Betacyanins extraction from Hylocereus polyrhizus using alcohol/salt-based liquid biphasic partitioning system and antioxidant activity evaluation

ABSTRACT

Betacyanins have gained increasing interest as natural food dye because of their health-promoting effects. This study investigated the betacyanins extraction from peel and flesh of red–purple pitaya using ethanol/K₂HPO₄-based liquid biphasic partitioning system (LBPS) by optimised concentrations of ethanol, K₂HPO₄, NaCl and crude. Overall, the highest values of betacyanins concentration in alcohol-rich top phase (C_t), phase volume ratio (V_r) and partition coefficient (K) of betacyanins that represented an optimum betacyanins extraction from the peel (98.080%, 1.667 and 51.097, respectively) and flesh (96.256%, 2.167 and 25.764, respectively) were achieved. Lastly, conventional solvent extractions, colour characterisation and antioxidant activity evaluation were conducted.

KEYWORDS:

• Antioxidant activity
• betacyanins
• liquid biphasic partitioning system
• red–purple pitaya

Research highlights

• Red–purple pitaya is a good source of betacyanins.

• Ethanol/K₂HPO₄-based LBPS is an effective approach for betacyanins extraction.

• Peel and flesh extract showed the highest C_t at 98.080% and 96.256%, respectively.

• Peel and flesh extract showed different hues and saturations of red colour.

• They retained in a good antioxidant activity.

Acknowledgments

The authors gratefully acknowledge all the funding units.

Declaration of interest

None

Additional information

Funding

This work was supported by the Ministry of Science, Technology and Innovation [grant number MOSTI-02-02-12-SF0256]; CFF-UNMC Doctoral Training Partnership Scholarship Scheme ;Prototype Research Grant Scheme (Malaysia) [grant number PRGS/2/2015/SG05/UNIM/03/1];Fundamental Research Grant Scheme (Malaysia) [grant number FRGS/1/2015/SG05/UNIM/03/1], [grant number FP005-2013B].