Nutritional, Antioxidant and Sensory Properties of a Functional Beverage Developed from Guava Leaves and Barley Seeds

The growing demand for functional beverages has led to the exploration of plant-based ingredients with health-promoting properties. This study aimed to formulate and evaluate a natural functional beverage using guava leaves (Psidium guajava), barley seeds (Hordeum vulgare), ginger (Zingiber officinale) and cinnamon (Cinnamomum spp.). Three variations of the beverage were prepared by altering the quantities of guava leaves and barley seeds, while maintaining constant levels of cinnamon, ginger, and water. Sensory evaluation was conducted using a 7-point hedonic scale, and the best-performing variation was selected based on statistical analysis. Nutritional composition, vitamin, mineral content, antioxidant potential and microbial safety of the optimized beverage were assessed using standard AOAC methods and in vitro antioxidant assays (DPPH, ABTS, and FRAP). The results showed that the detox drink was low in calories (12 kcal/100 g) and contained beneficial nutrients including dietary fiber (1.14 g/100 g), potassium (24 mg/100 g), vitamin E (1.7 mg/100 mg) and vitamin K (4.8 mg/100 mg). The beverage also exhibited strong antioxidant activity particularly in the FRAP (2700.2 mg/100 g) and ABTS (2500.7 mg/100 g) assays. One-way ANOVA revealed a significant difference in sensory attributes among the formulations (F = 7.81, p = 0.0093), indicating the influence of ingredient concentration on consumer acceptability. Microbiological evaluation confirmed the product's safety, with negligible counts of aerobic bacteria, yeast, and mold, and the absence of pathogens. Overall, the formulated functional beverage demonstrated promising potential as a safe, palatable, and health-enhancing functional beverage.