Fermentação probiótica : uma estratégia para valorização de frutas nativas subexploradas

Abstract

Brazil has a wide diversity of native fruits that are rich sources of bioactive compounds, yet they remain underexplored, particularly in the North and Northeast regions of the country. Mangaba (Hancornia speciosa Gomes) and bacaba (Oenocarpus bacaba Mart.) are Brazilian fruits abundant in the Northeast and North regions, respectively, and stand out for their nutritional value. They contain bioactive compounds with potential health-promoting properties. Due to their seasonality and high perishability, these fruits are mainly consumed locally in the form of fruit pulps and remain undervalued. In this context, this thesis was divided into five stages, including two experimental phases. These phases evaluated the technological parameters (pH, total soluble solids, and titratable acidity) and functional aspects (probiotic viability and bioaccessibility) during 48 hours of fermentation and refrigerated storage of mangaba and bacaba pulps inoculated with Lacticaseibacillus casei (LC1) and Lactobacillus acidophilus (LA-05). Additionally, the contents of sugars, organic acids, phenolic compounds, and volatile composition were analyzed in the mangaba pulp over 48 hours of fermentation and storage, and the contents of sugars, organic acids, and phenolic compounds in the bacaba pulp were analyzed during 48 hours of fermentation. Next, the sensory profile of the fermented mangaba pulp was determined using the Preferred Attribute Elicitation (PAE) methodology. Finally, the prebiotic potential of the fermented mangaba and bacaba pulps was evaluated using in vitro colonic fermentation systems inoculated with the gut microbiota of vegan and healthy adults, respectively, through 16S rRNA gene sequencing. The results demonstrated that mangaba and bacaba pulps are suitable substrates to maintain probiotic viability at counts ≥7 log CFU/g and to protect probiotics during exposure to simulated gastrointestinal conditions, ensuring their viability in the intestinal fraction. The probiotic fermented pulps of mangaba and bacaba showed higher concentrations of organic acids, including lactic and propionic acids, and phenolic compounds such as trans-resveratrol, procyanidin B1 and B2, epicatechin, and others. Probiotic fermentation enhanced the bioaccessibility of epicatechin, procyanidin B1, kaempferol 3-glucoside, and caffeic acid in mangaba pulp, and of procyanidin B1 and B2, trans-resveratrol, cis-resveratrol, catechin, epicatechin, and myricetin in bacaba pulp, when compared to the non-fermented pulps. Fermented mangaba pulp increased the relative abundance of Dorea, Romboutsia, and Faecalibacterium, while fermented bacaba pulp increased the abundance of Acidaminococcales, Enterobacterales, and Lactobacillales—microbial groups associated with the production of health-promoting metabolites such as butyrate, acetate, and propionate. Fermented fruit pulps also positively influenced microbial diversity indices, resulting in a balanced and functional gut microbiota. Sensory evaluation of fermented mangaba pulp revealed probiotic viability over 28 days, stability of bioaccessible phenolic compounds, antioxidant activity, and maintenance of quality parameters. The fermented mangaba pulp received higher scores than the non-fermented version for sensory attributes such as color, brightness, freshness, and aroma throughout the storage period, supporting the development of a new functional product.