ANTIMICROBIAL POTENTIAL OF EDIBLE CHITOSAN-STARCH BASED COMPOSITE FILM ON SOME BACTERIA AND FUNGI ISOLATED FROM DETERIORATED EGGPLANT AND TOMATO FRUITS

Abstract

In developing countries like Nigeria, post-harvest loss of fruits and vegetables have been a serious problem as they become unavailable out of season due to poor preservative techniques. The study aimed at evaluating the antimicrobial potency of edible chitosan-starch based composite on some bacteria and fungi isolated from deteriorated eggplant and tomato fruits. The tomato and eggplant fruits were coated using dipping method while the microorganisms were isolated and identified using standard laboratory procedures. The microbial load of deteriorated fruits showed that tomato had the highest total bacterial, fungal, and coliform counts (6.01±0.26 x 104, 2.83±0.07 x 104 and 3.27±0.11 x 104 cfu/g respectively). The bacteria isolated from deteriorated tomato and eggplant were Bacillus megaterium, Staphylococcus. aureus, Escherichia. coli and Klebsiella sp. while fungi were Aspergillus spp, Fusarium spp., Rhizopus spp. and Saccharomyces spp. However, S. aureus and Aspergilus spp. had the highest percentage occurrence (56.52 and 50.00 %, respectively). The zone of inhibition of B. megaterium growth increased with increase in the volume (thickness) of the film with the highest (40 ml) being 30 mm. Coat volumes of 25 and 30 ml showed the highest activity of 15 mm zone of inhibition against Rhizopus spp. The antimicrobial propertis of the film showed activity against the microorganisms except for S. aureus and Aspergilus spp. respectively.