Effects of Processing and Preservation Technologies on Keeping Quality of Labeo rohita: Attributes of Nutritional, Microbial and Sensory.

Background: Fishes being major sources of protein are susceptible to post-harvest losses. Appropriate processing and preservation makes food healthier, safer, tastier, and more shelf-stable. Therefore, an attempt was made to evaluate the effectiveness of different processing and preservation technologies on keeping quality of Labeo rohita (rohu fish), a widely found ray-finned species in South Asia that is important for aquaculture. Methods: Raw fish fillets were subjected to different processing and preservation technologies including freezing, sun drying, mechanical drying, salting, microwave processing, and marinating to determine their effects on keeping quality. Consequently, sensorial attributes, proximate composition, mineral (calcium (Ca), iron (Fe), and zinc (Zn)) contents and microbiological analyses were carried out. Obtained data were analyzed statistically and compared using one-way analysis of variance (ANOVA) followed by Fisher's LSD test at 5% level of significance. Results: The moisture, protein, fat, ash, and carbohydrate contents were 13.01-77.29, 8.62- 52.57, 0.86-18.69, 1.34-12.72, and 1.13-27.22%, respectively in different processing and preservation technologies. Drying manifested to be the efficient method in terms of preserving proteins and fats while retention of sensory attributes was obtained in freezing. The contents of Ca, Fe, and Zn were 120.05-227.97, 0.54-1.14, and 0.72-2.04 mg/100 g, respectively. In addition, maximum retention of Zn, Fe, and Ca contents were observed in freezing, sun drying, and marinating, respectively. Furthermore, total bacterial count was in the range of 0- 2.6×104 Colony Forming Unit (CFU)/g and no coliforms were detected in any of the raw and processed fish fillets. Results of microbiological study revealed that microwave processing is highly efficient to reduce microbial loads in processed fish. Conclusion: Combination of different processing and preservation technologies might be useful to the efficient management of fishery resources. Therefore, further research into these combinations is essential to ensure that the nutritional value of fish is preserved. [ABSTRACT FROM AUTHOR]