Chemical characterization of ethanolic extract of Butterfly pea flower (Clitoria ternatea)

Abstract

Clitoria ternatea, commonly known as Butterfly pea flower or Bunga telang, is a tropical flower and notable as one of the most vital sources of polyphenols with high antioxidant capacity. C. ternatea abundantly produces anthocyanin compounds benefiting natural blue colourants. To date, a blue colourant is the most difficult to obtain since the anthocyanins responsible for this colour is the least stable and easily degraded after extraction. Their stability commonly relies on several operational parameters, such as shifted pH value, high temperature, and light exposure. Apart from colour attributes, anthocyanins have also been identified as a source of functional molecules due to antioxidant activity and beneficial health effects such as anti-cancer, anti-obesity, antimicrobial and more. This study aimed to characterize the chemical constituents of the extractable polyphenols from ethanolic extract of C. ternatea quantitatively. The numerical data were evaluated using the Minitab version 18 statistical method. The chemical profiling, including total phenolic content (TPC), total flavonoid content (TFC), total monomeric anthocyanins (TMA) were determined using standard methods. The antioxidant activity was evaluated using DPPH and ABTS methods. The results showed that the ethanolic extract of C. ternatea had 35.7 mg QE/g of TFC, 102.4 mg GAE/g280nm and 28.8 mg GAE/g750nm of TPC and 2.7 CE/g and 2.9 ME/g of TMA. The total phenolic content of C. ternatea showed a good correlation with the antioxidant activity by the DPPH method when analysed using Pearson correlation and showed an increasing trend of antioxidant power with regards to TPC in both assays. In a nutshell, this study contributes to the knowledge of ethanolic extract of C. ternatea. Future research could consider exploring other extraction methods that could enhance the stability of polyphenols particularly the anthocyanins from degradation such as using surfactants.