,解冻后汁液流失多,烹调时易破碎,口感发渣等。为了能较长时间保持冷冻品质量,我们在被膜剂研究的基础上,选出几种比较理想的被膜剂,对贻贝进行被膜工艺的研究及冻结、冷藏、解冻、烹     

梅童鱼内源蛋白酶自水解工艺的优化

为提高海捕低值鱼加工利用率,合理利用鱼糜及鱼糜制品加工中的副产物,充分利用鱼类自身内源酶,寻求低值鱼精深加工的低碳高效利用,以梅童鱼(Collichthys lucidus)为研究对象,利用鱼类自身的内源蛋白酶将鱼体内的蛋白质酶解,在自然p H条件下,观察了液料比、自溶温度、时间对梅童鱼蛋白水解的影响,以可溶性蛋白/总蛋白的值为响应值,采用响应面分析优化自溶条件。通过求解回归方程得到的最优自溶条件为:液料比3.4,温度53℃,时间267 min。经过验证,可溶性蛋白/总蛋白的值为18.35%,与回归方程的预测值18.55%相比,相对误差1.1%,说明模型能较好地预测自溶过程中可溶性蛋白/总蛋白的值。在此条件下,测得水解度为15.84%,过0.45μm微滤膜蛋白质量比为9.83%。研究表明,该水解工艺可为生产鱼露、活性肽、氨基酸等提供技术依据。     

正交试验优化天然虾青素的提取工艺研究

研究了负压空化法提取虾壳中虾青素的各项工艺条件对虾青素提取效果的影响,通过正交试验确定了负压空化法提取最佳工艺参数为提取溶剂是浓度80%的乙醇溶液,提取时间为35min,料液比为1：20,通气量为0.2m^3·h^-1。同时将负压空化法与常用破壁提取方法的提取效果和效率进行了比较,综合结果表明,负压空化法优越于其它方法,是一种能够适应工业生产的新型提取方法。     

Hns对紫贻贝和牡蛎的急性毒性试验

采用环境毒理学急性毒性试验分析方法,分别于24、48、72和96 h研究Hns对海洋污损生物紫贻贝和牡蛎的半数致死浓度、95％置信区间和安全浓度(CS).结果表明,Hns对紫贻贝的毒性比对牡蛎的毒性高,安全质量浓度为0.854 mg/L,几乎是Hns对牡蛎毒性的8倍.     

翡翠贻贝冷冻方便食品试验总结

翡翠贻贝(俗称青口)，是我国南方主要海产贝类之一。贻贝肉质鲜美，营养丰富，是宾馆、酒楼宴席和居家的美味佳肴。近年来，我省沿海贻贝养殖发展很快，台山市1993年贻贝养殖面积1059公顷，产量9050吨；1994年贻贝养殖面积达到1300公顷，预计产量可达11700吨。贻贝的收获期较集中(一般是4-5月，7-8月，11-12月)。贻贝上水后保鲜期较短，一般是1-2天。我们曾经把贻贝加冰运送并出售，也只能保存3天，     

翡翠贻贝与对虾混养试验

翡翠贻贝是暖水性贝类，属软体动物办鳃纲、贻贝科，广东俗称“清匙”、“清口”。个体一般重50—100克，肉质鲜美，营养丰富，其食用或药用价值较高。随着人们生活水乎的提高、消费观念的改变，翡翠贻贝在市场上倍受青睐，近年来，出现了迅速发展的好势头。1991年，我所海水养殖试验场进行了翡翠贻贝与对虾的混养试验，现将试验结果介绍如下。     

文蛤和波纹巴非蛤冷冻变性的比较研究

利用IMP热电偶测温系统及组织切片技术、食品化学特性的常用分析方法以及测定表征蛋白质变性的盐溶性蛋白溶解度和Ca2 ATPase活性,对文蛤和波纹巴非蛤在冷冻后的组织结构、食品化学特性、蛋白质变性的影响进行了比较研究。结果表明:冻结会使贝肉组织结构发生较大变化,水分流失,非蛋白氮显著增加,但冻结对贝肉蛋白质冷冻变性的影响不明显;在冻藏后贝肉蛋白质发生了较大变性。在相同冷冻条件下,文蛤在上述3方面受到的影响均比波纹巴非蛤受到的影响大,说明文蛤比波纹巴非蛤更容易发生冷冻变性。     

