盐度对瘤背石磺幼贝存活、生长性能和肌肉生化成分的影响

为探讨盐度对瘤背石磺(Onchidium struma)幼贝生长和肌肉生化成分的影响,用不同盐度水平(5、15、25、35和45)的人工海水饲养瘤背石磺幼贝[干质量(2.96±1.02)g]60 d后测定瘤背石磺生长性能和肌肉营养成分。结果显示:(1)瘤背石磺在盐度25~45时生长良好,成活率在90%以上。同时,在盐度25时增重率、特定生长率和蛋白质效率均显著高于其余各盐度组(P0.05),而饲料系数也显著降低(P0.05)。(2)随着盐度的升高,瘤背石磺肌肉水分显著降低(P0.05),粗灰分呈先下降后上升趋势,但对肌肉钙和磷含量影响差异不显著(P0.05);粗蛋白含量在盐度25时最高,为76.66%,而粗脂肪在高盐度时呈显著上升趋势(P0.05),分别在盐度25和45时含量最低和最高。(3)除了谷氨酸、天门冬氨酸和脯氨酸等呈味氨基酸受盐度影响差异显著外,大多数氨基酸均随着盐度升高呈现先上升后下降的趋势,且在盐度25最高,但差异不显著。(4)盐度对于每一种脂肪酸的影响均差异显著,在盐度5至35范围内,n-3 PUFA和n-6 PUFA均呈现上升趋势,但n-3 PUFA/n-6 PUFA值也逐渐升高。与大多数海水贝类不同的是,瘤背石磺DHA含量远低于EPA。试验结果表明,盐度对瘤背石磺生长性能以及肌肉生化成分有显著影响,适宜的盐度可改善瘤背石磺的肌肉品质和风味。     

大西洋牙鲆幼鱼肌肉组成与营养需求的探讨

测定了养殖大西洋牙鲆幼鱼肌肉中的蛋白质、脂类、灰分等生化组织,并计算了其比能值,分析了肌肉蛋白质中17种常见氨基酸的含量、脂肪酸组成及含量。结果表明:大西洋牙鲆属高蛋白、低脂肪、低比能值鱼类,肌肉氨基酸含量同其它鲆鲽鱼类相比,属中等水平,必需氨基酸和呈味氨基酸的含量较高;肌肉蛋白中氨基酸的支/芳值为2.794;脂肪酸含量中棕榈酸(16∶0)的含量最高,其次为油酸(18∶1 n)和DHA(22∶6 n-3);其EPA(20∶5 n-3)和DHA(22∶6 n-3)的含量较高,营养丰富且平衡良好,是值得推荐的优良养殖品种和食用鱼类。     

瘤背石磺营养成分分析及品质评价

利用常规营养测定方法测定了10只瘤背石磺（Onchidium struma）的营养成分。结果表明，瘤背石磺活体（鲜样）的水分、粗灰分、粗蛋白、粗脂肪质量分数分别为88．78％、3．95％、6．30％和0．63％。其肌肉中含17种氨基酸，总质量分数为55．77％（脱脂干样），其中，7种人体必需氨基酸总含量为15．63％，占氨基酸总量的27．80％。瘤背石磺必需氨基酸比例符合联合国棉农组织／世界卫生组织标准。瘤背石磺的限制性氨基酸是赖氨酸和色氨酸，4种鲜味氨基酸干样的总质量分数为25．33％。瘤背石磺不同部位的蛋白含量不同，表现为精卵巢蛋白〉腹足蛋白〉外套蛋白〉肝脏蛋白，且差异显著（P〈0．05）。矿物质元素含量丰富，钙、磷、铁、锌、铜含量较多，比例适宜，脂溶性维生素A、D、E含量丰富。营养成分分析结果表明，瘤背石磺具有较高的食用价值和保健作用。     

野生金乌贼成体肌肉的营养成分分析及评价

为丰富金乌贼(Sepia esculenta)的生化信息和充分了解其营养价值,作者采用生化方法测定了野生金乌贼成体肌肉的营养成分,并对其营养品质进行了分析与评价。结果显示:金乌贼肌肉中水分、粗蛋白、粗脂肪和粗灰分的含量占鲜样质量的比例分别为71.10%、22.02%、0.75%和2.17%。肌肉中主要含有17种氨基酸,氨基酸总量占干样质量的64.75%,其中必需氨基酸总量为24.44%,占氨基酸总量的37.75%,与非必需氨基酸总量的比值为75.15%,符合FAO/WHO的理想模式;干样中呈味氨基酸的总量为25.34%,占氨基酸总量的39.14%;必需氨基酸平均得分为102.86,组成相对均衡,必需氨基酸指数EAAI为85.43,可做为人体理想的蛋白质来源。在脂肪酸组成方面,饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)、多不饱和脂肪酸(PUFA)的含量分别占脂肪酸总量的33.46%、8.64%、49.83%,其中EPA和DHA共占PUFA的84.35%,脂肪质量较高。此外野生金乌贼肌肉中矿物元素种类及含量较为丰富。分析认为,金乌贼蛋白质含量高、必需氨基酸组成均衡、脂肪质量较好并富含矿物元素,具有较好的食用价值和保健作用。本研究评估了金乌贼的开发利用价值,同时为其配合饲料研发提供了重要参考。     

