Quality and Processing Possibilities of Western Baltic Sea Spring Spawning Herring

Abstract

Until 1990 the western Baltic Sea spring herring has been extensively used as raw material for the processing industry of the former German Democratic Republic. Today North Sea herring and other Atlantic herring stocks are preferred and utilization of the Baltic Sea herring stock, which has been caught between January and May around the Island of Rügen and in the Greifswalder Bodden, has dropped down dramatically. The reduction in exploitation of this resource is connected to enhanced quality specification required by German herring processing companies after reunion of both states.

In this study the quality of Baltic Sea spring herring from ICES subdivisions 22 and 24 was assessed and following conclusions were obtained:

• Processing possibilities of Baltic Sea spring herring are limited due to low fat content (5-8%), a slight dry and short fiber texture and a less typical flavour and taste.

• Off-flavour and taste (tainting) which has been often observed until mid nineties disappeared within the last years.

• Infestation rates and abundance of nematodes (Anisakisspp.) are comparable to North Sea herring stocks.

• Contamination levels of organic and inorganic pollutants are far below legal limits.

Only gill net fishery and trap fishing are able to guarantee a continuous supply of desired size classes 2 and 3. Trial with pair trawl fishing did not show promising results.

Due to reorganization and reduction of local fishery activities during the past ten years, an increase of the annual landing capacity of more than 10,000 t is questionable in future.     

高校邓小平理论“三进”现状的调查分析与对策

高校邓小平理论“三进”存在的问题是：外热内冷,学习积极性不高;理论与实践相脱节,理论不能指导实际;方法不多,教法单一;存在着片面认识。采取的对策是：要进一步加强对“三进”工作的领导力度;要建设一支高素质的教师队伍;要充分发挥实践教学的作用;把“三进”工作融入校园文化建设之中。     

Lipid dynamics in anadromous Arctic charr, Salvelinus alpinus (L.): seasonal variations in lipid storage depots and lipid class composition

Changes in lipid class composition of tissues of anadromous Arctic charr, Salvelinus alpinus, were studied in relation to seasonal patterns of lipid deposition and lipid mobilisation. Charr of a north Norwegian population were collected in late May when fish were migrating towards the sea, and in mid-July when the fish re-entered fresh water. Some maturing fish captured in mid-July were held in captivity until late September to assess lipid dynamics associated with maturation. The carcass (head, fins, skeleton and skin) accounted for approx. 50% of the total body lipid content when the fish re-entered fresh water from the sea. Triacylglycerols (TAG) comprised 75-80% of the carcass lipid in ascending charr, confirming that the carcass is a major lipid depot. The skeletal muscle also represented a major lipid store: muscle of ascending charr contained 35-40% of the body lipids, with TAG being dominant (approx. 75% of muscle lipid). The gut (gastrointestinal tract and visceral lipid) and liver of ascending charr each held only 4-5%; of the body lipid, TAG being the dominant lipid class in both of these depots (Gut TAG: 60-65%; Liver TAG: 50-55%). Body lipid decreased 30-40% during maturation: lipids were depleted from all depots, but mobilisation of from the carcass and muscle was quantitatively the most important. In mature females, the ovaries held almost 25% of the body lipid, with the proportion of TAG exceeding that of polar lipids (PL)(TAG: 62%; PL 12.4%). In the mature males, the testes accounted for less than 3% of the total lipids. TAG tended to dominate the testis lipids (TAG: 29.5%), but there were also quite high proportions of free fatty acids, cholesterol and polar lipids (FFA: 23.5%; C: 15%; PL 9.7%). Females lost approx. 80% of their body lipid during spawning and overwintering, the majority of this being TAG. Males also lost large amounts of TAG during the winter, but in contrast to the females lipid depletion amounted to only 50-55% of that present at the time of ascent into fresh water.     

