Cerrado fruits residues under probiotic strains fermentation: prebiotic properties and polyamine production

Abstract

Background. Limited information exists on the chemical composition and prebiotic properties of cajuzinho- -do-cerrado (Anacardium humile) and marmelo-do-cerrado (Alibertia sessilis) residues, which are typically discarded during fruit processing. This study characterizes these residues and investigates their prebiotic potential. Material and methods. The antioxidant capacity, phenolic compounds, functional properties, and prebiotic potential of the residues were evaluated. Methanolic extracts were analyzed using spectrophotometric methods (DPPH, Folin-Ciocalteu) and HPLC. Water and oil holding capacities were measured by centrifugation. Three probiotic strains and two E. coli strains were cultivated in modified media using the residues as carbon sources. Cell viability was assessed by agar plate counts. Metabolic activity was monitored by measuring pH, sugar and organic acid concentrations, and bioactive amine production using HPLC. These analyses were designed to evaluate functional characteristics of the residues, including antioxidant capacity, water and oil holding abilities, and their ability to support probiotic growth and metabolism, thereby assessing prebiotic potential. Results. CR and MR showed high levels of total dietary fiber and protein. Considerable concentrations of total phenolic compounds were detected; gallic acid and coniferaldehyde were quantified in CR, while p-coumaric acid and luteolin were quantified in MR. Cultivation of Lactobacillus acidophilus LA-05, Lacticaseibacillus casei L-26, and Bifidobacterium animalis subsp. lactis BB-12 in media containing CR and MR promoted their growth – especially L. casei – along with a decrease in pH and significant production of organic acids, such as lactic and acetic acids. Fermentation of these residues also led to polyamine production, including spermidine, indicating intense fermentative metabolic activity by these microorganisms. Conclusion. The residues display characteristics indicative of prebiotic potential and may confer human health benefits. They could also be considered as functional ingredients for the formulation of new food products.