Microbiological examination and Preservative methods of a local beverage drink (Zobo) sold in Anambra State, Nigeria

Umeh, S.O., Okeke, B.C., Okpalla, J., Agu, G.C.


‘Zobo drink’ is a familiar drink consumed by both old and young in Nigeria. This drink is produced in various homes with local methods of preparations. It cannot be stored for a long time without microbial contamination and spoilage. Preservatives had not been added to the beverage drink to prolong its shelf life. In this study, Potassium metabisulphite (K2S2O5) was added as a preservative and various methods of storage employed. Two samples of zobo were prepared and labeled S1 (without preservative) and S2 (with preservative). They were dispensed 30 ml volume in 40 ml containers and closed airtight. The samples were stored on the bench, in the fridge and the last batch pasteurized before refrigerating. Microbial analysis on the first day of preparation showed that the samples were sterile on that day. After 48 hrs, the samples without preservatives show microbial counts. Microbial counts were noticed in all the samples on the bench with preservative on the 10th day. The samples with preservatives pasteurized and refrigerated showed no growth at the end of the study. The method of preparation, pasteurization and refrigeration did not affect the consumer acceptability of the drink. It is therefore advised to add potassium metabisulphite in the preparation of zobo drink after which the drink will be pasteurized and refrigerated to increase its shelf life.

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