Gelation of crocodile myofibrillar protein - κ-carrageenan mixtures in two low-NaCl solution

Abstract

Crocodile meat is a novel reptile meat source, but its processing method is rare. This study investigated the effect of κ-carrageenan addition and partial substitution of NaCl on the gel properties of crocodile myofibrillar protein (CMP). Result showed that CMP formed gel when temperature above 60 ℃. The water-holding capacity, gel strength, denaturation degree, sulfhydryl content covalent bond and hydrophobic bond of gel in KCl solution were significantly higher than those in CaCl₂ solution (P < 0.05). K⁺ induced CMP to form a tight network structure with uniform small pores though covalent and hydrophobic bonds, but the gel properties were reduced by κ-carrageenan. In CaCl₂ solution, κ-carrageenan improved the gel structure by filling the protein network through hydrogen bonding. Therefore, it can be concluded that KCl is better than CaCl₂ in the manufacturing of low-sodium crocodile foods. Moreover, κ-carrageenan was only beneficial to gel quality in CaCl₂ solution.

Keywords: Crocodile myofibrillar protein; Gelation properties; NaCl substitution; κ-carrageenan.