Optimization and Characterization Freeze Dried Fish Protein Hydrolysate Production

The production of fish protein hydrolysate from underutilized fish species is attracting the industrial interest for increasing the rich protein values. The central composite design was used to optimize the degree of enzymatic hydrolysis of freeze-dried fish protein hydrolysate (FPH) production by the application of commercial Alcalase on the recovery mixed small fish protein. The effects of time, temperature, pH and enzyme concentration on the degree of hydrolysis (DH) of five strains of fish as Rastrelliger brachysoma (short-bodied mackerel), Rastrelliger kanagurta (Indian mackerel), Leiognathidae (Ponyfish), Amblygaster leiogaster (Smooth belly sardinella) and Selaroides leptolepis (yellow-stripe scad) were experimented. Result showed that the FSH production was optimized at 2.85%v/w enzyme concentration at 61 °C, pH 8.50 for 27 min with 89.42% DH. Mathematical model was proposed and validated under the optimum condition. The high proportion (46.43%) of smaller molecular weight <1 kDa was found in hydrolysate. Freeze-dried fish protein hydrolysate was produced and revealed that three predominant amino acids as glutamine, lysine and alanine. Based on amino acid compositions, the waste fish hydrolysate showed nutritional value and high potential for the applications of feed supplementation.