基于电子鼻的海捕与养殖海鲈鱼鉴别技术研究

目的采用电子鼻技术进行海捕与养殖海鲈鱼的鉴别研究。方法采用电子鼻对海捕和养殖海鲈鱼(Lateolabrax japonicus)的背肉、腹肉、鱼鳃和鱼皮4个部位的气味信息进行提取,采集了冰鲜(0℃)、水煮(100℃)和烘烤(180℃)处理后4个部位气味指纹的变化,通过主成分分析和雷达图表征区分海捕与养殖海鲈鱼。结果对于冰鲜样品,电子鼻不仅能区分出海捕和养殖的海鲈鱼,还能有效地区分出海鲈鱼的不同部位。对于水煮样品,电子鼻能根据背肉和腹肉的气味特征,区分海鲈鱼样品来自海捕还是养殖。对于烘烤样品,电子鼻仅能区分出样品的部位。随着处理温度的不断提高,海捕和养殖海鲈鱼的气味差别逐渐消失,背肉和腹肉能较稳定地反应两者之间的差别,可作为电子鼻鉴别的靶点。结论与传统感官评价相比,电子鼻在海捕与养殖海鲈鱼鉴别的准确度和区分效率上更具有显著优势。     

基于转录组学的养殖密度影响斑节对虾品质的分子机制

采用高通量转录组测序和实时定量聚合酶链式反应（quantitative real time polymerase chain reaction，qRT-PCR）技术，在分子水平揭示养殖密度对斑节对虾肌肉品质形成的影响机制。选取养殖密度100 尾/m2、300 尾/m2的斑节对虾为实验材料，进行转录组测序和qRT-PCR验证。结果表明：所有样本Q20和Q30的最小值均大于90%，测序数据均满足生物信息学分析的要求；不同密度养殖条件下，斑节对虾的差异表达基因为778 个；将差异基因序列与7个数据库进行比对，得到不同密度养殖的斑节对虾中与肌肉品质相关的差异基因分布在胶原蛋白代谢、蛋白水解、蛋白转运、细胞蛋白代谢、细胞骨架组织、肌肉连接及葡萄糖代谢途径；qRT-PCR验证结果与转录组测序结果一致。     

凡纳滨对虾的加工利用和产业发展概述

凡纳滨对虾是当今高产的三大养殖对虾品种之一,具有广温广盐杂食性、生长速度快、抗病抗逆力高、适应性能强、营养需求低等突出特点,是一种营养均衡的食源性高蛋白佳品。凡纳滨对虾从1988年引进中国后,90年代初养殖获得成功,2000年后进行了规模化推广,2019年养殖总产量为181.6万吨t,逐步成为我国对虾养殖的主要品种和渔业经济的重要支柱产业,并且形成了从引种、繁苗、养殖、加工、销售等环节的庞大产业链,产生了巨大的经济效益、社会效益、生态效益以及文化效益。目前我国对虾加工产业处于结构简单、粗放加工的初级阶段,加上国际贸易壁垒、国内外市场低迷、成本过高等诸多因素,进行虾类高值化产品研究、加工技术研究、延长虾类加工产业链等已成为产业发展方向,这对开辟凡纳滨对虾加工食品新途径、促进虾产业的可持续发展具有重要意义。     

冰温技术结合生物保鲜剂对中国对虾品质的影响

利用冰温结合生物保鲜剂涂膜中国对虾,以菌落总数(TVC)、pH、硫代巴比妥酸(TBA)、挥发性盐基氮含量(TVB-N)、感官评价、肌动球蛋白盐溶性及质构特性为指标,研究冰温结合生物保鲜剂涂膜对中国对虾贮藏品质的影响。结果表明:中国对虾冰温带为-2.2~0 ℃;冰温技术结合复合生物保鲜剂涂膜的中国对虾相比于冷藏空白组、冰温其他组,TVC、pH、TBA、TVB-N、肌动球蛋白盐溶性上升缓慢;感官品质得到更有效保持。同时,质构分析也表明冰温结合复合生物保鲜剂涂膜对中国对虾的保鲜效果优于其他组别,效果最佳。各指标说明冰温结合复合生物保鲜剂能有效抑制中国对虾的细菌生长,并有效减缓脂肪等氧化变质;通过对各指标进行分析,冰温结合复合生物保鲜剂组相比冷藏(4±1)℃处理组货架期延长6~8 d,相比冰温空白组延长4~6 d。     

