Preservation Methods and Storage Period Affect the Mineral and Moisture Composition of Freshwater Fish Species

摘要

The study was designed to investigate the effect of both the duration of storage and preservative methods on moisture and minerals (Ca, Mg and K) composition of five different fresh water fish species namely, Red Breasted Bream (Tilapia rendalli ),African Catfish(Clarias gariepinus ),Mabusi(Chrysichtys mabusi ). Three Spotted Bream(Oreochromis andersonii ) andNile Tilapia(Oreochromis niloticus ). These fish species were collected from Lake Kariba, a fishery located in the Southern province of Zambia. Each fish species was subjected to four months of both frozen and salted storage and analyzed for moisture and mineral composition at intervals of one month. Moisture decreased in salted fish, but increased in frozen fish with increasing duration of storage. Mineral composition (Ca, Mg and K) in both treatments decreased variedly with duration of storage across species. Generally, the nutrients reduced more in the first month of storage and immediately after treatment. The results suggest that these preservation methods and together with the storage period do have a negative effect on the nutritional values of fish species. Hence, fish should be consumed while fresh and if it is to be stored, the period must be as short as possible to provide optimal levels of nutrients, particularly minerals.