养殖海水和淡水鲈鱼的营养组成比较分析

为分析大宗养殖海水鲈鱼和淡水鲈鱼的营养组成,有助于后续开发加工,本文对养殖海水鲈鱼(海鲈鱼)和淡水鲈鱼(大口黑鲈)肌肉的常规营养成分、氨基酸组成、脂肪酸组成、无机盐、微量元素和有毒有害物质进行测定和分析比较。结果表明,海水养殖的海鲈鱼营养价值比淡水养殖的大口黑鲈高,其蛋白质含量显著比大口黑鲈高(p<0.01);两种养殖鲈鱼均含有人体所必需的优质氨基酸,海鲈鱼氨基酸总量显著比大口黑鲈高(p<0.05),且各种氨基酸含量均略高于大口黑鲈,鲜味氨基酸中谷氨酸含量最高,海鲈鱼的肉味更鲜甜。海鲈鱼肌肉脂肪含量与大口黑鲈相近,但内脏脂肪含量显著比大口黑鲈高(p<0.01)。海鲈鱼肌肉中不饱和脂肪酸含量显著比大口黑鲈高(p<0.01),但二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)含量均低于大口黑鲈(p<0.01),大口黑鲈是人体补充EPA和DHA的优质食用鱼类。鲈鱼的矿物元素含量均很丰富,特别是富含钙和微量元素锌,而养殖海水鲈鱼在无机盐和微量元素含量方面均优于淡水鲈鱼。      

基于高通量测序分析不同保鲜冰处理对鲈鱼菌群组成与代谢功能的影响

目的：分析不同保鲜冰处理下鲈鱼微生物菌群变化及其与品质指标的相关性。方法：分别采用流化冰（slurry ice,SI）、酸性电解水冰（acidic electrolyzed water ice,AEWI）和碎冰（crushed ice,CI）对鲈鱼进行处理,测定鲈鱼的总挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量与K值,并利用高通量测序技术对样品菌群结构和代谢功能进行比较分析。结果：SI和AEWI对鲈鱼均有一定的保鲜作用,其中SI抑制鲈鱼蛋白质和核苷酸降解速度的效果最显著。在冰藏前期（0～3 d）,AEWI与CI组样品中芽孢杆菌属（Bacillus）、乳球菌属（Lactococcus）、大洋芽孢杆菌属（Oceanobacillus）相对丰度明显高于SI组。冰藏中、后期（12～21 d）,SI组样品中假单胞菌属（Pseudomonas）、希瓦氏菌属（Shewanella）、摩替亚氏菌属（Moritella）、埃希氏杆菌属（Escherichia）和别弧菌属（Aliivibrio）相对丰度明显增加,AEWI组样品假单胞菌属（Pseudomonas）和不动杆菌属（Acinetobacter）相对丰度所占比例逐渐增大,CI组中不动杆菌属在21 d时达27.77%,成为造成鲈鱼贮藏中、后期腐败的主要菌属。主成分分析表明,冰藏方式及贮藏时间对鲈鱼菌群结构组成有较大影响。鲈鱼菌群中与TVB-N含量、K值呈正相关的有假单胞菌属、不动杆菌属、嗜冷杆菌属（Psychrobacter）和希瓦氏菌属,它们可能是鲈鱼冰藏期间的优势菌。CI和AEWI组鲈鱼细菌中参与氨基酸、脂质和碳水化合物代谢的相关基因相对丰度高于同一时期的SI组,这在一定程度上从细菌代谢水平解释了SI能延缓鲈鱼腐败的原因,为后期进一步从微生物抑制机制上优化鲈鱼贮藏保鲜技术提供了理论参考。     

Primary and secondary metabolite compounds in cowpea seeds resistant to the cowpea bruchid [Callosobruchus maculatus (F.)] in postharvest storage

