Microbial contamination and polyethylene packaging of some fruits and vegetables retailed at Akure and Ado Ekiti, South Western Nigeria

Abstract

This study was carried out to reveal microbial contaminants on some selected ready-to-eat fruits and vegetables (eggplant, apple, tiger nut, bitter kola, cola nut, date and carrot) vended at motor parks, busy roads and local markets in Akure and Ado Ekiti metropolis (South Western Nigeria). It also evaluated the effectiveness of polyethylene packaging in controlling microbial contamination of these foods using product shelf life indices as criteria. Bacteria contaminants were isolated from samples and characterized using standard microbiological methods. Samples were also disinfected and stored in 1, 4, 7, 10 and 13 µm thick polyethylene bags at 29°C and 84% RH for 10 days. Result showed that cola nut, carrot, eggplants and tiger nut sold at all wholesale and retail points studied (100%) were contaminated. Apple and bitter kola at wholesale points were however free of microbial contaminants as was also observed for apple at two of its retail points (20%) and bitter kola at only one of the ten retail points studied (10%). Staphylococcus spp. was the most frequently isolated, followed by Klebsiela spp., others include Proteus, Bacillus, Pseudomonas, Serratia and Streptococcus species. Storage of bitter kola, eggplant and date in 7, 10 and 13 µm thick polyethylene films extended shelf life for ten days in ambient temperature of the tropics, while 1 and 4 µm were best for carrot under the same condition. Contrariwise, cola nuts stored in the different polyethylene thicknesses studied became discoloured during storage. Packaging of bitter kola, eggplant, date and carrot in polyethylene prevented microbial contamination and extended shelf life during retailing.   Key words: Ready-to-eat, microbial contaminants, polyethylene bags, storage.