Abstract

Various types of highly valued food and medicinal products are produced from Hibiscussabdariffa in different parts of the world. In Nigeria, the calyces of this plant are processed into a refreshing non-alcoholic beverage known as zobo. In this work, zobodrink was prepared using hot water extraction method and the juice obtained was blended separately with aqueous extracts of ginger and garlic. Physico-chemical, microbiological and sensory properties of the various blends of zobo were investigated. The results of this study showed that the zobo samples contained different concentrations of ascorbic acid which ranged between 22.5 and 35.8 mg/100 g. The pH ranged between 3.94 and 7.67, while the total sugar was between 2.5 and 3.56 mg/100 g. The samples also contained varying concentrations of Mg²⁺, K⁺, Ca²⁺, Fe²⁺, Na⁺ and Zn²⁺. The total viable counts of the samples during storage showed that the microbial loads increased steadily and ranged between 1.2 × 10³ and 3.7 × 10⁷ (CFU/ml). The samples containing ginger and garlic had the lowest microbial count of 2.7 × 10⁴ CFU/ml on the seventh day of storage, while the sample containing no extract had the highest microbial load of 3.7 × 10⁷ CFU/ml within the same period of time. The sensory attributes of zobo beverage degenerate during the seven days of storage. However, the samples containing ginger and/or garlic were better rated in terms of the parameter tested. The results of this study indicate that incorporation of ginger and garlic extracts into zobo drink could be an effective means of improving quality attributes of this drink.

Key words: Hibiscus sabdariffa, sensory properties, zobo drink, microbial count.