Development of an ethnic ready-to eat fish product ‘Ah-eemo’ from Indian mackerel (Rastrelliger kanagurta) and its quality characteristics

Abstract

Ah-eemo is an indigenous dish of Tripura prepared from small (freshwater) fishes. The fish is wrapped with banana leaf and steam cooked or sometimes by burying it under heap of ash (burned firewood) followed by burning fire over it. The product needs to be consumed within a short period of time after preparation. Therefore, the objectives of the present work were to improve the method of preparation and to extend the shelf life of Ah-eemo without losing its organoleptic characteristics and nutritional quality. Ready-to eat Aheemo was prepared from Indian mackerel by improving the methodology. Polyester polyethylene laminate pouches were selected as a packaging material to contain the wrapped fish. The packaging was performed at 93 per cent vacuum. Optimized cooking time and temperature were 35 min and 98 degree celsius with reference to organoleptic properties. A refrigerated (2-4 degree celsius) storage study was carried out to evaluate the shelf life of the product. Colour & texture, microbial load and biochemical properties such as lipid peroxidation products and nitrogenous compounds have been analyzed. Effect of cooking on protein fractions of ‘Ah-eemo’ was studied. SDS-PAGE confirmed no significant change in major protein fractions during the process of cooking. Microbial load of fresh mackerel and Ah-eemo were 5.94 log cfu/g and 2.83 log cfu/g respectively. Comparative study of fatty acids profiles for fresh mackerel, marinated mackerel and Aheemo samples were carried out during the storage period. Significant difference in MUFA content were observed in fresh mackerel and Ah-eemo samples. But unlikely, PUFA content showed least variation throughout the study period. EPA and DHA content of Ah-eemo varied from 6.81- 9.36 per cent and 19.98-22.66 per cent respectively. Hence, a hygienic and nutritious RTE Aheemo with a shelf life of 30 days under refrigerated storage was achieved by the improved methodology.