Nutritional value of some small indigenous fish species (SIS) of Bangladesh

Twenty three small indigenous fish species (SIS) in the size range of 3-18 cm were analyzed for proximate composition and minerals (Ca and P) content to evaluate their nutritive value. The moisture content of different species ranged between 71.00 and 81.94%. In general, small sized fishes showed higher moisture content. The muscle protein content among the species varied widely (16.16-22.28%). In general, the muscle protein content of fishes showed higher value than the whole carcass protein content. The carcass lipid content varied between 1.87 and 9.55% and showed an inverse relationship with the moisture content. The gross energy content ranged from 19.51-27.30 KJ/g on dry matter basis. In the present study, the calcium and phosphorus contents ranged between 0.85-3.20% and 1.01-3.29% respectively. The calcium and phosphorus ratio (Ca/P) varied between 0.44 and 2.00. From the nutritional point of view, it shows that the SIS are good source of protein and minerals especially calcium and phosphoru

Effect of different feeds on growth, survival and production of African catfish (Clarias gariepinus Burchell)

An experiment was conducted to study the effect of different feeds on growth survival and production of African catfish (C. gariepinus) in six cemented tanks (3m² each) over a period of 120 days. Three different feeds namely Feed A (Saudi-Bangla fish feed, 33.43% protein), Feed B (formulated feed, 40.12% protein) and Feed C (chicken raw intestine, 59.58% protein) were applied to treatments I, II and III respectively. Each of the tanks was stocked with 24 fry with mean initial body weight of 2.56±0.06 g. Feeds were supplied to the fish ad-libitum daily in two instalments. Significantly highest weight gain was obtained in treatment III, however, survival rate was low compared to other treatments. The feed conversion ratio (FCR) values ranged from 2.52-6.4. Survival rate of fish varied between 83 and 96%. Treatment II yielded the highest (5000 kg/ha/120 days) production with the highest survival rate of fish. On the basis of survival rate and production, it is suggested that the formulated feed (Feed B) is suitable for the culture of C. gariepinus in cemented tanks

Identification and sensory evaluation of flavour enhancers in Japanese traditional dried herring (Clupea pallasii) fillet

Flavour-enhancing components of dried herring fillet (migaki-nishin in Japanese) were isolated and evaluated for their effects on sensory perception. Sensory evaluation revealed that addition of dried herring fillet water-soluble extracts to Japanese noodle soup significantly (P < 0.05) enhanced the soup flavour characters such as thickness, mouthfulness and continuity. The extracts were fractionated by dialysis and chromatography. Fractions containing flavour enhancers were isolated by sensory perception. Results from instrumental analyses showed that the kokumi flavour enhancers in dried herring fillet were creatine and creatinine

Mechanism involved in the formation of characteristic taste and flavor during the production of dried herring (Clupea pallasii) fillet

The objective of this study was to identify the mechanisms responsible for the characteristic taste and flavor of dried herring fillet (DHF, migaki-nishin in Japanese). Dialyzed water-soluble fractions (DWSF) obtained from the herring fillet dried for 4 days were mixed with fatty acids and the reaction products were evaluated for their effects on sensory perception. Further, to clarify the mechanisms of in situ chemical changes in DHF lipid, ESI-MS analysis was done using phosphatidylcholine probe. Sensory evaluation revealed that addition of the reaction products of DWSF with docosahexaenoic acid to Japanese noodle soup significantly (P < 0.05) enhanced the soup flavor characters such as thickness, mouthfulness, and continuity, compared to the reaction products of DWSF with linoleic acid or capric acid. ESI-MS analyses showed that lyso-derivatives were the most abundant compounds in the lipid fraction of DHF. A small amount of lipid oxidation products and their reaction products were also observed in DHF. This study demonstrated that during the drying period, partial hydrolysis of lipids released free fatty acids. These free fatty acids or their oxidation products might react with amino acid related compounds to generate the characteristic taste and flavor of DHF

Glycosylseramides obtained from the starfish Asterias amurensis Lütken

Complex lipids in the starfish Asterias amurensis were characterized and the influence of sphingoid bases on human colon carcinoma Caco-2 cells was also investigated. Lipid content of gonad and viscera were 3.3% and 6.8%, respectively, in wet basis. The main lipid class in gonad was ceramide monohexoside (CMH) while triglyceride (TG) was predominant in the viscera. The most abundant fatty acid in the polar lipid was eicosapentaenoic acid (EPA, C20:5n-3), with the gonad and viscera samples having the highest proportion of 41.5% and 32.7%, respectively, of total fatty acids. Starfish internal organ contained enormous amount (0.7% in wet base) of glycosylceramide. Sphingoid bases of the glycosylceramide were mainly consisted of d22:2, d22:1 and d18:3. This sphingoid base exerted an apoptotic activity on Caco-2 cells. Thus, starfish could be used as a potential source of precious and useful complex lipids

