Development and Biochemical Composition Assessment of Fish Powders from Bangladeshi Indigenous Fish Species and Shelf-Life Characteristics Evaluation During 90 Days of Room Temperature (27°C - 30°C) Storage

In Bangladesh, Fish is a major source of daily protein intake of millions of people but most of the fishes are consumed here as fresh fish which is highly susceptible to damage during transportation and marketing. Therefore, an innovative approach was undertaken to process the fish to avoid damage and extend shelf-life while preserving the nutritional qualities to facilitate the more efficient use of fish as a source of protein and other essential nutrients. This study was conducted to develop some dried protein-enriched fish powders from some commonly consumed fish species in Bangladesh and the nutritional, sensorial, and safety qualities were assessed. Five indigenous abundant fish species including small indigenous fish (SIS) and carp fishes namely Awaous grammepomus, Channa punctata, Puntius puntio, Hypophthalmichthys molitrix and Labeo rohita were used for the preparation of dried protein-enriched fish powders. Biochemical, trace elements, sensorial, total viable count (TVC), pH, peroxide value, and moisture reconstitution during 90 days storage period were performed by standard analytical methods. The moisture, protein, fat, ash, carbohydrate (including fiber), and energy contents were ranged from (6.84% to 8.85%), (70.80% to 75.80%), (5.85% to 8.04%), (7.66% to 9.19%), (3.14% to 6.01%) and (367.50% to 379.61% kcal)/100g respectively. Highest content of protein was found in A. grammepomus (75.80%) samples and the lowest in H. molitrix (70.80%) samples. Maximum calcium content was found in sample L. rohita (2.54 g/kg) and minimum in C. punctate as (2.43 g/kg). Maximum iron content was found in H. molitrix (0.15 g/kg) and minimum in A. grammepomus. As for the phosphorous content the L. rohita samples contained the highest (1.4 g/kg) and the lowest in C. punctate (0.73 g/kg) samples. The pH, peroxide value (mEq of O2/kg of fat), and moisture reconstitution (g/100g) during 90 days were ranged from (5.30 to 8.17), (8.60 to 16.77), and (6.84 to 13.83) respectively. Microbial loads over the 90 days period were in acceptable range at the end of 90 days storage period. On the basis of biochemical qualities, sensorial and microbial attributes our findings suggest that the dried fish powders are enriched with macro and micro-nutrients especially proteins and could safely be used at least up to 3 months for food applications.

Mulching type-induced soil moisture and temperature regimes and water use efficiency of soybean under rain-fed condition in central Japan

Soybean(Glycine max)is a high water-demand crop and grown under moderate temperature in Japan.To protect the crop from hot summer and to utilize rainfall for its cultivation,selection of appropriate mulching material(s)is crucial.For optimum production of the crop,soil moisture and temperature regimes as well as water use efficiency(WUE)of the crop were investigated under straw,grass,paper,plastic and bare soil(control)mulching under rain-fed condition at Gifu university farm in Japan.The mulching treatments,compared to the control,lowered soil temperature by 2°C at 5 cm depth and 0.5°C at 15 and 25 cm depths.The plastic and straw mulching stored the highest quantity of soil moisture at 5 and 15 cm depths;the bare soil stored the lowest quantity.At 25 cm depth,soil-moisture content was the highest under paper mulch but invariable under the other mulches.Plastic mulching reduced evaporation rate from the soil surface and,consequently,the reduced soil-water consumption(SWC)from the root zone augmented WUE of soybean.The paper mulching,by conserving soil-moisture and reducing soil temperature,provided better crop growth attributes,while the plastic mulching improved WUE of green soybean.Therefore,the plastic mulch performed best in reducing soil-water consumption and increasing WUE,while the paper mulch was good for soil-moisture conservation and temperature modification that increased soybean yield.