Antimicrobial Effect of Lime Juice Treatment on the Shelf-Life of Zobo Drink

Abstract

Zobo drink is an indigenous non-alcoholic drink made from hot water roselle calyces of Hibiscus sabdariffa. The drink has gained wide acceptance, as it is consumed by several millions of people from different socio-economic classes and background in West African sub-region. The greatest limitation for large-scale production of zobo drinks is the rapid deterioration of the drink. Its shelf-life is approximately 24 hours after production, if not refrigerated. The effect of lime juice on the microorganisms associated with zobo drink was investigated. Zobo drink was prepared by maintaining the appropriate hygienic standards. Microbiological analysis was carried out on the prepared sample, before treatment with lime juice, to determine its effect on the microbial quality of the drink. The mean total coliform count from the prepared sample was 0.1 x 10-4 cfu/mL, aerobic bacterial count was 0.2 x10-4 cfu/mL and the fungal count was 0.4 x 10-4 cfu/mL. Microorganisms isolated from the prepared sample include Staphylococcus spp, Lactobacillus spp, Bacillus spp and Penicillium spp. The antimicrobial effect of the lime juice on the different isolates showed significant zone of inhibition even at 6.25% concentration. The total coliform and aerobic bacterial count generally decreased in value and showed no growth at 50-100% concentrations of lime juice for 3 days and 75-100% concentrations for 5 days. The findings from this study showed that lime juice can be used as natural preservative to prolong the shelf- life of zobo drink for a period 5 days under normal room temperature.