Screening of natural spices for improving the microbiological, nutritional and organoleptic qualities of the Zobo drink

  • OE Ezearigo
  • PO Adeniji
  • F Ayoade
Keywords: Zobo, shelf life, natural spices


Objective: The study aimed at standardizing the Zobo -making process and improving its nutritional, organoleptic and microbial qualities thereby increasing its shelf life using natural spices, 4 natural spices namely, ginger, garlic, cinnamon and nutmeg.
Methodology and Results: At 1%, w/v concentration per spice, a chemical preservative, sodium benzoate at different concentrations (1%, 0.1% and 0.01%) and control to which no preservative was added were stored at ambient temperature and control samples were stored in the refrigerator at 4°C for 28 days. Samples were drawn periodically after preparation for microbiological analyses. Serially diluted samples were inoculated in  duplicates onto Nutrient Agar (NA) and Potato dextrose agar (PDA) for bacteria and fungi respectively, the NA plates were incubated at 370C for 18-24 hours and the PDA plates at 300C for 3-6 days before reading the plates. The spoilage organisms were identified using standard cultural, staining and biochemical techniques. The spoilage bacterial organisms were identified as Micrococcus luteus, Corynebacterium xerosis, Bacillus sphaericus, Veillonella spp, Aeromonas veronii, Pseudomonas spp,
Corynebacterium kutscheri, Bacillus marinus, Bacillus megaterium and Bacillus pumilus while the fungal spoilage organisms identified from the Zobo samples include Aspergillus niger, A flavus, A. fumigatus and
Geotrichum spp.
Conclusion and application of study: The natural spices were more effective than refrigeration in delaying microbial deterioration of Zobo. Nutmeg was the most effective. Moreover, the results showed that Zobo will spoil after 12 days, and that treatment of Zobo with nutmeg is most effective (critical difference=0.058; pC0.05) at extending the shelf life of Zobo while maintaining the nutritional and organoleptic properties of the drink.
Application of results: The study shows the possibility of large-scale production of Zobo using treatment with nutmeg as a safe, low-cost means of preservation.

Key words: Zobo, shelf life, natural spices


Journal Identifiers

eISSN: 1997-5902