Influence of salt and herbal substance on the drying and reconstitution performance of Bombay duck, Harpodon nehereus

Effects of salt, chili and turmeric powder on the production of high quality dried fish products from Bombay duck (Harpodon nehereus) under open sun drying was investigated. Five different types of dried products (T1-T5) were produced and studied. Moisture content in T3 decreased more rapidly to below 16% within 28 hrs of drying compared to those treated with other treatments (temperature varies from 24.6°C to 34°C and relative humidity varies between  60% and 48%) . Drying process was very slow in control samples where it took 32 hrs for reaching the moisture level to 18.75%. Both turmeric and chili powders had strong repellency effect against insect infestation. Bombay duck treated with salt and herbal products were less infested by the blowfly whereas samples dried under control treatment were severely infested by blowfly

Rigor index, fillet yield and proximate composition of cultured striped catfish (Pangasianodon hypophthalmus) for its suitability in processing industries in Bangladesh

Rigor-index in market-size striped catfish (Pangasianodon hypophthalmus, locally called Thai-Pangas) was determined to assess fillet yield for production of value-added products. In whole fish, rigor started within 1 hr after death under both iced and room temperature conditions while rigor-index reached a maximum of 72.23% within 8 hr and 85.5% within 5 hr at room temperature and iced condition, respectively, which was fully relaxed after 22 hr under both storage conditions. Post-mortem muscle pH decreased to 6.8 after 2 hr, 6.2 after 8 hr and sharp increase to 6.9 after 9 hr. There was a positive correlation between rigor progress and pH shift in fish fillets. Hand filleting was done post-rigor and fillet yield experiment showed 50.4±2.1% fillet, 8.0±0.2% viscera, 8.0±1.3% skin and 32.0±3.2% carcass could be obtained from Thai-Pangas. Proximate composition analysis of four regions of Thai-Pangas viz., head region, middle region, tail region and viscera revealed moisture 78.36%, 81.14%, 81.45% and 57.33%; protein 15.83%, 15.97%, 16.14% and 17.20%; lipid 4.61%, 1.82%, 1.32% and 24.31% and ash 1.09%, 0.96%, 0.95% and 0.86%, respectively indicating suitability of Thai-Pangas for production of value-added products such as fish fillets

Quality Assessment of Traditionally Dried Marine Fish of Bangladesh

A study was conducted to assess organoleptic, biochemical and microbiological quality aspects of traditionally dried marine fish products of one of the largest fish drying zones of Bangladesh viz., Cox’s Bazar and Teknaf. It was found that eight species viz., Stromateus chinensis, S. cinereus, Riksha sp., Johinus argentatus, Trichiurus haumela, Harpodon neherus, Lutianus johnii and Penaeus sp. were commonly used as raw materials to produce traditional dried fish. Organoleptic characteristics in respect of colour, odour, texture, insect infestation and presence of broken pieces in the products indicated poor to moderately acceptable condition while water reconstitution rate was found to be slower in majority of the traditional sun dried products. Results of the proximate composition such as moisture, crude protein, lipid and ash content of these products ranged from 18.56% to 24.20%, 33.56% to 58.22%, 2.74% to 15.44% and 15.87% to 32.22% respectively. Total volatile base nitrogen (TVB-N) and peroxide value (PV) were 28.46 ± 0.5 to 42.88 ± 4.9 mg N/100g and 46.80 ± 1.9 to 82.70 ± 3.8 m.eq/kg oil respectively, both of which were higher than the recommended values for dried fish. Microbial load, on the other hand, ranged from 0.95 × 104 to 1.9 × 105 CFU/g indicating varying levels of viable bacteria in those products while no coliform bacteria were detected in these samples. These data provide valuable information on these highly relished dried fish for domestic consumers in order to choose them based on their quality aspects

High-Throughput Sequencing of the Expressed Torafugu (Takifugu rubripes) Antibody Sequences Distinguishes IgM and IgT Repertoires and Reveals Evidence of Convergent Evolution

B-cell antigen receptor (BCR) or antibody diversity arises from somatic recombination of immunoglobulin (Ig) gene segments and is concentrated within the Ig heavy (H) chain complementarity-determining region 3 (CDR-H3). We performed high-throughput sequencing of the expressed antibody heavy-chain repertoire from adult torafugu. We found that torafugu use between 70 and 82% of all possible V (variable), D (diversity), and J (joining) gene segment combinations and that they share a similar frequency distribution of these VDJ combinations. The CDR-H3 sequence repertoire observed in individuals is biased with the preferential use of a small number of VDJ, dominated by sequences containing inserted nucleotides. We uncovered the common CDR-H3 amino-acid (aa) sequences shared by individuals. Common CDR-H3 sequences feature highly convergent nucleic-acid recombination compared with private ones. Finally, we observed differences in repertoires between IgM and IgT, including the unequal usage frequencies of V gene segment and the biased number of nucleotide insertion/deletion at VDJ junction regions that leads to distinct distributions of CDR-H3 lengths

Aedes Larva Detection Using Ensemble Learning to Prevent Dengue Endemic

Dengue endemicity has become regular in recent times across the world. The numbers of cases and deaths have been alarmingly increasing over the years. In addition to this, there are no direct medications or vaccines to treat this viral infection. Thus, monitoring and controlling the carriers of this virus which are the Aedes mosquitoes become specially demanding to combat the endemicity, as killing all the mosquitoes regardless of their species would destroy ecosystems. The current approach requires collecting a larva sample from the hatching sites and, then, an expert entomologist manually examining it using a microscope in the laboratory to identify the Aedes vector. This is time-consuming, labor-intensive, subjective, and impractical. Several automated Aedes larvae detection systems have been proposed previously, but failed to achieve sufficient accuracy and reliability. We propose an automated system utilizing ensemble learning, which detects Aedes larvae effectively from a low-magnification image with an accuracy of over 99%. The proposed system outperformed all the previous methods with respect to accuracy. The practical usability of the system is also demonstrated

Studies on the quality attributes and safety aspect of semi-fermented fish product

955-960Semi-fermented fish product was organoleptically of satisfactory quality and it was organoleptically acceptable for a long time. Proximate composition of the semi-fermented fish product was comparable with other processed fish and fishery products. Proximate composition data were moisture 36.63%, protein 33.74%, lipid 18.54% and ash 11.83%. Total Volatile Base Nitrogen (TVB-N) of this semi-fermented product was 3.08 mg/100 g. Bacterial load of semi-fermented fish product was 1.18 × 106 CFU/g. To confirm the safety aspect of the semi-fermented fish product of this research study the exact quality of metal and elements particularly the heavy metal quantity was determined. Result of heavy metal concentrations in semi-fermented fish product “Sheedal Shutki or Chapa Shutki” was Arsenic 0.019 <span style="font-size:9.0pt;mso-bidi-font-family: Symbol">µg/g, Cadmium 0.075 µg/g which were within the acceptable level for human consumption. </span