T-2毒素对凡纳滨对虾肌肉蛋白质含量与组成的影响

以凡纳滨对虾为研究对象,采用肌肉蛋白质分离法提取蓄积染毒的染毒组和对照组中对虾肌肉的各类蛋白质成分。以考马斯亮蓝法测定其含量,应用SDS-PAGE电泳分析各类蛋白的组成。结果表明:T-2毒素对肌肉蛋白质组成成分影响显著(P0.05);对于总蛋白,20 d蓄积染毒组和生物半衰期剂量组的对虾总蛋白中20.1ku条带的颜色变化随T-2毒素浓度的增加逐渐加深,且20 d蓄积染毒的高剂量组在29 ku处出现新增条带;对于水溶性蛋白,20 d蓄积染毒组的42 ku条带的颜色随T-2毒素浓度的增加逐渐加深,而生物半衰期剂量组的对虾则没有明显表现;对于肌原纤维蛋白,20 d蓄积染毒组的42 ku出现新增的条带,而生物半衰期剂量组未发现新增条带;对于碱溶性蛋白,两种染毒组均未发现明显变化。     

T-2毒素对不同生长期对虾的急性毒性及其分析方法的比较研究

比较T-2毒素对不同生长期凡纳滨对虾(Litopenaeus vannamei)的急性毒性及其分析方法,明确对虾作为T-2毒素毒性评价的生物标记物的最佳时期,建立T-2毒素对对虾的急性毒性互补评价方法。通过对不同生长期凡纳滨对虾的急性毒性试验,采用寇氏法和概率单位法,计算得到T-2毒素对不同生长期凡纳滨对虾的LD50,并通过u检验对两种方法求得的LD50值进行分析比较。结果得到T-2毒素对虾卵、幼虾和成虾的LD50值分别为2.33、1.79和3.34 mg/kg·bw,且经检验两种方法求得的LD50并无显著性差异。研究表明,T-2毒素对成虾的毒害作用最小急性毒性最弱,对幼虾的毒害作用最大急性毒性最强,即该生长期的凡纳滨对虾更适宜做评价T-2毒素急性毒性的生物标志物,同时采用寇氏法和概率单位法相结合的方法得到的LD50值更具准确。     

电子鼻检测复合涂膜对中国对虾保鲜的影响

利用壳聚糖、ε-聚赖氨酸、卡拉胶对中国对虾进行涂膜,研究电子鼻对不同涂膜处理的中国对虾气味响应,并与感官评价、挥发性盐基氮(TVB-N)进行对比分析,建立一种基于电子鼻技术的对虾新鲜度评价方法。研究结果显示,电子鼻能够区分不同涂膜处理的中国对虾,且结果与感官评价、TVB-N值结果一致。此外,负荷加载分析(Loadings)显示,不同传感器对主成分的贡献率不同,传感器W1W(无机硫化物)和W2W(有机硫化物)对第一主成分贡献率较大,W5S(氮氧化合物)和的W1S(烃类物质)传感器对第2主成分贡献率较大。电子鼻对中国对虾贮藏期间气味有较好的响应,因此可以采用电子鼻系统评价中国对虾的新鲜度。     

免疫印迹法对四种海虾主要过敏原的鉴定

以凡纳滨对虾、中国明对虾、刀额新对虾以及虾蛄4 种海虾为研究对象,对这4 种海虾过敏原蛋白组分进行研究。首先利用聚丙烯酰胺凝胶电泳对4 种海虾过敏原组分进行分析,然后经免疫印迹鉴定其主要过敏原。结果显示：凡纳滨对虾的主要过敏原为99、33、19、14kD 的蛋白质组分;中国明对虾的主要过敏原为39、33、28kD 的蛋白质组分;刀额新对虾的主要过敏原为33kD 和24kD 的蛋白质组分;虾蛄的主要过敏原为56kD 和48kD的蛋白组分。     

生物标志物在水产品检测中的应用

水产品检测是保障水产品质量安全的重要手段。与传统的有毒有害物质化学检测方法相比,生物标志物检测方法在关于有毒污染物对生物体健康的影响方面可以给出更完全的信息,具有较高的灵敏度和可靠性。生物标志物已广泛应用于医学、环境科学、毒理学等学科研究,成为不同领域的研究热点。本文介绍了利用不同生物标志物进行水产品质量安全检测的原理及方法,综述了乙酰胆碱酯酶(ACh E)、腺苷三磷酸酶(ATPase)、谷胱甘肽硫转移酶(GSTs)、抗氧化酶、细胞色素P450、金属硫蛋白(MT)、热激蛋白HSP70、卵黄蛋白原(VTG)和DNA损伤等多种生物标志物在水产品检测中的应用及范围,分析了其对不同种类污染物的敏感性及特异性,并对生物标志物在检测领域中的应用进行了展望。     