荣成近岸海域四种褐藻营养成分分析及评价

山东省荣成市近岸海域褐藻资源丰富,为系统了解鼠尾藻(Sargassum thunbergii)、海黍子(Saragassumkjellmaniamum)、铜藻(Sargassum horneri)和羊栖菜(Sargassum fusiforme)四种褐藻的营养价值,通过测定其一般营养成分(水分、粗蛋白、粗脂肪、灰分、碳水化合物),氨基酸组成、脂肪酸组成、重金属含量等,对其营养价值进行分析及评价。结果显示:四种海藻一般营养成分以碳水化合物为主,其次为灰分,蛋白质和脂肪。氨基酸种类齐全且人体必需氨基酸质量分数较高,鼠尾藻、海黍子、铜藻和羊栖菜的必需氨基酸占氨基酸总量的比例分别为32.83%、37.35%、30.82%和40.55%,接近FAO/WHO的理想模式;呈味氨基酸占氨基酸总量比例分别为56.38%、51.67%、49.78%和45.07%,使得具有较好的风味,可作为开发海藻调味料的原料;必需氨基酸指数(EAAI)分别为85、71.79、73.38和95.80;脂肪含量低,脂肪酸含量依次为饱和脂肪酸多不饱和脂肪酸单不饱和脂肪酸,四种褐藻n-3脂肪酸和n-6脂肪酸的总量分别占脂肪酸总量的27.54%、25.71%、28.68%和27.14%;铅、汞、无机砷和镉的含量均低于相关限量要求。研究表明:海黍子、鼠尾藻、铜藻和羊栖菜高蛋白、低脂肪,氨基酸组成完全,必需氨基酸质量分数较高,呈味氨基酸比例较高,多不饱和脂肪酸占脂肪酸含量比较高,是营养丰富、安全的海洋藻类资源。     

海南岛3种石磺肌肉组织营养成分分析

参照国家食品营养成分分析相关标准,结合液相色谱仪,元素分析仪,电感耦合等离子光谱仪等测定海南岛采集的瘤背石磺(Onchidium struma),紫色疣石磺(Peronia verruculata),平疣桑葚石磺(Platevindex mortoni)3种石磺肌肉组织中营养成分。结果表明:海南岛3种石磺均属于高蛋白质低脂肪的海产品,蛋白质含量达65.0%以上,其中以平疣桑葚石磺蛋白质含量最高;瘤背石磺肌肉组织多糖含量高达30.96%±1.48%,显著高于其他2种石磺;3种石磺肌肉组织中氨基酸组成全面,且以呈味氨基酸含量最高,均达5.60%以上;3种石磺肌肉组织均含有丰富的矿质元素,其中以钙和镁元素含量最高,含量达20~30 g/kg,同时钠和钾元素含量达3.0~6.5 g/kg。海南岛3种石磺均具有丰富的营养价值,其中以高蛋白高多糖低脂肪的瘤背石磺最具有开发前景。     

