Sensorial, physicochemical and microbial quality evaluations of sun-dried marine fishes available in the Bay of Bengal of Bangladesh

The present study aimed to assess the sensory, physicochemical, and microbiological quality of five sun-dried marine fish (White sardine- WS, Longjaw thryssa- LT, Doublespotted queenfish- DQ, Chinese pomfret- CP, and Indian threadfin- IT) species (500 gm of each species) collected from Nazirartak fish drying center of Cox's Bazar district, Bangladesh at the month of April 2023. Physical (pH and water reconstitution), biochemical (proximate composition, peroxide value, acid value, conjugated diene and total volatile basic nitrogen), microbiological (total plate count, Escherichia coli, Salmonella sp. and Vibrio sp.) and sensory properties and score revealed that WS showed comparatively better quality than LT, DQ, CP, and IT. pH value and water reconstitution ability of sun-dried WS showed comparatively more acceptable. Significantly (p<0.05) the moisture, protein, lipid, and ash content of those dried fish products were varied from 18.57±0.41% (WS) to 20.38±0.41% (DQ), 59.38±1.05% (DQ) to 61.51±0.53% (WS), 7.61±0.37% (DQ) to 9.68±0.31% (WS), and 9.96±0.27% (LT) to 11.98±0.65% (DQ), respectively. On fresh matter basis, the highest total volatile basic nitrogen value was observed in CP (54.22 mg/100g), while the lowest value was found in WS (29.77 mg/100g). Moreover, sun-dried WS had the lowest peroxide value, acid value, and conjugated diene considered good acceptance. Only WS was deemed more safer and more suitable for human consumption based on total plate count and total Vibrio sp. count. All of the sun-dried fishes were free of the pathogenic bacteria such as E. coli and Salmonella sp., with the exception of CP and IT, where the total E. coli and Salmonella sp. count values were found 2.84 log CFU/g and 3.06 log CFU/g for both species, respectively. Taken together, White sardine (Escualosa thoracata) was found highly acceptable for human consumption based on sensory, physicochemical, and microbial analysis. It has been recommended that elevated focus on processing, handling, hygiene, and storage is crucial to meet consumer expectations of these dried fishery products.