光合细菌在人工对虾育苗中的应用实验

人工养殖对虾育苗，是对虾养殖的第一个关键环节，它对提高对虾养殖的整体效益十分重要。本文从光合菌对育苗的应用机理、实验方法及实验结果，总结分析了光合菌在对虾育苗中所起的作用，并对有关文献的报道提出了讨论意见。     

Lipid composition and contaminants in farmed and wild salmon

Levels of omega-3 (n-3) and omega-6 (n-6) fatty acids and lipid-adjusted concentrations of polychlorinated biphenyls (PCBs), dioxins, toxaphene, and dieldrin were determined in 459 farmed Atlantic salmon, 135 wild Pacific salmon, and 144 supermarket farmed Atlantic salmon fillets purchased in 16 cities in North America and Europe. These were the same fish previously used for measurement of organohalogen contaminants. Farmed salmon had greater levels of total lipid (average 16.6%) than wild salmon (average 6.4%). The n-3 to n-6 ratio was about 10 in wild salmon and 3-4 in farmed salmon. The supermarket samples were similar to the farmed salmon from the same region. Lipid-adjusted contaminant levels were significantly higher in farmed Atlantic salmon than those in wild Pacific salmon (F = 7.27, P = 0.0089 for toxaphene; F = 15.39, P = 0.0002 for dioxin; F > or = 21.31, P < 0.0001 for dieldrin and PCBs, with df = (1.64) for all). Levels of total lipid were in the range of 30-40% in the fish oil/fish meal that is fed to farmed salmon. Salmon, especially farmed salmon, are a good source of healthy n-3 fatty acids, but they also contain high concentrations of organochlorine compounds such as PCBs, dioxins, and chlorinated pesticides. The presence of these contaminants may reduce the net health benefits derived from the consumption of farmed salmon, despite the presence of the high level of n-3 fatty acids in these fish.     

野生与养殖鳡鱼肌肉的营养成分比较

对野生鳡鱼和养殖鳡鱼的营养品质进行研究。结果表明：这两种鱼肌肉中水分含量差异不显著(P＝0.07779＞0.05),而粗蛋白、粗灰分含量野生鳡鱼显著高于养殖鳡鱼(P＝0.00115、0.00415＜0.05),养殖鳡鱼粗脂肪含量显著高于野生鳡鱼(P＝0.000215＜0.05)。养殖鳡鱼的必需氨基酸指数为94.16,而野生鳡鱼则为66.03,其构成比例符合联合国粮农组织/世界卫生组织(FAO/WHO)的标准。野生和养殖鳡鱼肌肉脂肪酸中二十碳五烯酸(EPA)+二十二碳六烯酸(DHA)含量分别为4.25%和4.8%。综合所得结果,养殖鳡鱼氨基酸组成及结构、EPA+DHA含量均优于野生鳡鱼,但野生鳡鱼蛋白质含量与n-3/n-6多不饱和脂肪酸(PUFA)比例优于养殖鳡鱼。     

野生和养殖乌鳢肌肉的成分分析及营养评价

本文对野生和养殖乌鳢肌肉中的营养成分进行了分析和营养评价。结果表明:野生乌鳢肌肉中粗脂肪含量显著低于养殖乌鳢(P0.05)。野生乌鳢n-3多不饱和脂肪酸含量和c22:6(DHA)含量均高于养殖乌鳢,野生和养殖乌鳢肌肉中n-3/n-6的比例分别为1.21和0.65。两种乌鳢肌肉都检测到了17种氨基酸,养殖乌鳢肌肉中氨基酸总量、鲜味氨基酸含量、必需氨基酸含量均高于野生乌鳢,野生和养殖乌鳢肌肉中必需氨基酸/总氨基酸(EAA/TAA)的比值分别为42.66%和42.28%,必需氨基酸/非必需氨基酸(EAA/NEAA)的比值分别为74.40%和73.26%,均高于FAO/WHO推荐的理想蛋白质模式,野生和养殖乌鳢肌肉的必需氨基酸评分(EAAI)分别为63.48和70.82。两种乌鳢肌肉中矿物质元素均以钾最高,养殖乌鳢微量元素含量显著高于野生乌鳢(P0.05)。因此,以低值野杂鱼饵料为食物来源的养殖乌鳢具有良好的开发前景。     