翡翠贻贝双酶水解法的建立

研究了双酶法水解技术水解翡翠贻贝并制作海鲜调味料。研究结果表明：（１）水产品快速自溶技术不能应用于翡翠贻贝贝肉蛋白的水解;（２）翡翠贻贝贝肉蛋白可以用外源酶对其水解;（３）枯草杆菌中性蛋白酶和胃蛋白酶都可以对贝肉蛋白水解;（４）利用正交试验分别确定了两种酶的最适水解条件并用双酶法水解新技术对贝肉蛋白水解;蛋白质水解率达到８２％;（５）试验中确定的酶的水解条件为枯草杆菌中性蛋白酶：ｐＨ７．５,温度４     

乌伦古湖白斑狗鱼摄食生态的初步研究

2007年4月至2008年9月对乌伦古湖153尾白斑狗鱼,进行食性研究.结果表明,白斑狗鱼的食物组成包括池沼公鱼、湖拟鲤、东方欧鳊、银鲫、贝加尔雅罗鱼、粘鲈、麦穗鱼、尖鳍鮈、北方花鳅、北方须鳅、中华绒鳌蟹、摇蚊幼虫、水生昆虫共12种饵料生物,主要以池沼公鱼(IRI=88.44%)、湖拟鲤(IRI=6.66%)和银鲫(IRI%=2.57%)为主.白斑狗鱼除繁殖期外,其他月份摄食率都很高,繁殖期过后5月中旬摄食率达到65%,8月份达到68%,冬季封冰下达到66.7%.白斑狗鱼平均饱满指数变化较大,其变化幅度在0.0016～0.2286之间.Shannon-Wiener多样性指数H' 5月份最小为0.5128,8月份最大为1.9863.Pielou均匀度指数J' 5月份最小为0.4668,8月份最大为0.7993.8月份白斑狗鱼食物Pielou均匀度指数J' 均高于5月份.     

Prediction of cannibalism in juvenile black rockfish,Sebastes schlegelii (Hilgendorf, 1880), based on morphometric characteristics and paired trials

To predict the occurrence of cannibalism in the culture of larval black rockfish, Sebastes schlegelii, we developed a regression model based on morphometric measurements. First, 156 black rockfish were measured to obtain a theoretical model, that is L_{T prey} = 0.624 L_{T cannibal} + 0.835. Then, 202 trials of paired fish, together with 31 pairs of cannibalistic fish, were used to revise this model, and the practical model was constructed: L_{T prey} = 0.522 L_T cannibal + 4.908 (R² = 0.99). According to this equation, the threshold of size ratio was deduced, that is 1.30–1.69, which could be used to grade black rockfish by size and remove potential cannibals.     

人工养殖鲟鱼鱼体质量百分组成

以俄罗斯鲟、史氏鲟、西伯利亚鲟、达氏鳇4个品种的19尾活体鱼为试验材料,按照鱼体质量>10 kg和<5 kg分组进行解剖,得出了13个解剖部位的质量分布情况。试验结果表明,鲟鱼的出肉率约50%,且史氏鲟最高,其他依次为西伯利亚鲟、俄罗斯鲟、达氏鳇。     

Comparative fishing trials for <Emphasis Type="Italic">Charybdis japonica</Emphasis> using collapsible box-shaped and dome-shaped pots

ABSTRACT:   Comparative fishing trials were undertaken with two commercial collapsible pots for the crab Charybdis japonica . One pot was box-shaped with two slit entrances at the ends, while the other was dome-shaped with two open funnel entrances. Pots were placed at the bottom of a pond that is connected to Kagoshima Bay. Fishing trials were carried out using a 1-day soaking time; the bait used was mackerel. The box-shaped pot had higher catches of crabs and non-target organisms, but the number of large crabs (carapace width >8 cm) was almost half as many as that caught with the dome-shaped pot. The catch of non-target species was also greatly reduced in the dome-shaped pot, and fish caught were mostly enmeshed in the netting. The reduction in catches of small crabs and non-target organisms was due to the nature of the dome-shaped pot's larger mesh size and open entrances, which allowed for escape. The dome-shaped pot seemed more efficient for harvesting commercial size crabs, while the box-shaped pot seemed better for removing all crab sizes.     

