南极磷虾油的浓缩工艺对虾青素含量的影响

以磷虾油中的虾青素含量为评价指标,对浓缩工艺中加热温度、加热时间、真空度等浓缩条件进行考察,找到影响虾油中虾青素含量的关键因素,明确各因素对虾青素含量的影响大小,并结合生产实际,最终确定最佳浓缩工艺为真空度-0.1 MPa,加热温度为50℃,加热时间为3 h。     

Growth, feed conversion and chemical composition of Atlantic salmon (Salmo salar L.) and Atlantic halibut (Hippoglossus hippoglossus L.) fed diets supplemented with krill or amphipods

The effects of partial replacement of fish meal (FM) with meal made from northern krill (Thysanoessa inermis), Antarctic krill (Euphausia superba) or Arctic amphipod (Themsto libellula) as protein source in the diets for Atlantic salmon (Salmo salar L.) and Atlantic halibut (Hippoglossus hippoglossus L.) on growth, feed conversion, macro‐nutrient utilization, muscle chemical composition and fish welfare were studied. Six experimental diets were prepared using a low‐temperature FM diet as control. The other diets included northern krill where 20, 40 or 60% of the dietary FM protein was replaced with protein from northern krill, and two diets where the FM protein was replaced with protein from Antarctic krill or Arctic amphipod at 40% protein replacement level. All diets were iso‐nitrogenous and iso‐caloric. Atlantic salmon grew from 410 g to approximately 1500 g during the 160 day experiment, and Atlantic halibut grew from 345 g to 500–600 g during the 150 day experiment. Inclusion of krill in the diets enhanced specific growth rate in salmon, especially during the first 100 days (P < 0.01), and in a dose–response manner in halibut for over the 150 day feeding period (P < 0.05). Feed conversion ratio did not differ between dietary treatments, and no difference was found in dry matter digestibility, protein digestibility and fish muscle composition. Good growth rates, blood parameters within normal ranges and low mortalities in all experimental treatments indicted that fish health was not affected either Atlantic salmon or Atlantic halibut fed the various zooplankton diets.     

常温酶解法测定基于南极磷虾中虾青素酯的方法研究

由于虾青素酯具有多种存在形态,其准确定量还存在难点,将其有效转化成可定量的游离态是解决问题的关键.本实验将南极磷虾作为不同形态虾青素研究的代表性品种,采用柱层析法从南极磷虾中分别制备了虾青素的单酯和双酯,明确了其组成和含量,作为典型特征样品,进一步通过单因素和正交实验优化确立最佳酶解条件,并对方法的准确性和适用性进行了...     

Advances in Technologies for Highly Active Omega-3 Fatty Acids from Krill Oil: Clinical Applications

Euphausia superba, commonly known as krill, is a small marine crustacean from the Antarctic Ocean that plays an important role in the marine ecosystem, serving as feed for most fish. It is a known source of highly bioavailable omega-3 polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid). In preclinical studies, krill oil showed metabolic, anti-inflammatory, neuroprotective and chemo preventive effects, while in clinical trials it showed significant metabolic, vascular and ergogenic actions. Solvent extraction is the most conventional method to obtain krill oil. However, different solvents must be used to extract all lipids from krill because of the diversity of the polarities of the lipid compounds in the biomass. This review aims to provide an overview of the chemical composition, bioavailability and bioaccessibility of krill oil, as well as the mechanisms of action, classic and non-conventional extraction techniques, health benefits and current applications of this marine crustacean.     

基于物种分布集成模型的布兰斯菲尔德海峡南极磷虾栖息地研究

南极磷虾为南大洋海洋生态系统中的关键物种,但目前关于该物种栖息地研究仍较为有限,这不利于对该物种分布的理解以及资源管理.实验利用南极磷虾资源密度数据与海表面温度、海表面叶绿素、海表面高度、净初级生产力和季节性海冰覆盖等5个环境因素,通过12种算法的集成模型对南极磷虾栖息地进行分析.结果显示,支持向量机、随机森林、多元自...     

南极磷虾粉氨基酸营养价值分析与评价

试验旨在评价南极磷虾粉氨基酸营养价值。采用国标方法,测定南极磷虾粉中氨基酸含量及组成,并将12种水产动物肌肉氨基酸组成作为参考模式,评价南极磷虾粉作为饲料蛋白源的氨基酸营养价值,并与鱼粉和豆粕进行比较。试验结果表明：南极磷虾粉中总氨基酸、必需氨基酸和呈味氨基酸分别占干物质总重的67.18%、32.64%和23.73%,必需氨基酸和呈味氨基酸分别占氨基酸总量的48.59%和35.32%,必需氨基酸和非必需氨基酸的比值为94.50,符合FAO/WHO的理想蛋白质模式。通过氨基酸比值系数法计算,南极磷虾粉第一限制性氨基酸主要为蛋氨酸,而在所选的水产动物中,南极磷虾粉适合作为点篮子鱼、黄颡鱼和红鳍东方鲀的饲料蛋白源。南极磷虾粉氨基酸平衡性较好,营养价值较高,是一种值得开发利用并在水产动物饲料中应用的优质资源。     

南极磷虾粉替代鱼粉对黄颡鱼生长、免疫及肌肉品质的影响

为研究南极磷虾粉替代鱼粉对黄颡鱼生长性能、血清免疫指标及肌肉品质的影响,实验以初始体质量为(10.51±0.13)g的黄颡鱼为研究对象,南极磷虾粉替代基础饲料(30％鱼粉)中0％(KM0,对照组)、2.5％(KM2.5)、5.0％(KM5)、7.5％(KM7.5)和10％(KM10)的鱼粉,共配制5组等氮等脂的饲料,每...     