野生与池养刀鲚肌肉品质特性及抗氧化性的比较分析

比较研究了野生和池养刀鲚（Coilia nasus）肌肉营养成分组成、质构特性和抗氧化特性。结果显示,野生刀鲚肌肉中水分、羟脯氨酸、胶原蛋白含量以及胶原蛋白/总蛋白比值均显著低于池养型,而脂肪含量则显著提高;两者的蛋白质含量、pH均无显著性差异;池养刀鲚肌肉弹性、硬度、咀嚼度、胶着性相较于野生型呈上升趋势,但无统计学差异。野生刀鲚肌肉中SOD、CAT、T-AOC、MDA、GSH-PX、iNOS、GSH/GSSG均显著高于池养型。表明野生和池养刀鲚营养品质存在差异,建议在人工养殖刀鲚中应该注意饵料的种类和丰度,其养殖模式有待进一步改善。     

Comparative study of proximate composition and amino acid in farmed and wild Pseudobagrus ussuriensis muscles

The proximate composition and amino acid compositions of the muscle of wild and farmed Pseudobagrus ussuriensis were compared. The lipid content of the farmed fish was significantly higher, while moisture content was significantly lower, than those of the wild fish. Pseudobagrus ussuriensis protein has a well‐balanced amino acid composition. The percentages of total amino acids, essential amino acids, nonessential amino acids and delicious amino acids were significantly higher in the wild than those in farmed fish. The ratios of W_EAA to W_TAA (42.78%–43.02%) and W_EAA to W_NEAA (85.52%–87.74%) were comparable to the reference values of 40% and above 60% recommended by FAO/WHO. According to the amino acid scores, methionine would have been described as the first limiting amino acid, and Lys had the highest score for the protein in both wild and farmed Pseudobagrus ussuriensis. This study shows that Pseudobagrus ussuriensis under investigation have high nutritional qualities and are good protein resources.     

养殖和野生长吻鮠肌肉营养成分比较分析

采用常规生化分析方法对养殖和野生长吻鮠肌肉营养成分进行分析,并对其营养品质进行评价。结果表明,养殖长吻鮠水分极显著高于野生长吻鮠（P＜0.01）,蛋白质、脂肪极显著低于野生长吻鮠（P＜0.01）;养殖长吻鮠氨基酸总量（干基）显著高于野生长吻鮠（P＜0.05）,必需氨基酸无显著差异（P＞0.05）,氨基酸组成均完全符合联合国粮食及农业组织/世界卫生组织标准,鲜味氨基酸总量极显著高于野生长吻鮠（P＜0.01）;单不饱和脂肪酸总量极显著低于野生长吻鮠（P＜0.01）,n-6多不饱和脂肪酸总量极显著高于野生长吻鮠（P＜0.01）,n-3多不饱和脂肪酸总量无显著差异（P＞0.05）,致动脉粥样硬化指数、血栓形成指数无显著差异（P＞0.05）。研究表明,与野生长吻鮠相比,养殖长吻鮠营养品质没有降低,通过调整饲料配方,可进一步提高养殖长吻鮠的营养品质。     

Comparative assessment of proximate composition,physicochemical parameters,fatty acid profile and mineral content in farmed and wild rainbow trout (Oncorhynchus mykiss)

This study was conducted to determine differences between farmed and wild rainbow trout in terms of proximate and fatty acid composition, physicochemical parameters and mineral content. Fat content of farmed fish fillets was higher, while moisture content was lower than wild fish. However, wild fish had higher pH value and water‐holding capacity comparing to farmed fish. The muscle lipids of farmed fish contained higher proportions of 20:0, 18:1n‐9 and 20:1n‐9; and lower proportions of 18:2n‐6, 20:2cis, 18:3n‐3, 20:3n‐6, 20:4n‐6, 20:5n‐3 and 22:6n‐3 fatty acids than wild fish. The percentage of total saturated fatty acids (SFAs) was similar in both fish. Total polyunsaturated fatty acids (PUFAs), n‐3 PUFAs and n‐3/n‐6 PUFAs ratio were higher in the wild fish comparing to farmed fish, whereas its total monounsaturated fatty acids (MUFAs) and n‐6 PUFAs contents were lower. Among the seventeen minerals analysed in fish flesh, differences existed between farmed and wild rainbow trout in Ca and Fe contents. Moreover, toxic trace minerals (As, Cd, Pb and Hg) were all present in amounts below their toxic levels. The differences observed between farmed and wild fish may be attributed to the diet constituents and environmental conditions of the fish.     