黄渤海鲻生长的初步研究

对采自黄渤海沿岩的鲻样品进行了生物学测定，研究了鲻的两性生长，相对增长率，生长指标，生长参数，生长速度和加速度。     

Nutritive value of squid and hydrolyzed protein supplement in shrimp feed

Though some protein sources like squid and protein hydrolysates are assumed as growth enhancers for shrimp, little is known about the biochemical basis of this phenomenon. Low, heat-dried squid (Dosidicus gigas) (SQ) and two commercial protein hydrolysates from fish (FH) and krill (Euphasia sp.) (KH) were assayed in feeding trials with Penaeus vannamei. Feeds were prepared with the tested proteins at 3%, 9%, and 15% of the total crude protein. A total of nine experimental feeds plus a commercial one as control (C32) were tried. Additionally, digestibility in vivo and in vitro was evaluated. Survival was not different among groups. Weight gain of shrimp and total and specific proteolytic activity for trypsin and chymotrypsin were affected by type and quantity of supplemented protein. In vivo and in vitro digestibilities were also influenced by the source and quantity of the protein supplement. Shrimp fed feed with FH at 3% protein supplementation grew more than those fed with higher supplementations. Groups fed SQ had similar results as those fed FH, and gained more weight when fed the lowest SQ quantity. SDS-PAGE showed a large concentration of small peptides in SQ, which may explain results similar to FH. KH enhanced shrimp growth at all supplementations and had a lower degree of hydrolysis (DH) than FH. SQ also demonstrated good growth performance, but better at the lower supplementation, probably because of the presence of small peptides and possibly free amino acids from protein hydrolyzed by endogenous enzymes in the squid mantle. We conclude that hydrolyzed protein is a good supplement for shrimp feeds, but it must meet specific requirements for adequate assimilation.     

Effects of Manipulation of Proteases on Myofibril Protein Degradation of Tilapia Muscle in vitro and in vivo

This study investigated the role of three proteases in myofibril degradation. Tilapia muscle was soaked in MDL-28170, E-64, and AC-DEVD-CHO, specific inhibitors of calpain, cathepsin, and caspase, respectively, for 14 days to determine the in vivo degradation of myofibril. Desmin and troponin T were significantly inhibited after treatment with inhibitors compared to the control (p < .05). For in vitro analyses, myofibril was incubated with recombinant active μ-calpain, cathepsin B, and caspase-3. Desmin was significantly reduced when incubated with recombinant proteases (p < .05). However, troponin T showed significant degradation only in the μ-calpain and cathepsin B treatment groups (p < .05). Our results reveal μ-calpain and cathespin B have similar degradation patterns, while caspase-3 has partly similar degradation for myofibril in vivo and in vitro. This suggests that μ-calpain and cathespin B are the main proteases responsible for post-mortem myofibril degradation, while caspase-3 is minor.     

铁肽螯合物不同组分对缺铁性贫血大鼠贫血改善的研究

为有效利用带鱼加工下脚料类资源,本研究采用凝胶层析法对制备所得的带鱼加工下脚料酶解亚铁螯合物进行了分离分级,初步确定了不同分离组分的分子量及回收率,采用氨基酸自动分析仪确定了不同分子量组分的氨基酸成分与含量,并进行了氨基酸评分;而后通过缺铁性贫血大鼠模型研究了不同分子量组分对大鼠贫血的改善效果。结果显示,带鱼下脚料经酶解、亚铁螯合修饰和层析分离后得到4类分离产物,分子量分别约为35 400,8 720,465和小于200 u;除组分Ⅱ含有8种必需氨基酸外,其他组分均属于不完全蛋白质;理想氨基酸模式评价结果表明4类螯合物氨基酸价分别达到理想氨基酸模式的85.31%、88.22%、101.32%和105.83%,仍然属于质量较高的蛋白质;不同分子量螯合物中铁含量存在显著差异,其中以组分Ⅰ含量最高(5.23%),组分Ⅱ含量最低(3.34%),组分Ⅲ和组分IV铁含量接近(4.22%和4.58%);不同分子量螯合物对大鼠体质量、Hb、血清铁、血清铁结合力、肝脏M DA和SOD影响不同,其中组分Ⅱ对缺铁性贫血大鼠贫血改善效果最好,且效果优于Fe SO4,组分Ⅰ在螯合物中效果最差,但仍有一定改善效果。