Abstract: The microbial and nutritional quality of laboratory produced Zobo drink (obtained from aqueous extract of dried calyces of Hibiscus sabdariffa) was investigated. The samples were subjected to pasteurization (at 70°C for 25 min) alone and with sodium benzoate (0.1%) in combination with pasteurization. Storage stability at room temperature (28±2°C) of aseptically packaged sachets of the beverage in 50 mL was assessed using physico-chemical parameters (loss in vitamin C content, changes in pH and titratable acidity) and microbial changes. The proximate composition of Zobo drink was 88.88% water, 0.046% protein, 0.15% fat, 0.61% crude fibre, 0.21% ash and 10.64% carbohydrate. These values did not change significantly (p>0.05) with respect to treatment methods nor storage time. However, vitamin C content of the beverage 1,105.88 mg 100 mL in the control samples decreased by 53.4 and 61.46% due to pasteurization and sodium-benzoate plus pasteurization respectively. The total plate count of the unpreserved beverage (control) decreased from 1.2×105 cfu mL 1 to 5.0×103 and 1.0×103 cfu mL 1 when subjected to pasteurization and to a combination of sodium benzoate plus pasteurization, respectively. The two methods were both effective in eliminating E. coli and Staplyloccus aureus in the beverage. Bacillus sp., Lactobacillus sp., Saccharomyces, cerevisiae, Mucor sp. and Aspergillus niger were found in association with progressive spoilage [detected in acid- and alcohol production] in the beverage. The shelf life of the beverage on storage was 4, 14 and above 40 days for the control, pasteurized only and sodium-benzoate plus pasteurized samples, respectively.
O.J. Egbere , J.C. Anuonye , P.F. Chollom and P.V. Okpara , 2007. Effects of Some Preservation Techniques on the Quality and Storage Stability of Zobo Drink (A Nigerian, Non Alcoholic Beverage from Hibiscus sabdariffa) . Journal of Food Technology, 5: 225-228.