Avaliação da sobrevivência de lactobacillus acidophilus la-05 microencapsulado incorporado em leites e extratos hidrossolúveis durante digestão simulada

Abstract

Probiotics are defined by the World Health Organization as living microorganisms that, when consumed in adequate quantities, confer benefits to the health of those who ingest them. However, in order for these microorganisms to provide benefits, they must tolerate certain conditions, such as storage and exposure to the gastrointestinal tract. Thus, the microencapsulation of probiotic strains has been studied in order to protect these microorganisms from the adverse conditions to which they are exposed, keeping the cell count viable up to the intestine. Among the probiotic microorganisms most studied and applied in foods are those of the genus Lactobacillus, particularly L. acidophilus. Therefore, the present study evaluated the survival of microencapsulated Lactobacillus acidophilus La-05 incorporated in different food matrices during simulated digestion. L. acidophilus La-05 was microencapsulated through the external ionic gelation technique with sodium alginate and chitosan, forming calcium alginate (MA) microparticles and chitosan-coated calcium alginate (MAQ). Lyophilized MA and MAQ were referred to as MAL and MAQL. The results revealed compatibility between alginate and chitosan with the probiotic strain, presenting an encapsulation efficiency of 99.27% for MA, 99.33% for MAQ (0.5%), 92.68% for MAL and 91, 87% for MAQL. MAQ (0.7%) showed an efficiency of 64.82%, demonstrating that the concentration of the microencapsulating agent influences the viability of the strain. At the end of the simulated digestion process, L. acidophilus La-05, in its free form, presented a decrease of 3.39 log CFU / mL in the water-soluble rice extract, 3.16 log CFU / mL in the water-soluble soybean extract, 2.82 log CFU / mL in goat milk, 2.61 log CFU / mL in bovine milk. On the other hand, the MAL and MAQL obtained reductions of 1.31 and 1.29 log CFU / mL in rice extract, 1.23 and 1.43 log CFU / mL, respectively, in soybean extract, 0.96 and 1.17 log UFC / mL in goat milk, 1.09 and 1.29 UFC / mL in bovine milk. The strain in the MAL and MAQL presented better results than in its free form, with a decrease of less than 2 log CFU / mL in all matrices evaluated. The results showed that both goat milk and bovine milk were good carriers of probiotics. Furthermore, the viability of L. acidophilus La-05 was also maintained when added to the vegetable matrices, thus presenting an alternative for the incorporation of probiotics into non-dairy products.