Diffusion kinetics of nisin from composite coatings reinforced with nano-rhamnosomes

Abstract

This study evaluated the release kinetics of nisin encapsulated in rhamnolipid functionalized liposomes (rhamnosomes), which were further embedded in κ-carrageenan/hydroxypropyl methylcellulose (κ-CR/HPMC) based composite coatings. Release kinetics was analysed in various food simulants e.g. lipophilic (D1) and hydrophilic (A) for 10 days at 4 °C and 25 °C. Thus, diffusion exponent (n), diffusion constant (k), and correlation coefficient (R2) from the power-law model, diffusion coefficient (D) from Fick's second law of diffusion and partition (K) coefficient were evaluated. Diffusion of nisin from nano-active packaging (NAP) was higher for simulant D1 (50% ethanol) than simulant A (10% ethanol) at both temperatures. Partition coefficient values confirmed higher affinity of nisin for rhamnosomes nano-carrier systems (RS-NCS) embedded in biopolymeric coatings than the food simulants. Moreover, the developed NAP exhibited broad-spectrum antimicrobial activity against Gram-positive and Gram-negative foodborne pathogens (L. monocytogenes and E. coli) due to the synergistic effect of nisin and functionalized component of rhamnosomes (rhamnolipids). Thus, these novel RS-NCS embedded NAP can be used as an effective bioactive strategy for improved food preservation during extended shelf-life.