Accumulation of betacyanin in Hylocereus undatus rind: Pigment stability analysis and its role in xanthine oxidase inhibition

Abstract

Background: Betalain pigments are water soluble natural pigments that contain nitrogen. Betacyanin have been reported to possess several biological properties Method: In the present work, the pigment from the rind of Hylocereus undatus was analyzed for its stability upon elevated temperature, pH, time, light period, and metal ions. Further, the effect of betacyanin pigment on xanthine oxidase enzyme inhibition was studied. Further to retain the betacyanin stability, encapsulation with different encapsulating agents was assessed Results: It was observed that betacyanin pigment was evenly distributed throughout the cells of Hylocereus undatus rind, which was intact in the vacuole. The betacyanin content present in the rind was estimated to be 95±0.873 mg/g fresh weight of peel. The pigment extract was stable upon treatment with ascorbic acid and citric. Betacyanin inhibited xanthine oxidase activity with an IC50 of 9 mM. Kinetics study depicts competitive inhibition mode. Betacyanin quenched the fluorescence intensities of XO, proving its interaction with the amino acid residues of XO. Docking analysis proved a higher binding affinity of betacyanin in the active site residues of XO supported by simulation studies. Starch encapsulation showed greater efficiency in stabilizing betacyanin content. Conclusion: Betacyanin pigment was extracted from Hylocereus undatus rind. Betacyanin thus serves as a xanthine oxidase inhibitor preventing Uric acid elevated diseases.

Keywords

• Hylocereus undatus
• Betacyanin
• Uric acid
• Xanthine oxidase
• Competitive
• Static