IMPACT OF SPICE TREATMENT ON THE QUALITY AND SHELF LIFE OF SUN DRIED TAKI

Abstract

A study was conducted to evaluate the impact of spices (turmeric, chilli, and their combination) treatment on the quality of dried Snakehead (Channa punctatus) locally called taki immediate after production and subsequent storage from June-October, 2015. The raw taki fish with excellent quality were collected from the local market, treated with 2% turmeric, 2% chilli and a combination of 2% turmeric and chili after de heading, gutting and washing and dried under sun. A control group was also dried without spices treatment. Another group of fish was also considered for sun drying without spices treatment that were judged as a deteriorated fish by the panel expert for better understanding of the quality of dried fish made from rejected fish. Similarly, samples of traditional sun dried taki were also purchased from local market to make a comparison among the products. The spices treated dried fish showed excellent quality when judged by sensory and nutritional quality than those of the control, deteriorated and traditional sun dried fish products. When the protein content was evaluated immediate after drying, it has been found that the fish treated with spices have higher percentage of protein (range 62% to 67%) than those of the others (58% to 62%).When these dried products stored for a period of 5 months under airtight plastic container, it was observed that the quality loss was higher in untreated dried fish and showed rejected quality attributes at the end of the experimental period. The protein percentage decreased with the increase of storage period. The percentage of protein of this group was within the ranges of 56% to 62% while this range was 62% to 67%initially.The range of lipid contents was 6% to 9% initially which finally decreased to 35%. The ash content was found within the range of 10% to 12% and after 150 days of storage period it changed to 7- 9% in laboratory made samples. The highest ash contents from 15 - 20% were observed in the traditional dried fish samples collected from the local retail market. The percentage of moisture showed reverse trend when analyzed the proximate composition of these products. Moisture contents of the final products showed within the range of 18- 23% while the initial percentage was 15-19%. The experimental dried taki were individually soaked in water bath in two temperature points as 60°C and 80°C at different time intervals. Reconstitution capacity of the dried samples increased with the increase of water temperature and soaking time. Best water reconstitution percentage was found in the fish samples treated with spices than those of others. The fungal infestation was higher in the untreated and market collected dried fish products. The insects (Dermestes sp.) infestation was observed within 2 months of storage period with lower infestation in the spices treated products. This result indicated that the spices have an impact on the quality of the final products as well as maintaining quality even longer period of storage. The antimicrobial and anti-insect infestation properties of the spices may act upon the fish which ultimately kept the products in acceptable quality during storage period. Therefore, the spices specifically turmeric and chilli could be an excellent natural preservative for maintaining dried fish quality during drying and storage. It also could be an alternative preservative against the banned and unsafe chemicals. This technology can be adopted for commercial purposes to reduce the microbial and insect threat on dried fish products.