Abstract
Propylene glycol alginate (PGA) was incorporated into Alaska pollack-surimi films to improve their mechanical properties. The tensile strength of PGA-surimi films prepared at pH 11 was twice as high compared to surimi films prepared at pH 7. Elongation at break was not affected by the incorporation of PGA. The water vapor permeability, film and protein solubility, and protease digestibility of PGA-surimi films were not markedly influenced by pH. The film-forming mechanism of PGA-surimi films was investigated on the basis of the changes in SDS-PAGE patterns and the available lysine content. The results revealed that the formation of cross-linkages between ε-amino groups of lysine residues in surimi proteins and mannuronic acid esters of the PGA above pH 10 was responsible for the increased tensile strength of films.
