Microbial Changes During the Fermentation of Aerial Potato (Discorea bulbifera Linn)

Abstract

Dioscorea bulbifera is one of the under-utilized tubers in Nigeria both for food and medical purposes. Microbial changes during the fermentation of aerial potato after being subjected to different treatment were monitored using standard methods, the changes in microbial load and type of microorganisms was reported. It was observed that unpeeled backslopping fermented samples had the highest total viable bacterial count (7.06±0.05 x 105 cfu/g), lactic acid bacterial count (67.74±1.17 x 107 cfu/g) and fungal count (0.81±0.16 x 106 sfu/g), while total viable bacterial, LAB and fungal in peeled samples were 30.40±2.00 x 1010 cfu/g, 298.17±2.36 x 107 cfu/g and 133.30±0.15 x 106 sfu/g at 120 hour of fermentation respectively. Some of the bacteria isolated include Shigella flexneri, Escherichia coli, Staphylococcus aureus, Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus plantarum, Lactococcus lactis, while the fungal isolates were Fusarium oxysporum, Geomyces pannorum, Geotrichum candidum, Penicillium brevicompactum, Penicillium corylophilum, Saccharomyces cerevisiae, Candida tropicalis and others species. The treatment methods employed had a significant effects on the microbial load of fermented aerial potato. The fermentation methods employed have significant effects on the microbial load and type of microorganisms in the fermented aerial potato. Fermentation can be used as a food processing method to eliminate unwanted microorganisms in fermented food, which will enhance the food shelf life.