Proteolytic Activity in the Sarcoplasmic Fluids of Parasitized Pacific Whiting (Merluccius productus) and Unparasitized True Cod (Gadus macrocephalus)

Abstract

Proteolytic enzymes in the sarcoplasmic fluid of Pacific whiting (Merluccius productus) were studied to determine which proteases might be involved in the severe textural defect associated with this species. The results were compared to those obtained for true cod (Gadus macrocephalus), a fish having firm texture. Two pH optima of enzymic activity were noted for whiting, pH 3.5–3.9 and 7.1–7.2. Two pH optima were also observed for cod, pH 3.2–3.6 and 7.8–8.0. Whiting but not true cod contained enzymic activity similar to cathepsin B. Cathepsin C activity was greater in whiting than in cod. Copyright © 1983, Wiley Blackwell. All rights reserved