Abstract: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 > 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 < 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.

An investigation was carried out to compare the physical, chemical, microbiological and sensory properties of three freshwater dried fish products of Wallago attu Bloch & Schneider, 1801 (Siluriformes: Siluridae), Channa striatus (Bloch, 1793) (Perciformes: Channidae) and Glossogobius giuris (F. Hamilton, 1822) (Perciformes: Gobiidae). The traditionally sun dried fishes were collected from Kawran Bazar Fish Market, Dhaka, Bangladesh. Results showed that the water reconstitution properties varied among the dried fishes where maximum rehydration was observed in the C. striatus at room temperature, 40 oC and 60 oC. Moisture content of W. attu, C. striatus and G. giuris were 22.70% +/- 0.45%, 18.75% +/- 0.58% and 21.93% +/- 0.54%, respectively; the protein content were 61.85% +/- 0.99%, 66.44% +/- 1.02% and 62.83% +/- 0.87%, respectively; the lipid content were 6.21% +/- 0.93%, 6.81% +/- 0.72% and 5.98% +/- 0.55%, respectively, and the ash content were 6.79% +/- 1.11%, 6.49% +/- 1.29% and 7.83% +/- 0.98%, respectively. Peroxide value, acid value, pH, TVB N value and aerobic plate count were found to be highest in W. attu followed by G. giuris and C. striatus. Results of this study revealed that traditionally sun dried fish products were acceptable quality in terms of physico-chemical, microbiological and sensory aspects.

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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 5–6 days until the moisture content reduced to approximately 10–15%. The dried fish was then packed into airtight polyethylene bags and stored at ambient temperature (24 to 29 °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 < 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.

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