Study on the Correlation between Some Physical and Microbial Quality Characteristics of Peeled Sweet Orange (Citrus sinensis)

Abstract

Background /Aim: The consumption of ready-to-eat fruits such as oranges has increased in recent times. This study assessed the correlation between some physical and microbial quality characteristics of peeled sweet orange (Citrus sinensis) sold in Yenagoa, the capital of Bayelsa State, Nigeria. Methodology: A total of thirty peeled oranges were purchased, three from each location. Standard microbiological methods were applied for the analysis. Results: Results showed that the in situ characteristics and microbiological load of peeled oranges sold in Yenagoa, Nigeria were in the ranges of 1.86 to 3.15 Log CFU/g (total fungi), 1.56 to 2.86 Log CFU/g (total heterotrophic bacteria), 3.14 to – 4.19 (pH), 1.84 to 3.03 ppt (salinity), 3.27 to 5.00 mS/cm (conductivity) and 2.56 to 4.10 ppt (total dissolved solid). There was statistical deviation (p<0.05) for the in situ characteristics only. There was a positive significant association between the total dissolved solids and conductivity, and total heterotrophic bacteria and total fungi. Salinity negatively correlates with total heterotrophic bacteria and total fungi. The microbial isolates found in the samples include Staphylococcus aureus, Escherichia coli, Enterobacter, Bacillus, Proteus, and Micrococcus species, as well as Aspergillus, Penicillium, Mucor, Fusarium, Saccharomyces cerevisiae, and Trichoderma species. Conclusion: However, with improved handling and hygiene levels among orange vendors, the microbial load could be reduced. Furthermore, the study showed that similar factors affected the total dissolved solids, conductivity, total heterotrophic bacteria, and total fungi. While the negative correlations that exists between salinity and total heterotrophic bacteria and total fungi revealed that diverse factors affect their concentrations in the orange.