ANTIOXIDANT ACTIVITY OF SEVERAL EXTRACTS FROM FIVE HERBAL TEA PLANTS

• Main Author: Kurniasari, Purwa
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/79999
• Institution: Institut Teknologi Bandung

Background and purpose: Herbal teas and green teas are both widely consumed worldwide due to perceived health benefits and high antioxidant content. Some herbal plants that have been consumed as herbal tea include roselle flowers (Hibiscus sabdariffa), sappan heartwoods (Caesalpinia sappan), telang flowers (Clitoria ternatea), and tea leaves (Camellia sinensis). Numerous studies were conducted to investigate the phytochemical compounds present in them. However, research on the antioxidant activity of diverse extracts was limited. The purpose of this study was to examine the antioxidant activity of different extracts based on the polarity group and their correlation with phenol and flavonoid. Method: Samples were extracted by reflux using increasing polarity solvent (n-hexane, ethyl acetate, ethanol) sequentially and direct extraction using ethanol solvent. The total phenolic content (TPC) was determined using Folin-Ciocalteu reagent. The total flavonoid content (TFC) was investigated using colorimetric assay with AlCl3. The antioxidant activities were determined using 2,2-difenil-1-pikrilhidrazil (DPPH), Cupric Ion Reducing Antioxidant Capacity (CUPRAC), and Ferric Reducing Antioxidant Power (FRAP). The correlation between TPC and TFC on antioxidant activities were analyzed by Pearson’s method. Results: The highest TPC was found in ethyl acetate extract of sappan heartwood (C. sappan) (76.291 ± 1.495 g GAE/100 g) and the highest TFC was given by n-hexane extract of sappan heartwood (C. sappan) (5.092 ± 0.202 g QE/100 g. According to the result, ethyl acetate extract of sappan heartwood (C. sappan) and ethanolic extract of tea leaves (C. sinensis) had superior antioxidant activity among all samples. TPC and TFC were positively correlated with antioxidant activity. Conclusion: In general, ethyl acetate extracts of red and purple rosella flowers, telang flowers, and secang flowers had higher antioxidant activity compared to n-hexane extract and ethanol extract. Ethanol extract of green tea leaves had higher antioxidant activity compared to nhexane extract and ethyl acetate extract. Phenol and flavonoid compounds contributed to the antioxidant activity.