Invertebrate uptake of lipids in the vicinity of Atlantic salmon (Salmo salar) aquaculture sites in British Columbia

Samples of invertebrates, primary producers, seawater and cores were taken surrounding several aquaculture sites in coastal British Columbia, Canada. Analysis of dissolved organic carbon (DOC) showed a significant decrease (P = 0.027) over 1 km and an overall average of 290 ± 40 μM at 1 m depth. At 10 m, the decrease was not significant and DOC averaged 81 ± 3 μM. The essential fatty acid 22:6ω3 (docosahexaenoic acid, DHA) was significantly lower nearer to the farm sites for all mollusc taxa as well as for mussels alone (P < 0.01). However, mussel wet weight as well as the zooplankton fatty acid marker (ZFA; Σ 20:1ω9, 22:1ω11, 22:1ω9) and 20:1ω9 individually, decreased significantly with distance from the farms (P < 0.03). Principal components analysis showed a similar trend with DHA being higher in molluscs further from the farm. Mussels had significantly higher amounts of DHA compared with other molluscs indicating their potential in multi‐trophic, co‐culturing systems. Bacterial fatty acid markers increased in molluscs with distance from the farms; however, 18:1ω7, which is representative of methane‐oxidizing bacteria, remained higher closer to the farm. In addition, DHA proportions in mussels showed a significant breakpoint at 339 m from the farm suggesting co‐cultured mussels would benefit from placement further than 339 m from farms where DHA would be optimized.     

Fatty acids, bioactive lipids and radical scavenging activity of Celastrus paniculatus Willd. seed oil

In the present contribution lipid composition and characteristics of Indian Celastrus paniculatus seed oil were determined. C. paniculatus seeds are a rich source of oil (46%). The amounts of neutral lipids in the oil were the highest, followed by glycolipids and phospholipids. Oleic followed by palmitic and linoleic were the major fatty acids in C. paniculatus seed oil and its lipid classes. C. paniculatus seed oil being characterized by a relatively high amount of phytosterols, wherein the sterol marker was β-sitosterol followed by campesterol and stigmasterol. γ-Tocopherol was the major tocopherol isomer while the rest being α-tocopherol. When C. paniculatus oil and extra virgin olive oil were compared upon their radical scavenging activity (RSA) toward the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical C. paniculatus oil exhibited stronger RSA. In consideration of potential utilization, detailed knowledge on the composition of C. paniculatus oil is of major importance. The diversity of applications to which C. paniculatus oil can be put gives this plant great industrial importance.     

兰州市高校木本植物群落研究

利用天然群落的样带调查法对兰州市高等院校校园绿化群落进行调查,统计树种的重要值,分析群落垂直结构、优势种胸径径级结构,并对绿化存在的问题提出相应的改善措施。       

氮肥种类对蔬菜产量和品质影响的研究

尿素、碳铵和氯铵对蔬菜产量和品质的影响的田间试验结果表明,大白菜在等氮量情况下,对尿素,碳铵和氯铵的肥效无显著差异,盆栽试验结果也表明,尿素与碳铵肥效相当,唯氯铵肥效因蔬菜种类而异,氯铵有明显降低蔬菜硝酸盐含量的效果,氯铵与尿素相比,约降低硝酸盐50%,在中等氮素水平下,尿素、碳铵和氯铵处理,蔬菜硝酸盐平均含量分别为659,633和440 ppm,除氯铵处理在允许范围内外,尿素和碳铵处理均超过标准。     

食品的昆虫螨霉菌主要种类及为害研究

1983—1986年调查了重庆地区51种食品发生昆虫、霉种类。初步鉴定属于害虫的28种,天敌昆虫3种,螨14种,霉菌15种。研究了主要种类的为害和习性,并讨论了有关防治措施。     

托木尔峰自然保护区朽木生地衣物种分布特征

为进一步确定影响朽木生地衣物种分布的环境因素,在托木尔峰自然保护区的北坡海拔1 950~2 750 m地带选择18个样地对朽木生地衣物种多样性及其物种分布格局进行了研究。结果表明,地衣种类的多样性和朽木径阶、海拔和腐蚀阶段之间有显著的相关性。地衣种类与朽木径阶的相关性系数R~2为0.624 7,50~75 cm径阶的朽木上地衣的多样性最大。地衣群落的结构和物种组成随着海拔高度发生变化,其相关性系数R2为0.776 8,一般在海拔1 950~2 150 m的地带朽木上地衣群落的物种丰富度最高。不同腐蚀阶段的朽木上地衣种类和丰富度间存在显著性差异。     

樟子松人工幼中龄林不同生长级林木叶面积分布

根据东北东部山地3个地点7块样地的调查结果,分析了樟子松人工幼中龄林中不同生长级林木的叶面积分布状况.结果表明:①不同生长级林木之间叶面积有明显差异,以上层木叶面积最大,中层木次之,下层木最小,其中上层木与中层木之间的叶面积差异相对较小;②叶面积主要集中在树冠的中、上部,下部比例很小:③构成叶面积主要部分的都是1 a和...