南极磷虾粉替代鱼粉对圆斑星鲽幼鱼生长性能、血清和肝脏生化指标及血清非特异性免疫指标的影响

本试验旨在探究南极磷虾粉替代鱼粉对圆斑星鲽幼鱼生长性能、血清和肝脏生化指标及血清非特异性免疫指标的影响。以鱼粉和玉米蛋白粉为蛋白质源,高筋粉为糖源,鱼油、豆油和磷脂为脂肪源配制基础饲料。以南极磷虾粉分别替代基础饲料中0(对照)、10%、20%、30%、40%、50%的鱼粉,配制6种等氮等脂的试验饲料(分别记为R0、R10、R20、R30、R40和R50),饲喂初始体重为(38.16±0.11)g的圆斑星鲽幼鱼50 d,每种饲料设3个重复,每个重复投喂30尾鱼。结果表明:1)R30、R40组圆斑星鲽幼鱼的增重率和饲料效率较高,显著高于其他各组(P0.05);R50组的死亡率显著高于其他各组(P0.05)。南极磷虾粉替代鱼粉水平对圆斑星鲽幼鱼的肝体比和脏体比没有产生显著影响(P0.05)。2)R10和R30组的血清总蛋白含量显著高于其他各组(P0.05);与对照组相比,南极磷虾粉替代10%~30%的鱼粉对圆斑星鲽幼鱼血清中谷草转氨酶和谷丙转氨酶以及肝脏中谷氨酸脱氢酶活性无显著影响(P0.05)。R40、R50组血清中谷草转氨酶和谷丙转氨酶活性与对照组相比显著升高(P0.05),R40组肝脏中谷草转氨酶活性较之对照组显著降低(P0.05),且R50组肝脏中谷丙转氨酶活性显著低于其他各组(P0.05)。3)与对照组相比,南极磷虾粉替代10%~30%的鱼粉可显著提高圆斑星鲽幼鱼血清中溶菌酶、碱性磷酸酶的活性(P0.05)。综合来看,南极磷虾粉替代10%~30%的鱼粉可以提高圆斑星鲽幼鱼的生长性能和非特异性免疫力,并对鱼体的肝脏功能和蛋白质代谢无不利影响。     

船舶摇摆和工艺参数对南极磷虾挤压脱壳效果的影响

为了探究风浪造成的船只摇摆和工艺参数设置对南极磷虾挤压脱壳加工效果的影响,该文测量记录了不同横摇和纵摇状态下脱壳加工的得肉率和虾壳残留,分析了不同条件下脱壳滚轴长度区域的脱壳完成率。结果表明:船舶摇摆会对脱壳加工得肉率与虾壳残留率造成影响,但差异均不显著(P0.05),在纵摇7?和横摇5?时虾壳残留率分别达到1.07%和1.64%。船舶的摇摆对脱壳完成率有一定影响,随着摇摆幅度的增加,同一区域内脱壳完成率呈下降趋势。增加滚轴的长度能有效防止由于摇摆幅度增加而造成脱壳完成率降低的问题,当滚轴长度为1 200 mm时,脱壳完成率大于95%。放置时间对脱壳效果的影响较大(P0.05),放置2 h后的磷虾在区域Ⅳ的脱壳完成率降低至94%,虾壳残留率也相应增多。研究结果可为南极磷虾脱壳设备的应用和产业化提供参考。     

Ecosystem modelling to quantify the impact of historical whaling on Southern Hemisphere baleen whales

Many baleen whales were commercially harvested during the 20th century almost to extinction. Reliable assessments of how this mass depletion impacted whale populations, and projections of their recovery, are crucial but there are uncertainties regarding the status of Southern Hemisphere whale populations. We developed a Southern Hemisphere spatial “Model of Intermediate Complexity for Ecosystem Assessments” (MICE) for phytoplankton, krill (Euphausia superba) and five baleen whale species, to estimate whale population trajectories from 1890 to present. To forward project to 2100, we couple the predator–prey model to a global climate model. We used the most up to date catch records, fitted to survey data and accounted for key uncertainties. We predict Antarctic blue (Balaenoptera musculus intermedia), fin (Balaenoptera physalus) and southern right (Eubalaena australis) whales will be at less than half their pre‐exploitation numbers (K) even given 100 years of future protection from whaling, because of slow growth rates. Some species have benefited greatly from cessation of harvesting, particularly humpbacks (Megaptera novaeangliae), currently at 32% of K, with full recovery predicted by 2050. We highlight spatial differences in the recovery of whale species between oceanic areas, with current estimates of Atlantic/Indian area blue (1,890, <1% of K) and fin (16,950, <4% of K) whales suggesting slower recovery from harvesting, whilst Pacific southern right numbers are <7% of K (2,680). Antarctic minke (Balaenoptera bonaerensis) population trajectories track future expected increases in primary productivity. Population estimates and plausible future predicted trajectories for Southern Hemisphere baleen whales are key requirements for management and conservation.