Isolation, Identification, and Management of Microorganisms Associated with the Spoilage of Ripe Mango Fruit in Dutse, Nigeria

Abstract

This study examined the microbial spoilage of ripe mango fruit (Mangifera indica L.) harvested from Dutse of Jigawa State, Nigeria and the effectiveness of physical, chemical and biological post-harvest management practices. Samples of mango were taken from the local market and farms and analyzed in the lab. The results showed that higher incidence of fungal pathogens, Aspergillus niger (35%) and Penicillium species (30%), were observed followed by yeast (Saccharomyces cerevisiae, 24%) and Pseudomonas aeruginosa (11%). For all the microorganisms isolated, pathogenicity tests showed that the microorganisms had different virulence levels; the most virulent microorganism was A. niger. The use of refrigeration at 10°C was found to be most effective among the management practices tested, resulting in 90% reduction in microbial growth and 10 days shelf life of the fruit. The chemical treatment using 0.1% w/v sodium benzoate also proved to be very effective with a microbial reduction of 85% for a shelf-life extension of 7 days. After 5 days, Modified Atmospheric Packaging (MAP) decreased microbial growth by 80% with an extension of 8 days whereas a dip in 1% (w/v) calcium chloride decreased microbial growth by 75% with an extension of 5 days. Biological agent Bacillus subtilis was effective in suppressing microbial growth by 70% and prolonging shelf life by 6 days, which was considered as a bio-control agent. A significant difference (P < 0.05) was observed between the different management strategies in terms of microbial growth reduction. The results of this study reveal that microbial spoilage is a major problem in mango production in the Dutse region and the series of effective and practical post harvest interventions recommended here can help reduce these losses and enhance food security and livelihood outcomes for farmers in the region.