MILK FERMENTATION BY EPS-PRODUCING PROBIOTICS AS A STRATEGY FOR THE DEVELOPMENT OF PRODUCTS FOR DYSPHAGIC INDIVIDUALS

Exopolysaccharides (EPS) are extracellular carbohydrate polymers that can be secreted by microbial cells. These polymers may present several bioactivities such as antimicrobial, immunomodulatory, antidiabetic and prebiotic activities. Additionally, the production of EPS by bacteria in fermentation processes can increase the viscosity of fermented products. Thus, these compounds have the potential to be explored as thickeners in food products intended for individuals with dysphagia, a condition characterized by difficulty in swallowing, which involves neurological and muscular interactions and may be related to aging or pathologies. This study aimed to evaluate the potential of commercial lactic cultures to produce EPS and improve the viscosity of fermented milks. Reconstituted powdered milk (10% solids) was fermented by different commercial lactic cultures to obtain yogurt (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) and probiotic fermented milk (Streptococcus thermophilus, Lactobacillus acidophilus and Bifidobacterium animalis ssp. lactis). The fermented products were evaluated for EPS production and subjected to texture analysis to evaluate the parameters of firmness, consistency, cohesiveness, and viscosity index. Samples of milk acidified with glucono-delta-lactone (GDL) and with the addition of a commercial thickener in concentrations to obtain nectar-like (mildly thick) and honey-like (moderately thick) consistencies were used to compare the texture parameters. The evaluated cultures presented similar fermentation profiles and did not differ in EPS production. The acidification of milk by fermentation or by adding GDL contributed to the firmness and consistency of the product. However, the probiotic fermented milk presented a higher viscosity index than the yogurt and GDL-acidified samples and was equivalent to the honey-like consistency standard. Thus, the results demonstrated that the probiotic culture used increased milk viscosity during fermentation, and the difference in the viscosity index of the fermented products might be associated with the composition of the EPS secreted by the cultures.