Effect of potassium sorbate on properties and antibacterial effect of konjac glucomannan/zein composite films

In this paper, konjac glucomannan and zein were used as the substrate, together with additions of antimicrobial agent ( potassium sorbate) at different content to prepare composite films, and the physicochemical properties and antibacterial effect of the composite films were studied.The results showed that the addition of potassium sorbate had no significant effect on the composite films thickness ( p > 0.05) and the water vapor transmission rate and transparency of the composite films decreased with the increased potassium sorbate content. The elongation at break of the composite films increased significantly with the increased potassium sorbate content ( p < 0.05) , and when the content of the composite film was 12%, the elongation at break was 36.02%, one times larger than that of composite film without potassium sorbate.When the addition of potassium sorbate was6%, the tensile strength of the composite film was the highest, which was 58.78 MPa.With the increased the potassium sorbate content, the antibacterial effect of the composite films on Escherichia coli, Staphylococcus aureus and Bacillus cereus was significantly enhanced.When the potassium sorbate content was 12%, it could prolong the shelf life of fish for 4 days at 4 ℃.The composite films was suitable to be used in food fresh-keeping packaging.