Changes in Physicochemical, Microbiological, and Sensory Properties of Sun-Dried Mystus vittatus During Storage at Ambient Temperature

The objective of this study was to investigate the changes in physicochemical, microbiological, and sensory properties of sun-dried Mystus vittatus during storage at ambient temperature. The fish was dried under sun exposure on bamboo mats for 5&ndash;6 days until the moisture content reduced to approximately 10&ndash;15%. The dried fish was then packed into airtight polyethylene bags and stored at ambient temperature (24 to 29 &deg;C) for 90 days. The physical and sensory properties revealed that the dried fish was acceptable for human consumption for up to 60 days. The pH value slightly decreased from 6.42 to 5.95 during the storage period. The moisture content increased significantly (p &lt; 0.05), while no significant difference was observed for the protein, lipid, and ash contents (on a dry matter basis) with the increase in the storage time. The peroxide value, acid value, and conjugated dienes of the lipids increased significantly during the storage period. The microbial load also increased with the increase in the storage period. The results of this study suggest that the product was slightly oxidized during the storage period and could be stored for up to two months

Biochemical, Microbiological, and Sensory Properties of Dried Silver Carp (Hypophthalmichthys molitrix) Influenced by Various Drying Methods

An experiment was performed to evaluate the effects of different drying methods with different pre-treatments on the physico-chemical, microbiological, and sensory properties of the silver carp, Hypophthalmichthys molitrix. In order to achieve this objective, the collected fresh fish were dried using traditional (without any pre-treatment), improved (fish soaked in a 5% salt solution for 10 min and then treated with chili powder (0.3%) and turmeric powder (0.3%)), and solar tunnel (fish soaked in a 5% salt solution for 10 min) drying methods. The results showed that the dried fish produced by the solar tunnel drying method were rehydrated more rapidly than the products produced by the traditional and improved drying methods. The moisture content of the dried H. molitrix was varied from 18.24 to 25.43% on a fresh matter basis. There was no significant (p &gt; 0.05) difference found regarding the protein, lipid, and ash content among the different drying methods on a dry matter basis. The total volatile base nitrogen (TVB-N) contents ranged between 37.58 and 45.03 mg/100 g, and significantly (p &lt; 0.05) the lowest TVB-N was observed in dried fish produced by the solar tunnel drying method. Moreover, the highest peroxide and acid values were found in the traditionally produced dried fish as compared with the fish dried by the improved and solar tunnel drying methods. The aerobic plate count of dried fish ranged from 4.52 to 7.51 log CFU/g. The sensory evaluation results revealed that the solar-dried products showed superior quality than the products produced by the traditional and improved drying methods. The results revealed that the dried fish produced by the solar tunnel drying method provided the best product in terms of physico-chemical, microbiological, and sensory aspects

Effects of stevia (Stevia rebaudiana Bertoni) leaf extracts on the quality and shelf life of refrigerated catla (Gibelion catla) fillets

The effects of stevia leaf extracts (SLE) on the quality and shelf life of catla (Gibelion catla) fillets were assessed during refrigerated storage for 20 days. The fish fillets were treated with aqueous ethanolic (80%) extracts of stevia leaf at various concentrations (1% SLE, 2% SLE, and 3% SLE). The control (distilled water only) and SLE-treated fillets were preserved at 4±1 °C, and chemical (pH, peroxide value (PV), free fatty acid (FFA), thiobarbituric acid reactive substances (TBARS), and total volatile basic-nitrogen (TVB-N)), bacteriological and sensory evaluation was performed periodically for quality assessment. During refrigerated storage, 2% SLE-treated fillets exhibited significantly (p < 0.05) the lowest pH, PV, FFA, TBARS, and TVB-N values compared to other SLE-treated and control fillets. Aerobic plate counts (APC), psychrotrophic bacterial counts, Enterobacteriaceae, lactic acid bacteria, H2S-producing bacteria and Staphylococcus counts of 2% SLE-treated fillets were significantly lower than those of other SLE-treated fillets and control fillets. The maximum APC were 7.22, 7.29, 6.85, and 7.17 log CFU/g for control, 1% SLE, 2% SLE, and 3% SLE-treated fillets at the 12th, 16th, 20th, and 20th days of the storage period, respectively. However, sensory evaluation results revealed that 2% SLE- and 3% SLE-treated fillets had better sensory attributes up to 16th days followed by 1% SLE (12th days) and control (8th days) fillets. Pearson's correlation test and principal component analysis confirmed the relationship among chemical, bacteriological and sensory attributes of refrigerated catla fillets. Based on the chemical, bacteriological, and sensory evaluation results, 2% SLE could be used as a natural additive for catla fillets preservation during refrigerated storage