Liquifying Cod Fish Frames Under Acidic Conditions With a Fungal Enzyme

Abstract

An acidic protease (Newlase A from Rhizopus niveus, Amano) was evaluated as to its ability to reduce viscosity of ground cod fish frames without excessive hydrolysis. Newlase A had an optimal pH of 3.5 and an optimal temperature of 60C with Azocoll as substrate. the enzyme was more stable in the ground fish mixture at pH 3.5 than it was in citrate:phosphate buffer of the same pH. the enzyme hydrolyzed the fish proteins more extensively and decreased the viscosity of the ground fish more between 40–50C over an extended time period than at its optimal temperature of 60C. It is likely that the lower optimal temperature under these conditions is related to its greater stability at the lower temperatures. the energy of activation of the deactivation of the enzyme was 44.5 Kcal per mol‐degree. Over a period of 75 min at 45C there was a decrease in viscosity of the ground fish with added enzyme of some two orders of magnitude. After a 3‐h incubation, total soluble protein increased from 30% to 48%; the amount of each molecular size fraction produced decreased in the following order: 1–3, < 10, < 1, and 3–10 kdaltons.

Utilization of Fish Processing By-Products in the Gelatin Industry

“…(45) Through the control of the process parameters such as pH, time, and enzyme/substrate ratio, it is possible to produce hydrolysates whose components may present some interesting properties. However, the studies done on whole fish by-products of protease-assisted hydrolysis are mainly evaluated for their nutritional and functional properties as shown by many papers published on fish proteins such as sardine, (46) cod (47) and salmon. (48) Several processes have been proposed to produce gelatin by the use of naturally occurring enzymes.…”

Influence of process variables on the hydrolysis of shark muscle protein / Influencia de las variables de proceso en la hidrólisis de proteína del músculo de tiburón

“…The specific optimum value would vary with different substrates (Olsen and Adler-Nissen, 1979;O'Meara and Munro, 1984). Similar temperature influences have been observed in hydrolytic reactions of food proteins using fungal (Ferreira and Hultin, 1994) and animal (Surowka and Fik, 1994) proteases. pH of hydrolysis Both DH and NR attained maximum values at pH 8.0 (Figure 3).…”

Optimization and partial purification of a protease produced by selected bacterial strains grown on trash fish meal substrate and its antagonistic property against bacterial pathogens

“…Traditionally, much of this material has been converted to powdered fish meal by a combined process of cooking and separation of soluble from insoluble (Ferreira and Hultin, 1994). In view of their high protein content of high quality, fish represents a potential source of industrial peptones for a wide range of applications (Prakash et al, 2011).…”