The role of bacterial fermentation in the hydrolysis and oxidation of sarcoplasmic and myofibrillar proteins in Harbin dry sausages

Abstract

Pediococcus pentosaceus, Lactobacillus curvatus, Lactobacillus sake and Staphylococcus xylosus were evaluated to determine their role in the hydrolysis and oxidation of sarcoplasmic and myofibrillar proteins in Harbin dry sausages. Electrophoresis analysis showed that the hydrolysis of sarcoplasmic and myofibrillar proteins in dry sausages inoculated with bacterial strains was more severe than that in the non-inoculated control. The predominant free amino acids at the end of the fermentation were glutamic acid and alanine, both of which are involved in creating a desirable taste. The inoculation of dry sausages with bacterial strains, especially mixed strains, significantly decreased carbonyl formation and sulfhydryl loss in sausages (P<0.05). Both hydrolysis and oxidation led to increased surface hydrophobicity in sarcoplasmic and myofibrillar proteins. Fermentation of dry sausage with multiple bacterial strains could contribute to flavour formation via flavour precursors. The results demonstrate that Harbin dry sausage can be inoculated with a starter culture mixture of P. pentosaceus, L. curvatus and S. xylosus to improve flavour formation.

Keywords: Bacterial fermentation; Dry sausage; Myofibrillar proteins; Protein hydrolysis; Protein oxidation; Sarcoplasmic proteins.