Isolation and Characterization of Yeasts and Lactic Acid Bacteria from Spontaneously Fermenting Pulp of Sorting Rejects of Kent and Brooks Mango Varieties

Kent and Brooks mango varieties are of major nutritional and economic importance to local populations. However, these fruits are highly susceptible to fermentation, leading to significant post-harvest losses. The objective of this study was to valorize sorting rejects of these mango varieties collected from two processing units in Korhogo (Côte d’Ivoire) through isolation of fermentative microorganisms from their pulps. After ripening, fermentative microorganisms (lactic acid bacteria and yeasts) were enumerated and characterized every three days over a nine-day period using specific culture media and standard microbiological techniques. Enumeration results revealed presence of lactic acid bacteria exclusively in Brooks variety, with microbial loads increasing up to day 6 (from 4.96 to 7.66 log CFU/g) before becoming undetectable from day 9 onwards. In contrast, yeasts were observed only in Kent variety, with a decrease in counts from day 0 to day 3 (from 4.97 to 3.57 log CFU/g), followed by complete disappearance by day 6. Furthermore, the characterization of the isolated fermentative microorganisms yielded a total of 45 lactic acid bacteria isolates and 30 yeast isolates from the pulps of Brooks and Kent mangoes, respectively. Characterization of lactic acid bacteria revealed 36 coccobacilli, 5 cocci, and 4 bacilli. Yeast isolates exhibited an oval morphology, with unipolar and multipolar budding observed as modes of reproduction. This study demonstrates that mango sorting rejects of Kent and Brooks varieties constitute a valuable source of fermentative microorganisms, including lactic acid bacteria and yeasts. The diversity and dynamics of these microorganisms during spontaneous fermentation highlight their potential for biotechnological applications, particularly in development of starter cultures. The isolation and characterization of these microorganisms provide a scientific basis for the valorization of mango sorting rejects, thereby contributing to the reduction of post-harvest.