Abstract

Market samples of three sun-dried freshwater fish species namely Indian major carp (Labeo rohita), snake headed fish (Channa striatus), and a type of eurasian catfish (Wallago attu) were included in this study. The quality of the sun-dried fish samples were evaluated by examining physical properties, biochemical composition, and reconstitution behaviour. The safety aspect of the sun-dried fish samples were studied by the detection of heavy metal, total viable bacterial count (TBC), aerobic plate count (APC) and Total volatile base-Nitrogen (TVB-N). According to the physical characteristics such as colour, odour, texture, it appeared that the L. rohita and C. striatus were of better quality than that of the W. attu which had already developed rancid odour, and bitter taste. The examined samples were brownish to light brown compared to the attractive cream colour of a freshly prepared samples. The products had moisture content ranging from 19.17 to 23.12%. The protein content ranged from 49.23 to 62.85%. Lipid and ash content were in the range of 4.92 to 11.0% and from 11.11 to 18.89%, respectively. C. striatus contained the highest protein content (62.85%) and W. attu contained lowest protein (49.23%) on moisture free basis. The result of heavy metal analysis of the sun-dried fish samples showed that, in sun-dried L. rohita, Arsenic (As) was 0.001 mg/g, Cadmium (Cd) was 0.53 mg/g, and Chromium (Cr) was 0.025 mg/g. In the sample of sun-dried C. striatus  As was 0.003 mg/g, Cd was 0.089 mg/g and Cr was 0.054 mg/g; while in the sample of sun-dried W. attu As was 0.004, Cd 0.097, and Cr 0.068, which were within the acceptable limit for human consumption. The TBC of the experimental samples ranged from 1.84 × 10⁴ to 5.3 × 10⁶ per g of the dried samples. The total volatile base Nitrogen (N) content of the dried fish samples ranged from 7.54 to 8.32%. Reconstitution rate was found to be faster in C. striatus  and L. rohita but slower in W. attu.

Key words: Total volatile base-Nitrogen, sun-dried, trace elements, fish.