Comparative evaluation of anthocyanin pigment yield and its attributes from Butterfly pea (Clitorea ternatea L.) flowers as prospective food colorant using different extraction methods

Amongst natural colors, blue is probably the most difficult natural color to work with since the sources are scarce; the pigment color is dependant on pH and it is the least stable. Clitoria ternatea L. produces edible flowers that are rich sources of brilliant blue-colored anthocyanins called ''ternatins''. The present study was conducted with the objective of coming up with an efficient, low-cost, and eco-friendly method of anthocyanin pigment extraction from Butterfly pea flowers with the perspective of food application. Amongst different extraction methods used, aqueous method gave significantly higher TMAC (7925.29±36.07 mg/l) and per cent polymeric color (25.28±1.14 %), whereas higher recovery (73.17±1.76 %), antioxidant activity viz. DPPH (3.49±0.59 µl/ml), FRAP (3.99±1.10 µl/ml) and ABTS ((2.42±0.01 µl/ml), total phenolics (29.78±1.79 mgGAE/100 g), total flavonoids (20.13±0.40 mgQE/100 g), instrumental color values indicating brilliant-blue color viz. L* (27.74±0.73), a* (46.90±0.77), b* (-63.25±0.13) and chroma (78.74±0.38) hue angle (306.56±0.50) were observed in microwave assisted extraction (MAE) method. LC-MS/MS analysis of the pigment concentrate resulted in the detection of myristyl sulphate and DL-malic acid, having pharmacological significance. The proposed extraction method is the safest, economic, convenient, and eco-friendly solution for commercial anthocyanin extraction that can be up-scaled as a green-extraction technique at the industrial level.