Comparative Evaluation of Bioactive Potentials in Functional Tea Infusion of Fermented and Non-fermented Centella asiatica Blended with Ginger and Green Tea

Abstract

Aim: To develop and evaluate functional tea infusions from fermented and non-fermented Centella asiatica leaves blended with ginger and green tea, and to assess their antioxidant, phenolic, flavonoid contents, and sensory qualities. Study Design: Comparative experimental study of fermented vs. non-fermented formulations of herbal tea blends. Place and Duration of Study: College of Agricultural Engineering and Post-Harvest Technology, Ranipool (Sikkim), and College of Food Technology, Imphal (Manipur). Duration: 6 months. Methodology: Fresh C. asiatica leaves and ginger rhizomes were collected, shade-dried, fermented (24 and 30 °C; 90-98% RH) for fermented samples, tray-dried at 60°C, ground, and blended with green tea in varying ratios (70–90% C. asiatica leaves, 5–15% ginger, 5–15% green tea). Bioactive analysis was done for Antioxidant activity by DPPH assay (mg AAE/tea sachet), Total phenolics by Folin–Ciocalteu method (mg GAE/tea sachet), Total flavonoids by aluminium chloride colorimetry (mg QE/tea sachet) and sensory evaluation by 9-point hedonic scale with 10 panelists for color, aroma, taste, mouthfeel, and acceptability. Results: Non-fermented formulations showed higher antioxidant activity, phenolic, and flavonoid contents than fermented ones. The best performing formulation was the non-fermented sample 2a (22.09 mg AAE, 13.59 mg GAE, 10.31 mg QE/tea sachet) but the fermented sample 1a had good antioxidant activity (18.16 mg AAE) and was most preferred in sensory evaluation for color, aroma, and overall acceptability. The fermentation slightly reduced bioactive content but improved sensory qualities. Conclusion: Non-fermented C. asiatica tea blends retain more bioactive compounds and antioxidant activity, making them potent functional beverages. Fermented teas, though lower in bioactive content, scored higher in sensory appeal. Blending C. asiatica with ginger and green tea provides a balanced functional tea with both health benefits and consumer acceptability.