Detection of Rossby waves in multi-parameters in multi-mission satellite observations and HYCOM simulations in the Indian Ocean

Rossby waves are difficult to detect with in situ methods. However, as we show in this paper, they can be clearly identified in multi-parameters in multi-mission satellite observations of sea surface height (SSH), sea surface temperature (SST) and ocean color observations of chlorophyll-a (chl-a), as well as 1/12° global HYbrid Coordinate Ocean Model (HYCOM) simulations of SSH, SST and sea surface salinity (SSS) in the Indian Ocean. While the surface structure of Rossby waves can be elucidated from comparisons of the signal in different sea surface parameters, models are needed to gain direct information about how these waves affect the ocean at depth. The first three baroclinic modes of the Rossby waves are inferred from the Fast Fourier Transform (FFT), and two-dimensional Radon Transform (2D RT). At many latitudes the first and second baroclinic mode Rossby wave phase speeds from satellite observations and model parameters are identified. Wavelet transforms of these multi-parameters from satellite observations and model simulations help to discriminate between the annual and semi-annual signal of these Rossby waves. This comprehensive study reveals that the surface signature of Rossby waves in SSS anomalies is likely to be between 0.05 and 0.3 psu in the South Indian Ocean.     

Effect of Film-Forming Gums in the Preservation of Salted and Dried Indian Mackerel (Rastrelliger kanagurta Cuvier)

Curing preservation of fish is the most popular method in the developing countries and India is no exception. Different film-forming gums, namely sodium alginate, tamarind kernel powder, guar gum and agar agar were tried to find their effect in preservation of salted and dried mackerel and in extending the shelf-life of these products. Various biochemical, microbiological and organoleptic parameters were recorded during the storage period. The treatment of salted dried fish with gum solutions and subsequent formation of film upon drying was found to be the best in preserving the quality of salted fish. The effect of film forming gums on the shelf-life of the products was found to be highly significant ( P< 0·05) as compared to the control.     

Investigating the Combined Effect of Natural and Metal Salt Mordants on Coloring Potential of Indian Rhubarb (Rheum emodi) Natural Dye

Synthetic dyes produce wide range of shades, but some of them especially azo dyes have been recently discovered to cause severe human health and environmental problems. This has motivated research activities in the exploitation of dyes from natural products for the coloration of different textile materials. In the present investigation, Indian rhubarb (Rheum emodi) was used as a source of natural dye for the development of deep and bright shades on premordanted woollen yarn samples. Dyeing experiments were carried on wool samples pretreated with different combinations of natural and chemical mordants such as 2.5% myrobalan + 10% alum, 2.5% myrobalan + 2% iron, and 2.5% myrobalan + 0.5% tin. The light, wash, and rub fastness properties of dyed woollen yarn samples were evaluated along with the determination of lightness (L*), chroma (c*), hue angle (h°), and strength (K/S) values using 8% concentration of Indian rhubarb dye.     

微生物对低钠干腌马鲛鱼风味的影响

为明确微生物对低钠干腌制马鲛鱼风味的影响,测定抑菌剂（柠檬烯和肉桂醛）处理对低钠干腌制马鲛鱼的挥发性风味物质及其前体物质种类和含量的影响。结果显示,2种抑菌剂均可以抑制干腌马鲛鱼中风味物质的产生,分别使得风味物质从36种降到24种和20种。关键香气物质均从9种降到8种（辛醛、壬醛、庚醇、顺-4-癸醛、癸醛、己醛、1-辛烯-3-醇和6-甲基-5-庚烯-2-酮）,减少了3-甲基丁醛。抑菌剂同样抑制了风味前体脂肪酸和氨基酸的产生,提示微生物活动对低钠干腌马鲛鱼风味的产生影响显著。本研究结果为干腌马鲛鱼加工工艺提供了技术支持。     

介质阻挡放电低温等离子体在鲐鱼杀菌及组胺含量控制中的作用

为探究介质阻挡放电低温等离子体(atmospheric cold plasma,ACP)处理鲐鱼的杀菌效果以及在控制组胺含量中的作用,分别采用ACP直接处理和间接处理两种方式,分析鲐鱼菌落总数的变化,并通过响应面法中心组合设计优化了ACP杀菌的最佳处理电压和时间;在此基础上,探索ACP对鲐鱼贮藏过程中组胺含量以及与组胺产生有关的假单胞菌、肠杆菌、弧菌的影响。结果表明:直接处理对鲐鱼的杀菌效果更优,菌落总数降低率比间接处理高35.88%;最佳处理条件为处理电压59.9 k V、处理时间71.5 s;在优化条件下,鲐鱼菌落总数为1.83(lg(CFU/g)),与预测值1.86(lg(CFU/g))相差不大,所建模型与实际拟合较好;经ACP处理后的鲐鱼在贮藏期(14 d)内,假单胞菌、肠杆菌、弧菌的生长速率明显低于对照组;贮藏第8天时,假单胞菌、肠杆菌、弧菌的菌落数比对照组分别降低25.89%、46.23%和45.23%;组胺含量在贮藏期内增长较慢,第14天时含量为72.34 mg/100 g,低于国标限量。     

鲐鱼低温冻藏过程中脂肪氧化特性

鲐鱼组氨酸含量较高,在低温贮藏中品质易发生劣变,影响其食用安全性.以-18℃冻藏的鲐鱼为研究对象,在贮藏0、10、20、40、60、80、100 d后分别取样,测定鲐鱼风味、过氧化值、酸价、硫代巴比妥酸反应物(thiobarbituric acid reactive substances,TBARs)值和脂肪酸成分的变...     

不同贮藏温度下鲐鱼生物胺变化的研究

为探究不同温度和预处理对鲐鱼生物胺含量变化的影响,用高效液相色谱法分析了整鱼和去内脏鱼在不同贮藏温度下8种生物胺以及总生物胺含量的变化,结果发现,鲐鱼中主要的生物胺为组胺、腐胺、尸胺、酪胺。随着温度的升高,鲐鱼中总生物胺含量的增加迅速变快。在0、4、10、15、20、25和30 ℃贮藏1 d后,整鱼中总生物胺的积累量分别为40.34、93.44、107.95、73.39、119.99、4649.90、6446.43 mg/kg。在0、4、10、15、20、25和30 ℃贮藏条件下,整鱼中组胺的含量超过国家规定的高组胺鱼类安全限量(400 mg/kg)的时间分别为12、5、4 d和48、36、15、14~16 h,-18 ℃贮藏6个月,组胺积累量仅为13.45 mg/kg。另外,去内脏能减少生物胺的生成,在-18、0、4、10、15、20、25和30 ℃贮藏条件下,去内脏后总生物胺最终积累量减少程度分别为14.22%、39.79%、13.83%、29.06%、22.60%、13.56%、26.13%、21.26%。因此,低温冷冻和去内脏处理能够有效控制鲐鱼中生物胺的生成,防止腐败。本研究为有效控制鲐鱼生物胺的产生提供了参考依据。