Improved quality and shelf life of farmed trout (Oncorhynchus mykiss) by whole processing in a combined ozonised flow ice refrigeration system

A combined refrigeration system consisting of ozone and flow ice was evaluated for the sacrifice, cooling and chilled storage of continental trout. The batch processed in ozonised flow ice exhibited significant ( P  < 0.05) reductions (0.97 and 1.51 log CFU cm⁻²) in skin aerobes and psychrotrophs on days 6 and 9, respectively, and significant ( P  < 0.05) reductions (0.94 log CFU g⁻¹ and 0.96 log CFU g⁻¹) in aerobes, and proteolytic bacteria in muscle on day 13. A significant ( P  < 0.05) inhibition of TMA-N formation after 9 days was also observed, with an average reduction of 28.4% along the storage period, Slight reductions in autolytic breakdown mechanisms were also observed in the ozonised batch, a maximum reduction of 14.82% being reached on day 13. The microbial and biochemical changes were well correlated with the sensory evaluation, which revealed relevant differences between the batches on day 13 and a shelf life extension of the ozonised batch up to day 16.     

Efficacy of the plant phototoxinα-terthienyl againstAedes intrudens and effects on nontarget organisms

The botanical phototoxin, -terthienyl (-T) was spray applied to natural or artificial pools containing mosquito (Aedes intrudens) larvae and nontarget invertebrates (caddisfly, damselfly, midge, shrimp,Daphnia, snail) and one vertebrate (trout) at concentrations varying from 0.01 to 1 kg/hectare, under field and laboratory conditions. All field-treated nontarget invertebrates survived -T treatment better thanA. intrudens which can be controlled at doses as low as 0.01 kg/hectare within one week. Under laboratory conditions, snails and trout survived -T and UV treatments up to 10 kg/ hectare. These results compare favorably with organophosphates and pyrethroid insecticides currently used for mosquito control. The results confirm that -T is a highly effective larvicide with acceptable nontarget effects.     

光栅产生带状谱的彩虹消色全息术

本文提出利用光栅产生类似多狭缝形式的带状谱获得消色像的全息记录方法,讨论了获得消色像的条件,并给出了实验结果。     

Comparison of six different sewage treatment processes—Reduction of estrogenic substances and effects on gene expression in exposed male fish

Treated sewage effluents often contain a mixture of estrogenic compounds in low concentrations. The total combined activity of these, however, may be sufficiently high to affect the reproduction of aquatic vertebrates. The introduction of advanced treatment technologies has been suggested as a way to remove micro-contaminants, including estrogenic substances. In this study, one municipal influent was treated with six different processes in parallel on a semi-large scale in order to assess their potential to reduce substances that could contribute to estrogenic effects in male fish. The effluent from a conventional, activated sludge treatment line was compared to a similarly treated effluent with a final sand-filtering step. The addition of ozonation (15 g O₃/m³), a moving bed biofilm reactor (MBBR) or both in combination was also evaluated. There was also a separate treatment line that was based on a membrane bioreactor. A small battery of hepatic estrogen-responsive genes was measured in the exposed fish using quantitative PCR. Concentrations of steroid estrogens and estrogenic phenols in the effluents were measured by GC-ECNI-MS. The ozonated effluents were the only tested effluents for which all measured biological effects in exposed fish were removed. Chemical data suggested that the MBBR technology was equally effective in removing the analyzed estrogens; however, elevated expression of estrogen-responsive genes suggested that some estrogenic substances were still present in the effluent. The membrane bioreactor removed most of the measured estrogens and it reduced the induction of the estrogen-responsive genes. However, fish exposed to this effluent had significantly enlarged livers. Given that the same influent was treated in parallel with a broad set of technologies and that the chemical analyses were combined with an in vivo assessment of estrogenic responses, this study provides valuable input into the assessment of advanced treatment processes for removing estrogenic substances.     

点阵合成体视动感全息图

首先获取三维物体不同视角的透视图,并对这些视图上的不同单元的光强信息用计算机分别收集、编码,得到一组编码片,依次在同一张全息片的不同点区域上记录编码片的信息.当普通灯光照明全息片时,双眼能同时分别接收到反映物体两个侧面的清晰再现像,构成体视像,而且像会随着人眼的移动而产生动感效应.本方法的优点是利用计算机对信息处理的精确性,再结合全息记录、再现的准确性,制作了一张点阵合成动感全息图样品,能看见清晰立体再现像,观察方便,人眼移动时再现像的动态效果逼真.     

