Microbial Deterioration of Tomato Fruit ( Lycopersicon esculentum ) Sold in Three Popular Markets in Ilorin, Kwara State, Nigeria

Abstract

The economic loss as a result of spoilage and proliferation of microorganisms on tomato fruits with the possible health risks were the justification for this study. One hundred and fifty tomato fruit samples in different stages of spoilage from three different markets in Ilorin, Kwara State, Nigeria were collected within five weeks and the effect of moisture content on each sample and resulting microflora examined. The pH of the samples ranged from 4.90 - 5.40, while the moisture content ranged from 89.10% - 90.70%. The bacteria counts ranged from 4.00 x 106 - 7.50 x 106 cfu/ml, while the fungal counts ranged from 1.60 x 106 - 3.50 x 106 cfu/ml. A total number of sixteen bacteria and eleven fungi including yeasts were associated with the samples. The bacterial isolates included Aeromonas veronii, Bacillus sp., Neisseria sp., Corynebacterium renale, Pseudomonas fluorescens, Micrococcus varians, Moraxella sp., Bacillus polymyxa, Aeromonas hydrophila, Pseudomonas sp., Bacillus megaterium, Corynebacterium ulcerans, Vibrio sp., Proteus mirabilis, Corynebacterium xerosis, and Bacillus brevis while the fungal isolates included Alternaria sp., Botrytis sp., Candida albicans, Candida guilliermondii, Candida tropicalis, Chrysosporium tropicum, Curvularia sp., Doratomyces microsporus, Geotrichum candidum, Saccharomyces cerevisiae, and Rhizopus stolonifer. The high moisture content of the tomato samples provides an enabling environment for proliferation of the microbial load and hence its spoilage and potential to become health risk to human beings. Keywords: Spoilage, proliferation, economic loss, pH and moisture