Development and Characterization of Nisin-Loaded Niosomal Nanoparticles for Enhanced Preservation Efficacy

Background: Bacteriocins are peptides produced by lactic acid bacteria and have been considered as natural food preservatives. Nisin is the only bacteriocin licensed as a bio-preservative. Its application is limited due to uncontrolled reactions with food compounds and its decomposition. Encapsulation is one solution that can preserve this bacteriocin and control its release in food products. Objectives: The present study aimed to encapsulate nisin in niosomes and investigate its characteristics to achieve an optimal formula based on formulation variables, cholesterol to surfactant ratio, maximum loading percentage, and sustained release pattern for use as a preservative-containing nanocarrier in the food industry. Methods: In this study, a completely randomized design was used to construct and select the optimal niosome formulation by the thin film method. In this design, 6 treatments were prepared based on two variables: Surfactant to cholesterol ratio (70:30 and 80:20) and molar ratio (Span 60 to Tween 80). The effect of these variables on the encapsulation efficiency and nisin release pattern was investigated. Formula F2, with a surfactant to cholesterol ratio (70:30) and a surfactant molar ratio of (1:1), with the highest encapsulation efficiency (36%) and sustained release pattern, was selected as the optimal formula. Its morphological and physicochemical indexes, including shape, size, Dispersion Index, and internal reactions, were investigated by dynamic light scattering (DLS), atomic force microscopy (AFM), and Fourier transform infrared (FTIR) methods. Results: The optimal formulation of niosome had a particle size of 200 nm, a loading efficiency of 36%, and a nisin release of 32% in 72 hours. Conclusions: The results showed that niosome can be used as a suitable proposed nanocarrier for the encapsulation of nisin in the food industry.