Assessment of Nutritional Quality of Smoked Hilsha (Tenualosa ilisha) Treated with Different Spices during Storage at Various Temperatures

Aims: The present research was conducted to investigate the effect of different spice formulations on the nutritional and microbial quality of smoked hilsha (Tenualosa ilisha) stored under sealed and vacuum-sealed conditions at two storage temperatures: room temperature (28-30°C) and refrigeration (4-8°C). Study Design: The experiment followed a three-way factorial design with five spice treatments, two packaging methods, and two storage temperatures, using three biological replicates with random assignment of fish chunks to treatments and storage units for unbiased evaluation of sensory, nutritional, biochemical, and microbial quality. Place and Duration of Study: The study was carried out at Fish Processing and Quality Control Laboratory of the Department of Fisheries Technology, Faculty of Fisheries, Bangladesh Agricultural University (BAU), Mymensingh during the period of August 2022 to January 2023. Methodology: Freshly collected hilsha were dressed, cut into chunks, dipped in spice mixtures, and smoked at 70-80°C using an improved traditional kiln. Five treatments were applied: T0 (control, no spice), T1 (onion, garlic, ginger, mustard seed, chili), T2 (onion, garlic, ginger), T3 (ginger, mustard seed, chili), and T4 (ginger, chili). After smoking, products were cooled, packed, and stored for sensory evaluation (9-point hedonic scale), proximate composition (moisture, protein, lipid, ash), biochemical indices (TVB-N, pH, PV), and microbial analysis at different storage intervals. Results: Results showed that storage temperature, packaging method, and spice treatment had a significant impact on the quality of smoked hilsha. Sensory scores for flavor, color, and texture declined more rapidly in samples stored at room temperature, with acceptability lost within 6-10 days, while refrigeration extended shelf life up to 30-42 days, particularly under vacuum-sealed conditions. Proximate analysis indicated a progressive increase in moisture content with storage time, while protein, lipid, and ash contents decreased, with the highest nutrient retention observed in T1. Biochemical indices (TVB-N, pH, PV) increased steadily across treatments, but the rise was significantly lower in spice-treated samples compared to the control (T0). Microbial load also followed an increasing trend, with vacuum-sealed and refrigerated samples showing the slowest growth. Conclusion: Overall, T1 consistently outperformed other treatments in maintaining sensory quality, nutrient stability, and delaying spoilage indicators, while T0 exhibited the poorest quality retention. The findings suggest that spice incorporation, especially the T1 combination, along with vacuum packaging and refrigeration, can effectively enhance the storage stability and commercialization potential of smoked hilsha products.