Bioactivity evaluation of microbial exopolysaccharide and its use as an encapsulating agent for Lactobacillus acidophilus (LA-3)

Microbial exopolysaccharides present bioactive and technological characteristics of interest to the food and pharmaceutical industries. This study aimed to evaluate the bioactivity of the exopolysaccharide - EPS-LN60 obtained from L. plantarum DF60Mi and its use as an encapsulating agent for Lactobacillus acidophilus LA-3. The prebiotic score, antioxidant activity, and cytotoxicity in human tumor and non-tumor cells were determined. Solutions of 0% (F0), 0.5% (F1), and 1.0% (F2) of EPS were used as a coating for alginate capsules containing LA3, which were evaluated for morphology, survival of LA-3 during refrigerated storage and after exposure to in vitro gastrointestinal conditions. EPS-LN60 had a higher prebiotic capacity (1.45 +/- 0.17) compared to the fructooligosaccharide (0.24 +/- 0.05) and an antioxidant activity of 1862 +/- 23.08 mu M FeSO4/g. Furthermore, EPSLN60 inhibited tumor cell growth by 36%+/- 2.78%. The capsules coated with EPS-LN60 were spherical, uniform, and efficient toward LA-3 survival (85%) after 20 days of storage. F0 did not have viable cells after 10 days. EPSLN60 provided additional protection to the capsule, preventing loss of viability during gastrointestinal simulation conditions, resulting in survival rates greater than 86%, which was not observed in F0 when submitted to the same conditions. Therefore, the potential of EPS-LN60 was demonstrated in terms of its bioactivity and its use as an encapsulating agent for L. acidophilus LA-3, with the possibility of future exploitation as a functional ingredient by the food and pharmaceutical industries.