Effect of rainbow trout (Oncorhynchus mykiss) plasma protein on the gelation of Alaska pollock (Theragra chalcogramma) Surimi

ABSTRACT:  The effect of rainbow trout plasma protein (RPP) on the gelation of Alaska pollock surimi was determined to evaluate the possibility of its commercialization as a new protein additive. For modori gel, the breaking force, deformation, whiteness, and water holding capacity increased as the addition amount of RPP (0 to 0.75 mg/g) increased, and decreased at higher concentration of RPP (0.75 to 1.50 mg/g) ( P < 0.05). Protein solubility of modori gel in the mixture of SDS, urea, and β-mercaptoethanol decreased as the addition amount of RPP increased up to 0.75 mg/g, and increased at higher concentration of RPP (0.75 to 1.50 mg/g) ( P < 0.05). The contents of trichloroacetic acid-soluble peptide decreased as the addition amount of RPP (0 to 1.50 mg/g) increased ( P < 0.05). Based on the result of sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE), most myosin heavy chain of surimi was not degraded when RPP was added. Thus, RPP was supposed to act as a protease inhibitor in the gelation of Alaska pollock surimi. An RPP of 0.75 mg/g was the optimal concentration to prevent the gel weakening of Alaska pollock surimi. Compounds with molecular weights less than 10 kDa in RPP had no significant effect on the gelation of Alaska pollock surimi based on the result of the dialyzed RPP.     

低场核磁结合电子鼻判定复合保鲜剂对冷藏虹鳟鱼片品质变化的影响

以质构、pH值、硫代巴比妥酸(TBA)值、挥发性盐基氮(TVB-N)值及菌落总数为评价指标,同时采用低场核磁共振(LF-NMR)及电子鼻技术对鱼片贮藏期间的水分和挥发性成分变化进行检测,研究复合保鲜剂(壳聚糖、茶多酚及柠檬汁)对虹鳟鱼片贮藏期间品质的影响。结果表明,复合保鲜剂组能较好地维持鱼片质构特性,同时可延缓鱼片TBA值、TVB-N值及菌落总数的增加。低场核磁测得两组鱼片贮藏期间T21幅值逐渐降低,在贮藏后期(12~14d),保鲜剂组鱼片自由水比例显著低于对照组(P0.05),且两组鱼片自由水比例与初期比较均增加。电子鼻PCA分析及LDA分析均可较好地区分贮藏期间鱼片的品质变化,LA分析发现引起鱼片新鲜度变化的主要成分为氮氧化合物、无机硫化物、芳香成分物质和乙醇等,而PCA分析结果表明对照组鱼片第6天开始发生腐败变质,保鲜剂组鱼片第10天开始趋于腐败。综上表明,低场核磁及电子鼻检测结果与理化指标结果具有一致性。     

茶多酚-壳聚糖复合液对虹鳟鱼肉贮藏品质和菌群结构的影响

针对虹鳟鱼在贮藏过程中易受到微生物的污染而发生腐败变质的问题,将3 g/L茶多酚和10 g/L壳聚糖混合制成复配保鲜剂,浸泡涂膜覆盖于虹鳟鱼表面。以感官评价、挥发性盐基氮含量、菌落总数及菌群结构等为指标,研究保鲜剂对4℃贮藏虹鳟鱼肉贮藏品质变化的影响。结果表明:茶多酚和壳聚糖单独使用或复合使用均能延缓腐败的发生;复配保鲜剂能将4℃贮藏虹鳟鱼的货架期从8 d延长至13 d,效果优于单独使用;未经处理的新鲜虹鳟鱼片菌群由16个菌属组成,腐败末期则以假单胞菌属为优势菌属,而复合保鲜剂涂膜会明显抑制假单胞菌属的生长,进而减缓鱼肉品质劣变。综上,茶多酚和壳聚糖的复配保鲜剂有助于通过抑制优势腐败菌的生长延缓4℃贮藏条件下虹鳟鱼的腐败变质。     

Visual perception of Fourier rainbow holographic display

The rainbow hologram provides views of reconstruction with rainbow color within a large viewing zone. In our recent paper, a Fourier rainbow holographic display using diffraction grating and a white‐light LED source was introduced. In this technique, the rainbow effect is realized by the dispersion of white‐light source on diffraction grating, while the slit is implemented numerically by reducing the demands of the space‐bandwidth product of the display. This paper presents a novel analysis on the visual perception of the Fourier rainbow holographic display using Wigner distribution. The view‐dependent appearance of the image, including multispectral field of view and viewing zone, is investigated considering the observer and the display parameters. The resolution of the holographic view is also investigated. For this, a new quantitative assessment for image blur is introduced using Wigner distribution analysis. The analysis is supported with numerical simulations and experimentally captured optical reconstructions for the holograms of the computer model and real object generated with different slit size, reconstruction distance, and different observation conditions.