Antagonism and survival of probiotics encapsulated in functional yogurt-like fermented vegetable beverage

Abstract

This research aimed to evaluate the survival of encapsulated and free probiotics in a functional plant-based beverage. The fermented vegetable drink was developed from the water-soluble extract of red pigmented rice and added from the strains of Bifidobacterium animalis ssp. Lactis and Lactobacillus acidophilus, were added free and encapsulated. Encapsulation was performed by the ionic gelation method of the 2% alginate solution with the probiotic cultures. The microbiological analysis, pH and acidity, respectively, were conducted at intervals of 0, 15, and 40 days post-fermentation and cold storage. The physicochemical and bioactive compound analyses were: Acidity, pH, moisture, density, ash, lipids, proteins, carbohydrates, determination of total phenolics and total anthocyanins. The antimicrobial activity was carried out by the microdilution method against pathogenic bacteria. The physicochemical analyses obtained results above expectations, especially the high total protein content and the low lipid content. The results for the bioactive compounds were high, proving the functional claim of the fermentate. Probiotic viability during 40 days of storage resulted in the decay of viability to free cells. However, for encapsulated probiotics, survival remained constant. The fermented vegetable drink with free cells showed higher acidification and lower pH during storage. The antimicrobial activity demonstrated high efficiency, proving the antagonism against gram-positive and gram-negative pathogenic strains, highlighting the efficacy against Enterococcus faecalis, which is considered resistant to many antibiotics. In this way, survival and the addition of probiotics in plant-based fermented beverages is possible.