Functional and Nutritional Properties of Fish ProteinHydrolyzate fromDhoma (fohnius dusswnieri)

Abstract

Fish protein hydrolyzate (FPH) was prepared from the minced muscle of an under utilized fish Dhoma (Johnius dussumieri), using a plant proteolytic enzyme, papain. The method involves skinning and deboning of fish followed by washing and incubation of the muscle homogenate in presence of papain at for 2 h. The soluble portion separated after incubation was heated at 950C for 5 min, cooled and freeze-dried. The final product possessing a creamy white colour contained 90% protein and 5% fat. FPH was soluble to the extent of 70% in distilled water but was completely soluble in 0.2N NaOH. The water absorption capacity was 3.0. Emulsifying capacity was found to decrease with increase in protein concentration. The Wettability of the product was excellent in comparison with defatted casein. Nutritive value of FPH assessed by measuring the growth of Tetrahymem pyriformis W could well be compared with that of casein. Incorporation of Sodium tripolyphosphate (NaTPP) and hydrogen peroxide (HjOj) during the preparation of FPH yielded a product which retained colour and retarded the development of off-odours during storage for 3 months at room temperature. FPH prepared by the procedure was devoid of viable organisms.