Effect of unmodified starch on viability of alginate-encapsulated Lactobacillus fermentum CECT5716

•The mean diameters of microparticles with starch were <30 μm.•Particles have a spherical shape and smooth surface without pores.•Internal gelation is appropriate for the microencapsulation of Lactobacillus.•The mix of alginate and starch shows better results than the alginate alone.•The viability was not modified after 45 days at 4 °C in the formula with starch.

Probiotics are one of the most promising ingredients for the production of functional foods or nutraceutics. However, when incorporating probiotics into a food matrix, the main problem is their low resistance to different environmental and technological conditions.Microencapsulation is a good method in order to protect probiotics. The aim of this study was to apply the Ionic Internal Gelation Technology to protect Lactobacillus fermentum CECT5716.We evaluate the encapsulation efficiency of two different formulations, the first one with alginate (5 g/100 mL) as a supporting material and the second one with a mix of alginate (5 g/100 mL) and unmodified starch (1 g/100 mL).Results show that the viability of probiotic decreases in 3 log cell numbers in the case of the formulae with alginate and in 0.3 log in the formulae with alginate and starch. Moreover, the last one allows us to obtain a suitable particle size (<30 μm) and the viability of probiotic was not modified after 45 days at 4 °C.In conclusion, Internal Gelation Technology using alginate and starch seems to be a suitable procedure for protecting this probiotic strain and the formulae with alginate and starch is more efficient than the one with just alginate.