Cross‐Linking of Myosin Heavy Chains from Cod, Herring and Silver Hake During Thermal Setting

Abstract

ABSTRACTCross‐linking of myofibrillar proteins extracted from cod (Gadus morhua), herring (Clupea harengus) and silver hake (Merluccius bilinearis) was studied in 0.6M NaCl, pH 6.5 at 40°C and evaluated turbidimetrically and by SDS polyacrylamide gel electrophoresis coupled with l‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide as a zero‐length crosslinker. Turbidities of heat‐treated cod and silver hake myofibril/myosin solutions were significantly higher than those of herring. Electrophoretic results showed that the myosin heavy chain (MHC) was the principal myofibrillar protein cross‐linked to form a polymerized complex during the heat treatment. Cross‐linking ability of MHC from the three fish species was different; herring MHC formed only small polymers (n≦3) but cod and silver hake MHC formed both small and large polymers (n≦6).