Cowpea is a one important legume crop in Sub-Saharan Africa due to its high content of protein and other nutrients. However, seeds of cowpea varieties are destroyed by Callosobruchus maculatus in storage. This study investigated various biochemical compounds of susceptible and resistant cowpea genotypes, to determine the biochemical compounds underlying cowpea resistance to bruchid. Six cowpea genotypes were analyzed in three replicates. One-way analysis of variance, Pearson correlation and path analysis were used to determine the influence of the biochemical compounds on the cowpea status. Amongst the cowpea genotypes assayed the biochemical compounds analyzed (Vicilin; α-amylase Inhibitor; Phenols; Condensed Tannin; Tannin; Carbohydrate; Flavonoid and Protein), were present in amounts. Resistant genotypes exhibited higher contents of Phenols (22.29 mg/g for WC66*5T and 19.74 mg/g for WC36); Tannin (2.45CEmg/g for WC36 and 2.52CEmg/g for TVU13677); and Carbohydrate (72.82% for TVU13677 and 71.09% for WC36). The most susceptible genotypes had the lowest content of Phenols (13.5 mg/g for TVU946 and 12.72 mg/g for Glessissaffodo); Tannin (0.74CEmg/g for Akounado and 0.97CEmg/g for Glessissaffodo) and Carbohydrate (60.95% for Akounado and 61.39% for TVU946), while Condensed Tannin was associated to their seed coat colour but not to their resistance status against bruchid. The resistant genotypes TVU13677; WC36 and WC66*5T were found to contain a higher amount of a subset of biochemical compounds as defensive compounds against cowpea bruchid. The susceptible cowpea genotypes (Akounado; Glessissaffodo; TVU946) screened for their biochemical content presented low amounts of these defensive compounds. The path analysis implemented highlighted the existence of causal relationships among biochemical compounds analyzed and resistance parameters, thus revealing the resistance basis of cowpea seed biochemical compounds. These latter results point out the possibilities to consider the presence of these biochemical compounds underlying the resistance of cowpea to bruchid in the breeding program toward the resistance to bruchid.     

甲嘧磺隆对两种滩涂动物的急性致毒试验

本文生要研究了甲嘧磺隆对鲈鱼、蛏两种主要的滩涂养殖生物进行了急性毒性研究,为甲嘧磺隆用于滩涂防治互花米草提供科学依据。结果表明：处理96h后对于鲈鱼和蛏的半致死浓度（LC50）分别为151．322和374．450mg／L,甲嘧磺隆对两种实验动物急性毒性属于低毒,对于两种滩涂养殖动物在急性毒性方面没有明显影响。     

Resistance of Vigna unguiculata (cowpea) seeds to Callosobruchus maculatus is restricted to cotyledonary tissues

We have investigated the survival of Callosobruchus maculatus larvae when reared on resistant IT81D 1045 Vigna unguiculata seeds, whose resistance has been associated with variant forms of vicilins. Here, we present data which show that larvae of C. maculatus feeding on embryonic axis of resistant cowpea reach a mass of around 28 times higher than those feeding on cotyledonary tissues. Additionally, incorporation of 5–10% of embryonic axis flour on artificial seeds made of resistant flour restores toxicity of seeds to the bruchid. Vicilins purified from both susceptible and resistant embryonic axis had no deleterious effects either on insect development or on insect survival until a level of 4% of incorporation. In contrast, vicilins from resistant cotyledons show an LD₅₀ (50% lethal dose) and WD₅₀ (half weight dose) of 2%. Total vicilin contents of embryonic axes were around two times lower than in cotyledonary tissues, while proteolytic activities of all four proteinase classes were always higher in the former tissues. By 2D‐PAGE we visualized eight protein spots, which seem to be exclusively found on resistant cotyledons. Copyright © 2006 Society of Chemical Industry     