High resolution two-dimensional electrophoresis as a tool to differentiate wild from farmed cod (Gadus morhua) and to assess the protein composition of klipfish

Tris and CHAPS–urea extracts from wild and farmed cod muscle and from rehydrated cod klipfish fillets were analyzed by one (1DE) and two-dimensional electrophoresis (2DE). 2DE maps of tris extracts from farmed cod differed from the wild in a series of spots of Mw 35 and 45 kDa. The CHAPS–urea extracts from farmed cod had a several spots of Mw between 100 and 45 kDa, which were hardly detectable in wild cod and very prominent in klipfish. Klipfish was clearly different from the other samples: the myosin heavy chain was hardly detectable in these samples, and the tris extracts contained fewer, and the CHAPS–urea more spots than the corresponding extracts from the raw muscles. Further identification of these potentially diagnostic spots will make it easier the differentiation of farmed from wild cod and the evaluation of klipfish processing on the protein content of the product.     

Process control of lightly salted wild and farmed Atlantic cod (Gadus morhua) by brine injection, brining, and freezing--a low field NMR study

The aim of this study was to use low-field nuclear magnetic resonance (NMR) and traditional chemical methods to investigate the physical and chemical differences in wild and farmed cod processed pre- and postrigor, and how these properties were affected by brine injection, brining, and freezing. In prerigor processed farmed or wild cod, brine injections followed by brining for 2 d, with brine concentrations up to 5.5% and 4%, respectively, were not sufficient to reach a muscle salt concentration of 2% as aimed for, while wild cod processed postrigor had sufficient salt uptake after the same processing. Low-field NMR gave valuable information about the differences in the muscle structure between wild and farmed cod as well as the state of the water in the muscle during brine injection, brining, and during rigor tension. Low-field NMR is, therefore, a valuable tool that can be used to optimize the salting and storing processes of lightly salted cod products from both wild and farmed cod. For farmed cod to be used in the production of lightly salted products further research is needed. Practical Application: Optimal processing of lightly salted cod products is important to the fish industry, due to an increasing market for this product in southern Europe. Farmed cod, which is seen as a potential steady raw material source for this production, differs considerably from its wild counterparts by having other chemical and physical muscle properties, such as lower water content and lower pH. With the processing procedures used today the farmed cod can, therefore, only be used in some of the products, where wild cod is currently used as raw material. It is, therefore, important that the processing of these products is optimized with regard to these differences in the raw material. This study gives a valuable contribution to further studies about optimal combinations of brine injections, brining, and freezing of pre- and postrigor processed farmed compared to wild cod.     

The Effects of Essential Oils Addition on the Quality of Wild and Farmed Sea Bream (<Emphasis Type="BoldItalic">Sparus aurata</Emphasis>) Stored in Ice

The preservative effect of laurel (Laurus nobilis) and cumin (Cuminum cyminum) essential oils (EOs) on fresh vacuum-packed (VP) wild and farmed sea bream (Sparus aurata) fillets was evaluated during ice storage by microbiological, physicochemical and electrophoretic analyses. In the present study, wild (W) and farmed (F) fillet treatment included the following lots: control vacuum-packaged samples (WV and FV), VP with added EOs (0.5% v/w) of cumin (WVC and FVC), and of laurel (WVL and FVL). Wild and cultured fish were found to differ significantly in their muscle proximate compositions irrespective of fillet treatments with particularly higher fat and carbohydrate contents in farmed sea bream (4.82 and 0.32 g/100 g, respectively, vs. 1.53 and 0.22 g/100 g in wild fish). The treatment of wild and farmed sea bream fillets with laurel or with cumin EOs induced a decrease in bacterial growth by ca. 0.5 to 1 log cfu/g and in lipid oxidation by ca. 40% of TBA value, extending the shelf life of fish fillets by approximately 5 days of ice storage. However, the addition of EOs to VP fillets resulted in a reduced liquid holding capacity (LHC) throughout ice storage suggesting an early proteolysis initiation confirmed by the myofibrillar and sarcoplasmic electrophoretic profiles. Laurel and cumin EOs as natural and efficient antibacterial and antioxidant compounds can be used in conjunction with VP to enhance ice-stored sea bream quality.