Improving nisin production by encapsulated Lactococcus lactis with starch/carboxymethyl cellulose edible films.

Abstract

In this study, Lactococcus lactis was embedded in a film of corn starch (NS) and carboxymethyl cellulose (CMC) prepared using a casting method. At a CMC:NS ratio of 5:5, the composite film had the best comprehensive properties. Scanning electron microscopy images clearly showed that L. lactis was effectively embedded. The film with 1.5 % L. lactis showed the best performance and the lowest water vapor transmission rate (5.54 × 10-11 g/m s Pa. In addition, the edible film retained a viable count of 5.64 log CFU/g of L. lactis when stored at 4 °C for 30 days. The composite film with 1.5 % L. lactis showed the highest release of nisin (3.35 mg/mL) and good antibacterial activity against Staphylococcus aureus (53.53 %) after 8 days. Therefore, this edible film is a viable alternative antimicrobial strategy for the active packaging of foods containing low moisture content.

Keywords: Carboxymethyl cellulose; Edible film; Lactococcus lactis; Starch.