NUTRITIONAL, PHYTOCHEMICAL AND SENSORY PROPERTIES OF ZOBO DRINK WITH KOLANUT EXTRACTS
Abstract
ABSTRACT
Zobo drink, a popular Nigerian beverage produced from Hibiscus sabdariffa calyces, is often consumed for its refreshing and health-promoting properties. However, the incorporation of kolanut extracts from different varieties may influence its nutritional, chemical, microbial, and sensory characteristics. This study evaluated the proximate composition, mineral content, caffeine and tannin levels, microbial load, and sensory attributes of zobo drinks prepared from zobo calyces fortified with extracts from four kolanut varieties (Gbanja pupa, Gbanja funfun, Orogbo, and Abata). Five formulations were produced: Sample ZC (Conventional Zobo), Sample ZO (Zobo + Orogbo), Sample ZA (Zobo + Abata), Sample ZGP (Zobo + Gbanja pupa), and Sample ZGF (Zobo + Gbanja funfun). Standard analytical methods were used to determine proximate and mineral compositions, caffeine and tannin contents, microbial load, and sensory evaluation using a 9-point hedonic scale. Proximate composition ranged as follows: moisture 81.29–89.50%, protein 0.00–0.86%, fat 0.04–0.17%, fibre 0.00–0.13%, ash 0.30–0.59%, and carbohydrate 9.94–17.03%. Mineral content showed variation among formulations: iron 0.31–0.70 mg/100 g, calcium 24.58–88.44 mg/100 g, and potassium 5.60–10.67 mg/100 g, with Sample ZGP recording the highest calcium and iron contents. pH ranged between 4.83 and 4.91. Microbial load ranged from 1.11×10² to 1.67×10² cfu/ml. Tannin content was 50.76–121.75 mg/100 g, while caffeine ranged from 4.99 to 13.41 mg/100 ml, with the highest in Sample ZGF. Sensory scores were generally high across samples: taste 7.80–8.70, colour 7.80–8.70, flavour 7.40–8.60, and overall acceptability 7.50–8.80, with the conventional zobo (Sample ZC) having the highest overall preference. The study concluded that kolanut incorporation influenced the nutritional, mineral, caffeine, and sensory properties of zobo drinks. Gbanja pupa extract (Sample ZGP) improved mineral composition, while Gbanja funfun (Sample ZGF) contributed higher caffeine levels. All zobo samples were microbiologically safe and organoleptically acceptable, suggesting that kolanut-enriched zobo drinks could serve as functional beverages with distinctive sensory and nutritional characteristics.
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