Spray-drying microencapsulation of nisin by complexation with exopolysaccharides produced by probiotic Bacillus tequilensis-GM and Leuconostoc citreum-BMS

Abstract This work aims to encapsulate nisin by complexation with exopolysaccharides (EPS), produced by Bacillus tequilensis -GM and Leuconostoc citreum -BMS, namely EPS-GM and EPS-BMS, respectively, using spray-drying technique, and to evaluate the effect of this encapsulation on the structure of nisin. Results related to suspensions turbidity showed that EPS/nisin complexes were formed through electrostatic attractions. These interactions were confirmed by Fourier transform infrared (FTIR) analysis. Scanning electron microscopy (SEM) micrographs of the spray-dried complexes revealed the presence of well-separated spherical microcapsules. Besides, results obtained by UV spectra showed that no significant changes occurred on EPS-GM/nisin microcapsules suggesting that this EPS may act as protective agent of nisin structure against spray-drying conditions.