PREBIOTIC POTENTIAL OF UMBU-CAJÁ FLOUR IN AN IN VITRO FERMENTATION SYSTEM

The by-products of fruit pulp processing, consisting essentially of peels, seeds, roots, pomace and stones, contain considerable amounts of bioactive molecules. Fibres, the substances most present in these by-products, have been studied due to their prebiotic potential, since they can be fermented by the bacterial population present in the human intestinal microbiota, enabling positive changes in composition and metabolic activity. The aim of this research was to evaluate the prebiotic potential of the flour from the processing of umbu-cajá’s by-product (Spondias spp.) on the bacterial population present in the human intestinal microbiota. The by-product of fruit processing was subjected to drying, simulated in vitro digestion, followed by fermentation with human faecal inoculum. The human faecal inoculum was obtained from the faecal mixture of six healthy donors. For the fermentation process, faecal inoculum (40%), growth medium (40%) and digested by-product (20%) were used, followed by anaerobic incubation at 37°C for 48 hours. During colonic fermentation, pH values were measured, with the bacterial population being then quantified and the prebiotic index assessed. The results showed a positive prebiotic index for the flour (p ≤ 0.05), with an increase in the relative abundance of populations of Lactobacillus /Enterococcus spp, Bifidobacterium spp. and R. albus/R. flavefaciens (p ≤ 0.05), though with a decrease in the population of E. rectal - C. coccoides, while populations of Bacteroides spp./Prevotella spp. showed no significant changes over the fermentation time (p≤0.05). At the same time, there was intense metabolic activity represented by a decrease in pH values and an increase in the production of organic acids in all media and over the 48 hours of fermentation. These results suggest that the flour from the by-product of umbu-cajá processing has the capacity to induce beneficial changes in the composition of the intestinal microbiota, presenting potential prebiotic properties.