鲟鱼皮软包装冷冻调理食品加工工艺

试验以鲟鱼皮为原料,通过试验确定了鲟鱼皮软包装冷冻调理食品的脱腥工艺、调料配方、灭菌条件,以及适于工业化生产的配方与工艺条件。筛选得出最佳脱腥工艺条件:碳酸氢钠1%,氯化钠1.8%,乙醇5%;最佳调味料配方:食盐2.5%,味精1.5%,白砂糖2.0%,黄酒2.5%,芝麻油3.0%;最佳灭菌条件:温度100℃,时间15 m in。     

响应面法优化浒苔鱼松的加工工艺

以新鲜浒苔、小黄花鱼为主要原料,研究了原料预处理、调味炒制等工艺条件对浒苔鱼松产品的影响。通过正交设计和感官评定,确定小黄花鱼调味料最佳配方为:食盐3.0%,味精0.8%,白糖2.0%,料酒1.0%;小黄花鱼打浆时间4min;应用响应面分析法得到最优生产工艺:小黄花鱼糜、浒苔粉添加量之比为3.85:1,初炒时间14.2min,炒酥时间41.5min。研制出的鱼松风味独特,营养丰富,为二者资源的深加工开辟了一条新的途径。     

即食地瓜参的加工工艺研究及营养分析

采用感官评分对即食地瓜参的生姜水脱腥工艺、调味配方进行优化,获得最佳加工工艺,并对其营养成分和卫生指标进行测定。结果显示,即食地瓜参脱腥时间为15 min最佳,调味配方为白砂糖3.5 g、鸡精2.5 g、酱油2.5 g、食盐3.0 g、食用油20.0 g、胡椒粉0.2g、蒜末18.0 g、生姜18.5 g、料酒7.0 g。制备的即食地瓜参含有丰富蛋白质、必需氨基酸、微量元素等营养物质,卫生指标符合即食海参SC/T 3308-2014标准要求。     

即食海蜇丝加工技术及其调味配方的研究

研究了即食海蜇丝的加工技术及其调味配方的筛选,着重研究了即食海蜇丝的增脆方法和杀菌方法,试验结果表明即食海蜇丝的最佳增脆条件为:在温度为60℃左右的热水中热烫40～60s;有效的杀菌方法为60℃加热辅以紫外线照射。通过正交试验研究4种主要调味料对海蜇丝成品的色、香、味等方面的影响,筛选出即食海蜇丝的最佳配方(按份量计)为:海蜇丝100、酱油2.0、陈醋3.0、辣椒油2.0、蒜泥1.0、花生油1.0、精盐1.5、白糖1.0、味精0.5、鸟苷酸 肌苷酸0.05。     

即食菲律宾蛤仔休闲食品加工工艺研究

为研究即食菲律宾蛤仔休闲食品加工工艺,本文探讨了不同脱腥、腌渍、护色及干燥工艺对蛤制品口感风味、水分含量及产品质构特性的影响,采用单因素和正交优化组合试验确定了菲律宾蛤仔休闲食品的最佳工艺条件。其中,脱腥工艺参数:2.0%茉莉花+2.0%姜汁,时间80 min;腌渍工艺参数:食盐5%、味精2.0%、白砂糖8%,时间4 h;护色工艺参数:D-异抗坏血酸钠0.10%,时间1 h;干燥工艺参数:温度75℃,时间3 h。在该工艺条件下生产的即食菲律宾蛤仔制品,风味独特,口感极佳。     

即食半干虾仁加工技术研究

以凡纳滨对虾（Litopenaeus vannamei）为试验原料,探索半干即食虾仁的加工技术。对蒸煮时间及顺序、调味配方、干制方式及杀菌条件等制作工艺关键步骤进行了研究,制作出风味浓郁、口感良好的半干即食虾仁。最佳的工艺条件为先蒸煮后调味,蒸煮时间为5min,通过正交试验筛选调味配方为1L水需加盐50．0g、糖50．0g、柠檬酸2．0g、味精5．0g,二段干燥,先后于50℃和60cC各烘干1h,80～85℃杀菌处理30rain,此条件下可以较好地保持产品的品质和风味。该研究为对虾的开发利用及提高产品附加值提供了新途径。     

即食型休闲食品“油炸鱼皮”工艺研究

为了对罗非鱼进行高值化综合利用,以提高罗非鱼加工业的经济效益,促进罗非鱼养殖业的发展,根据市场需求,进行了罗非鱼加工废弃物———鱼皮即食休闲食品的工艺研究。通过试验,确定了罗非鱼鱼皮即食型休闲食品的适当调料配方、油炸温度及适于工业化生产的工艺条件。     

调味河鲀休闲制品工艺研究

以河豚鱼肉为原料,开发即食调味河豚鱼片。采用色泽、口感、气味和组织形态的感官评分作为评价指标,在糖用量、盐用量、酱油用量3个单因素试验的基础上,采用响应面法优化调味制备工艺;在最佳工艺制备条件下,以感官分值和质构特性为评价指标确定满足商业无菌要求的最佳杀菌时间。结果显示:在糖用量6.7%、盐用量4.0%、酱油用量4.2%、用水煮香料液补至100%的条件下,预测感官分值高达8.15,感官评分结果为8.40,与预测值接近;确定最佳杀菌时间是15 min。研究表明:即食调味河豚鱼片的制备工艺可行,并可为其他水产制品的深加工提供参考。     

罗非鱼片干的微波烘烤技术

本文以罗非鱼为原料，研究了调味烤罗非鱼片干加工过程中，鲜甜味和鲜辣味两种调味液配方、不同微波炉烘烤方法对产品品质的影响，从而确定了烤罗非鱼片干加工的最佳工艺条件。结果表明，在本工艺条件下制取的烤罗非鱼片干色泽金黄色，口感香脆，有嚼劲，且有烤鱼特有香味。     

条浒苔多糖的酶法辅助提取及其抗氧化活性

以多糖提取率为指标,通过单因素试验确定提取条件,采用均匀设计优化纤维素酶辅助提取,采用普鲁士蓝反应法及Fenton体系测定条浒苔多糖的还原力及对羟自由基的清除活性。试验结果表明,条浒苔多糖的提取条件为料液比1∶20,pH 9.0,温度80℃,时间6h;纤维素酶辅助提取条件为温度25℃,pH 3.0,时间6.5h,料液比1∶5,加酶量0.5%。条浒苔多糖的提取工艺为经酶处理后调整料液比至1∶20,pH及温度调整至9.0及80℃,提取6h,在此条件下多糖提取率为31.05%～37.41%。条浒苔多糖的还原力及羟自由基清除率EC50分别为32.79mg/mL和4.10mg/mL。     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.     

Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China

Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.     

Evaluation of a Fast Method Based on the Presence of Two Restriction Sites in the Mitochondrial ND5 (mt ND5) Gene for the Identification of Scomber Species

The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.     

Growth hormone (GH) and reproduction: a review

Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.     

Purification and partial characterization of GtHs (cfLH and cfFSH) from Indian walking catfish (Clarias batrachus) (L.) and development of a homologous ELISA for cfLH

Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL^?1 (1.25 ng well^?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.     

Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection

Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg^?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).