The effect of enzymatic crosslinking on the viability of probiotic bacteria (Lactobacillus acidophilus) encapsulated by complex coacervation.

Lactobacillus acidophilus were encapsulated by complex coacervation followed by transglutaminase crosslinking, aiming to improve the resistance of the microcapsules and improve the protection for probiotics. Subsequently, microcapsules were dried by freeze drying. The encapsulation efficiency, morphology, thermal resistance, gastrointestinal simulation and storage stability were analysed for wet and dry forms. The treatments offered high encapsulation efficiency (68.20-97.72%). Transglutaminase maintained the structure rounded, multinucleate and homogeneous distribution of probiotics in the microcapsules. In relation to the thermal resistance, in general, microencapsulation was effective in protecting and crosslinked microcapsules demonstrated greater protection for probiotics, obtaining viable cell counts of up to 10 log CFU g-1, approximately. On exposure to the simulated gastrointestinal tract, microencapsulation coupled to crosslinking demonstrated good results and the dry form was more efficient in the protection and the treatment with greater amount of transglutaminase was highlighted (9.07 log CFU g-1). As for storage, probiotic viability was maintained for up to 60 days in freezing temperature, with counts of up to 9.59 log CFU g-1. The results obtained in the present work are innovative and present a promising alternative for the protection of probiotics and their addition in food products.