美洲黑石斑鱼含肉率及肌肉营养成分分析

利用常规肌肉营养测试方法,测定分析了美洲黑石斑鱼的含肉率及肌肉营养成分。测定结果显示,美洲黑石斑鱼含肉率平均值为(73.71±1.93)%,肌肉(鲜样)中粗蛋白、粗脂肪、水分和粗灰分含量分别为(19.09±1.34)%,(6.14±1.76)%,(71.86±1.58)%和(1.32±0.17)%;美洲黑石斑鱼肌肉中被测出的常见氨基酸(色氨酸未测定)有17种,其中包括7种必需氨基酸、2种半必需氨基酸和8种非必需氨基酸,其氨基酸含量占鲜体质量的百分比分别为(8.27±0.21)%,(1.84±0.08)%和(10.15±0.31)%,17种氨基酸总含量为(20.26±1.13)%(鲜样)。谷氨酸(Glu)含量占鲜体质量的百分比最高,为(3.27±0.16)%,其次是天冬氨酸(Asp)和赖氨酸(Lys),胱氨酸(Cys)含量占鲜体质量的百分比为最低,仅为(0.27±0.01)%。4种鲜味氨基酸含量占干样的(29.32±0.14)%。鲜样的美洲黑石斑鱼必需氨基酸总量占氨基酸总量的比值为40.82%,干样的为40.81%;鲜样的必需氨基酸总量与非必需氨基酸总量的比值为81.48%,干样的为81.43%,其构成符合FAO/WHO的标准。同时计算出的美洲黑石斑鱼肌肉蛋白质氨基酸评分(AAS)均大于1,化学评分(CS)均大于0.7,必需氨基酸指数(EAAI)达到91.18,高于多数海产经济鱼类,说明它能为人体提供大量必需氨基酸,且其组成接近人体的氨基酸需要量模式。美洲黑石斑鱼肌肉中主要含有16种脂肪酸,其中饱和脂肪酸(SFA)7种,含量占肌肉脂肪酸总量的(38.66±1.22)%;不饱和脂肪酸(UFA)9种,含量占肌肉脂肪酸总量的(61.36±0.98)%,其中单不饱和脂肪酸(MUFA)5种,多不饱和脂肪酸(PUFA)4种。多不饱和脂肪酸中的人和动物生长发育必需的脂肪酸EPA和DHA含量,分别占总脂肪酸的(9.02±0.59)%和(11.73±0.43)%。-ω3族与-ω6族PUFA总量的比值为5.30。分析表明,美洲黑石斑鱼肌肉含肉率高,含有较多的粗蛋白和粗脂肪,氨基酸总量及鲜味氨基酸含量均较高,是一种优质蛋白源;美洲黑石斑鱼肌肉富含PUFA,尤其是EPA和DHA含量丰富,并且∑n3/∑n6值较高,因而具有较高的食用营养价值和保健功效,是一种具有广阔市场前景的优良养殖品种。     

渤海银鲳肌肉生化成分分析与营养价值评价

研究采用现代生化分析方法,测定了渤海银鲳肌肉的营养成分,结果表明:肌肉含水量76.22%,蛋白质16.76%,脂肪5.03%,灰分1.31%,无氮浸出物0.68%;肌肉组织中的18种氨基酸中以谷氨酸含量最高,天冬氨酸次之,亮氨酸居于第三位;肌肉组织中的主要脂肪酸排列顺序如下:C18:1(n97)C16:0C22:6n3C16:1n7C18:0,饱和脂肪酸(SFA)占脂肪酸总量的23.32%～33.15%,单烯酸(MUFA)占22.49%～29.97%,多不饱和脂肪酸(PUFA)占13.11%～22.50%,EPA和DHA之和占7.18%～10.08%。根据1973年FAO/WHO推荐的必需氨基酸需要量模式对银鲳肌肉进行评价,氨基酸比值系数分为83,第一限制性氨基酸为亮氨酸。     

鲣鱼(Katsuwonus pelamis)肌肉蛋白在热处理过程中的营养变化及功能性评价

为研究鲣鱼在热处理过程中背部肌肉营养成分变化情况,测定鲣鱼背部肌肉的水分、灰分、蛋白质、氨基酸、脂肪、脂肪酸及矿物质元素等指标的含量,并对其进行了氨基酸评分。结果表明:蒸煮前后的鲣鱼背部肌肉蛋白质含量分别为24.56%、20.42%,脂肪含量分别为1.03%、2.37%,灰分含量分别为1.97%、0.74%,水分比重均达60%以上。生鲣鱼肌肉的必需氨基酸总量高达499.9mg/g,熟鲣鱼肌肉的必需氨基酸总量达到412.4mg/g,均不含限制性氨基酸,熟鲣鱼肌肉的必需氨基酸含量低于鸡蛋蛋白质的必需氨基酸模式,但高于FAO/WHO推荐的学龄前儿童体内的必需基酸模式;而生鲣鱼肌肉的必需氨基酸含量均超过了两个参考必需氨基酸需要量模式;生鲣鱼背部肌肉的DHA和EPA含量为29.9%,熟鲣鱼肌肉的含量更高,为32.3%;生、熟鲣鱼肌肉K元素含量最高,也含有丰富的微量元素,如Fe、Cu、Zn、Se等。因此,热处理前后的鲣鱼背部肌肉均为高蛋白、低脂肪、矿物质丰富,味道鲜美的理想食品。     

太平洋侧花海葵的营养成分分析

本文测定了太平洋侧花海葵中的蛋白质、脂肪和无机元素等营养成分,分析了太平洋侧花海葵中构成蛋白质的17种常见氨基酸和主要脂肪酸含量。结果表明,太平洋侧花海葵是一种高蛋白、低脂肪的海产品;必需氨基酸和鲜味氨基酸的含量较高,但必需氨基酸之间的比值不太符合人体的氨基酸平衡,宜与其他食物搭配食用。各类脂肪酸中,油酸(18∶1)含量最高,其次为C22∶2。无机元素丰富,尤其是Zn,含量可达254.4 mg/kg。     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone.     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics.     

INFORMATION FOR AUTHORS

<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,     

Estimation of Sediment Properties during Benthic Impact Experiments

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.