Title
Unraveling the inhibition mechanism of cyanidin-3-sophoroside on polyphenol oxidase and its effect on enzymatic browning of apples
Author
Hridya Hemachandran, Amrita Anantharaman, Sankari Mohan, Gopalakrishnan Mohan, D. Thirumal Kumar, Diksha Dey, Drishty Kumar, Priyanka Dey, Amrita Choudhury, C. George Priya Doss, Siva Ramamoorthy
Year
2017
Journal
Food Chemistry
Abstract
The hunt for anti-browning agents in the food and agricultural industries aims to minimize nutritional loss and prolong post harvest storage. In the present study, the effect of cyanidin-3-sophoroside (CS) from Garcinia mangostana rind, on polyphenol oxidase (PPO) activity was investigated. The non-competitive inhibition mode of CS was determined by Lineweaver Burk plot. CS forms a ground-state complex by quenching the intrinsic fluorescence of PPO. The static quenching was temperature-dependent with an activation energy of 4.654 ± 0.1091 kJ mol−1 to withstand the disruption of amino acid residues of the enzyme binding site. The enzyme conformational change was validated by 3D fluorescence and CD spectrum. Docking (binding energy −8.124 kcal/mol) and simulation studies confirmed the binding pattern and stability. CS decreased PPO activity and browning index of fresh cut apples and prolonged the shelf life. Thus, CS appears to be a promising anti-browning agent to control enzymatic browning.
Instrument
J-715
Keywords
Circular dichroism, Secondary structure, Ligand binding, Biochemistry, Food science