Analysis of the Microbial Quality of Palm Wine Sold at Orieagu Market, Imo State, Nigeria

Abstract

Background: Palm wine is a spontaneously fermented beverage whose microbial composition may be influenced by tapping, transportation, storage and retail handling. This study evaluated the culturable microbial quality of palm wine sold at Orieagu Market, Ehime Mbano, Imo State, Nigeria. Methods: Eight palm-wine samples obtained from different vendors were transported under cooled conditions and analysed using culture-based microbiological procedures. Serially diluted samples were inoculated on nutrient agar, MacConkey agar and Sabouraud dextrose agar. Microbial isolates were characterised using colony morphology, microscopic characteristics and conventional biochemical tests. Results: Total bacterial counts ranged from 0.5 × 10² to 1.6 × 10² CFU/mL, while the reported fungal counts ranged from 1.0 × 10³ to 2.5 × 10³ CFU/mL. Sample C recorded the highest reported bacterial and fungal counts, whereas Sample G recorded the lowest. Presumptively identified bacterial isolates included Bacillus, Staphylococcus, Streptococcus and Lactobacillus species and Escherichia coli. The fungal isolates were provisionally identified as Aspergillus species, Saccharomyces cerevisiae and Candida tropicalis. Fermentation-associated organisms were recovered together with organisms that may indicate environmental or post-collection contamination. Conclusion: The findings demonstrate the presence of diverse culturable microorganisms in retail palm wine from the study location. Further investigations should include temporal and replicate sampling, validated selective methods, molecular confirmation and direct mycotoxin analysis.