Unraveling the inhibition mechanism of cyanidin-3-sophoroside on polyphenol oxidase and its effect on enzymatic browning of apples

Food Chem. 2017 Jul 15:227:102-110. doi: 10.1016/j.foodchem.2017.01.041. Epub 2017 Jan 18.

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±0.1091kJmol-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 -8.124kcal/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.

Keywords: Browning; Cyanidin-3-sophoroside; Garcinia mangostana; Non-competitive; Polyphenol oxidase; Static quenching.

MeSH terms

  • Anthocyanins / chemistry
  • Anthocyanins / metabolism*
  • Catechol Oxidase / chemistry
  • Catechol Oxidase / metabolism*
  • Color
  • Malus / chemistry
  • Malus / enzymology
  • Malus / metabolism*
  • Molecular Docking Simulation
  • Oxidation-Reduction
  • Plant Proteins / chemistry
  • Plant Proteins / metabolism*

Substances

  • Anthocyanins
  • Plant Proteins
  • cyanidin
  • Catechol Oxidase