Changes in Microbial Quality of Tilapia Fish during Frozen Storage and Their Fried Products

The total quantity of catch fish recorded 1,706,273 tones, while the total quantity of Exports and Imports of fish were 47812 and 311068 tones, respectively. Annual average share per capita of fish was 21.64 kg [1]. Global changes in consumer lifestyle marked by increasing demand for nutritional and healthy food products have spurred the continuing rise in demand for fresh and ready-to-cook fish and fishery products. This rising demand for ready to eat fresh instead of frozen fish requires the use of preservation procedures that can add value and reduce postharvest losses [2-5]. Freshly caught fish is variable and delicate food due to soft and moist texture, sweat flavor and great nutrition and health components. However because of its high moisture (high water activity (aw ≥ 0.95), post mortem pH of about 5.2 and free amino acids combined with lower level of connective tissue compared with other muscle foods, seafood is more susceptible to spoilage and therefore have short shelf-life. Hence it's essential to take immediate steps to preserve the fresh quality and safety of fish products. Seafood quality deterioration occurs from wide range of causes, such as poor catching practice; poor handling and keeping of raw materials and inefficient refrigeration and storage. To ensure that the fresh quality is well preserved, and to establish the most efficient methods for preservation of seafood quality, both objective and subjective methods of quality analysis should be performed. Chemical, biochemical, physical and microbiological methods have been used as objective methods to evaluate the quality of fish during chilled storage [6]. Fresh fish is a highly perishable product due to its biological composition. This condition is favorable for the growth of micro-organisms, which leads to eventual spoilage. Provoking loss of essentially fatty acids, fat-soluble vitamins, protein functionality and production of biogenic amines and formation of off-odors should be considered. Therefore, fishes need to be preserved, because they get spoilt very quickly even in temperate regions [7,8]. Freezing preservation of food has been used for thousands of years because of high product quality. It is a usual method to preserve commercial fish since it stops chemical and microbiological degradation, and is an excellent method of preserving the organoleptic attributes of fish flesh during prolonged periods of time [9,10]. Frying is one of the oldest methods of food preparation. It improves the sensory quality of food by formation of aroma compounds, attractive color, crust and texture. Deep fat frying is a process where in a food is allowed to be immersed and held in hot fat for cooking. Fried foods have a distinct position, attributed to their characteristic color, flavor and aroma. During this process, complex operations could occur involving numerous chemical and physical changes such as starch gelatinization, protein denaturation, moisture evaporates and forming coating [11]. The main objective of the current study could be summarized in Determine the microbial quality of fried Tilapia fish during frozen storage.