Quality of Novel Herbal Tea Prepared from Garden Nightshade (Solanum nigrum) Leaves

Growing interest in herbal teas has driven demand for blends with medicinal benefits. This study developed functional teas by substituting commercial black tea (CBT) with nightshade leaves powder (NGLP) at 25%, 50%, 75%, and 100% levels. The impact on chemical composition, antioxidant activity, physicochemical properties, and sensory qualities was assessed. Analyses included proximate composition, total phenolics, flavonoids, antioxidant capacity (DPPH assay), pH, titratable acidity, total soluble solids, color parameters, catechin, caffeine, and sensory evaluation. Increasing NGLP proportions significantly raised ether extract, ash, crude fiber, phenolics, and flavonoids while reducing protein, carbohydrates, caffeine, and catechins. The highest antioxidant activity (67.54%) was recorded at 100% NGLP compared to 49.45% in CBT. Titratable acidity ranged between 0.195–0.210 g/100 mL. Color parameters (L*, a*, b*) declined with higher NGLP substitution, darkening the tea. Sensory evaluation showed all blends were acceptable, though CBT and the 25% NGLP blend scored highest in preference. Replacing CBT with up to 50% NGLP enhances nutritional value and antioxidant properties without compromising taste and acceptability. Further research is encouraged to investigate the therapeutic potential of nightshade-based teas, particularly for antioxidant and dietary fiber enrichment.