Comparative studies on extraction methods of betalain content and antioxidant activity of biocolorant obtained from Celosia cristata L. flowers

This study was undertaken to investigate the effect of conventional solvent (CSE), microwave assisted (MAE)and ultrasound assisted extraction (UAE) techniques on the pigment yield, betalain content, total phenolic content and in-vitro antioxidant activity of biocolorant extracted from inflorescence of Celosia cristata. The best extraction method was achieved with MAE at t = 45 seconds that gave maximum values for betalain content (167.9±0.24 mg/kg), total phenolic content (TPC) = 46.84±0.26 mg GAE/gm and antioxidant activity, 79.26±0.35%. For MAE_45S, the total extract yield (TEY) achieved was 34.06 ± 0.08%. The in-vitro antioxidant activity of the extracts revealed that MAE exhibited greater antioxidant activities compared to CSE and UAE. FTIR analysis of the extracts confirmed the presence of betalains by identifying the major functional groups. The study suggests, MAE as a promising alternative for extraction of coloured pigment from C. cristata flowers as it reduces extraction time and increases extraction yields of betalain and other phenolic compounds, thereby increasing anti-oxidant properties of the extracts.