复热处理的鲈鱼挥发性成分分析

采用电子鼻和SPME-GC-MS联用技术对复热处理的鲈鱼挥发性成分及含量进行测定。结果表明:冷藏过程中,鲈鱼醛类含量呈现先降低后升高的趋势。与冷藏处理相比,复热处理在13 h后壬醛、1-辛烯-3-醇的总峰面积为29.98×10^7,增加了8.8×10^7,说明复热处理加速了鱼肉脂肪氧化,使得腥味增强。电子鼻可以较好地区分出冷藏3 h、8 h、13 h、18 h后鲈鱼肉气味的差别。DFA分析显示冷藏和复热处理均表现出3 h、8 h气味较为接近,13 h、18 h气味较为接近。主成分分析表明,较于冷藏处理,复热处理的鲈鱼随着处理时间的延长,使得鱼肉腥味加重,其中壬醛、1-辛烯-3-醇的特征向量分别为0.810、0.621,成为主要表现腥味的挥发性物质,并且这两种物质是冷藏13 h、18 h复热时鲈鱼的主要挥发性物质。     

响应面法优化海鲈鱼鱼肉脱腥工艺

摘 要: 目的 确定以香菜、薄荷为主要原料制得的复合脱腥液对海鲈鱼鱼肉的最佳脱腥工艺。方法 通过腥度(腥气、腥味)和感官评分(色泽、气味、滋味、质地)对海鲈鱼鱼肉脱腥效果进行评价, 采用单因素试验和响应面实验研究脱腥液浓度、料液比和脱腥时间, 确定最佳脱腥工艺, 并比较脱腥前后海鲈鱼肉主要挥发性成分及三甲胺含量的变化。结果 最佳脱腥工艺为脱腥液浓度4 g/100 mL, 料液比1:3 (g:mL), 脱腥时间43 min, 脱腥后鱼腥味物质戊醛、己醛和庚醛等明显减弱, 增加了2-茨醇、香叶醇和芳樟醇等清香味物质,三甲胺含量明显降低。结论 最佳脱腥工艺可在脱腥同时赋予鱼肉清香味, 绿色天然、方便有效, 可为海鲈鱼鱼肉脱腥工艺提供参考。     

不同剂量电子束辐照对花鲈鱼肉风味的影响

采用1、3、5、7 kGy剂量电子束辐照处理花鲈鱼肉,以挥发性风味物质、游离氨基酸和呈味核苷酸含量为指标,探究辐照剂量对花鲈鱼肉风味的影响。随辐照剂量上升,花鲈鱼肉中的烃类物质相对含量呈下降趋势,醛、酮类物质相对含量上升;电子鼻检测结果显示,辐照后各剂量组气味有明显区别,但1 kGy和3 kGy组、5 kGy和7 kGy组花鲈鱼肉的气味相对接近;随辐照剂量的增加,鱼肉肌苷酸含量不断上升,呈愉快味游离氨基酸/总游离氨基酸、鸟苷酸含量和味精当量值均呈先上升后下降的趋势,并于3 kGy时达到最大值。结合电子束辐照对花鲈鱼肉的保鲜效果,选用3 kGy剂量对花鲈鱼肉进行前处理,在杀菌的同时能最大程度保留鱼肉的良好风味,实验结果可为辐照保鲜花鲈鱼肉提供依据。     

Biological activity of Cassia occidentalis L. against Callosobruchus maculatus (F.) (Coleoptera: Bruchidae)

In developing countries, traditional control methods are commonly used against stored-product insects and mites. In Senegal, the leaves of Cassia occidentalis L. (Caesalpiniaceae) are used to protect cowpea seeds (Vigna unguiculata L. (Walpers)) against Callosobruchus maculatus (Coleoptera: Bruchidae). The biological activity of the leaves, the seeds and oil of C. occidentalis was evaluated in controlled conditions (28 ± 2°C, 45 ± 5% r.h.) against C. maculatus. At the rate of 10% (w/w), both fresh and dry leaves as well as whole and ground seeds had no contact toxicity on the cowpea beetle. In contrast, seed oil induced an increase in mortality of C. maculatus eggs and first larval instar at the concentration of 10 ml/kg cowpea. The basis of the ovicidal and larvicidal activities are discussed in this paper. Several trials using pure compounds have highlighted that several fatty acids (linoleic, oleic and stearic) are responsible for C. occidentalis toxicity. C. occidentalis seed oil did not reduce the oviposition of C. maculatus at 10 ml/kg seed.