Abstract:

Unheated or microwave heated channel catfish byproducts with a central temperature of 90 ℃ were used as raw material to prepare fish silage. Both fish silages obtained were stored for 40 days at 6, 10, 15, 20, 30, 40 ℃ and were measured for basic chemical composition, amino acid composition, trace element composition, degree of hydrolysis and acid soluble protein content at different storage time points. Results showed that 40-day storage at 40 ℃ resulted in an increase by 12 g/kg of protein content in fish silage prepared from unheated channel catfish byproducts compared with freshly prepared fish silage, whereas the contents of fat, ash and water were decreased by 3, 3 g/kg and 31 g/kg, respectively. However, no obvious changes in amino acid composition and inorganic element composition were observed. Storage conditions such as temperature and time made a big difference to the degree of hydrolysis and acid soluble protein content of fish silage prepared from unheated channel catfish byproduct, whereas there were no obvious changes in the degree of hydrolysis and acid soluble protein content of fish silage prepared from microwave heated channel catfish byproducts with changing storage conditions.

Key words: channel catfish, fish silage, storage temperature, storage time