"Preservative effect on shelf stability of wine produced from zobo calyces (Hibiscus Sabdarifa) using sodium benzoate:- Ukagha Lilian C

ABSTRACT

This study was aimed at detennining the shelf stability of zobo wine using sodium benzoate. Zoba wine was produced by fermentation of the must using brewer's yeast, Saccharomyces cerevisiae at 28C for a total of 28 days with addition of sodium benzoate (0.5% w/v) and stored for 21 days. The sample and a red wine from grape (oster wine) were analyzed for their physicochemical, microbial and sensory qualities. The results obtained revealed that the physicochemical properties ranged from 5.50 to 6.45, 0.99 to 0.99, 114 to 487 mg/l, 67.50 to 78.50 g/l00ml, 21.00 to 40.50%, 0.28 to 0.31 nm, 13.85 to 76.45 mg/I, 0.50 to 0.69 g/100 ml and 6.61 to 10.04 % for pH, specific gravity, total dissolved solids, total titratable acidity, dry matter, colour intensity, phenol content, total solids and alcohol content, and total solids. In as much as red wine from grapes was higher in the physicochemical properties pH, phenol content, total solids and alcohol content; zobo wine showed higher values in total dissolved solids, total titratable acidity, dry matter and colour intensity. From microbial analysis, no significant bacteria growth was isolated from the samples, although lower in zobo wine. Also, no fungal or colifonn growth was observed. The zobo wine was of comparable microbial quality with the red wine from grapes possibly due to presence of sodium benzoate generally used as preservative in beverages. Sensory evaluation indicated higher acceptance of zobo wine than the red wine from grapes (oster wine). The sensory attributes ranged from 6.90 to 7.65, 5.80 to 7.00, 6.15 to 7.05, 5.85 to 7.05, 5.25 to 7.20 and 6.10 to 7.75 for colour, appearance, clarity, taste, flavour, mouth-feel and general acceptability respectively when evaluated on a 9- point hedonic scale. Although zobo (Hibiscus sabdariffa) extracts are readily contaminated by spoilage microbes, it can be used in the production of shelf stable wine with addition of sodium benzoate and could favourably compete with imported wines.