Molecular docking of Citric Acid And Ascorbic Acid with Polyphenol Oxydase Enzymes as Browning Inhibition in Apples (Malus sylvestris Mill.)
Tifa Nur Jannah, Bambang Dwi Argo, Yusuf Wibisono

Universitas Brawijaya

Abstract

The molecular docking method is a computational process used to predict the bond orientation between a ligand and a receptor. Molecular docking is performed to find a ligand that has a geometric and energetic fit to a protein site. The molecular docking process aims to determine the interaction between the ligand and the active site of the protein and to analyze the binding affinity, inhibition constant and geometric performance. The lowest inhibition constant and binding affinity values indicate a better and more stable bond form. An increasingly stable bond indicates that the acid (ligand) used is a good and correct ligand. One of the developments in the application of molecular docking is in the agricultural sector, especially in the post-harvest field. In this field, molecular docking can be applied to predict the browning prevention of fruit. Fruits that often experience browning are apples. Apples are fruits that often experience enzymatic browning reactions, namely the reaction of changing the color of the fruit to brown. The enzymatic browning reaction that occurs in apples occurs due to the presence of the polyphenol oxidase (PPO) enzyme which is oxidized by oxygen. The browning process can be inhibited by adding weak acids such as citric acid and ascorbic acid. The browning prevention mechanism can be seen by the molecular method of docking. From the results of the molecular docking performed, it can be concluded that citric acid is a good compound to be used to prevent the browning process in apples with a binding affinity value of -4.18 kcal/mol and an inhibition constant of 0.87 mM.

Keywords: Molecular docking, Citric Acid, Ascorbic Acid, Browning in Apples

Topic: Food biotechnology and bioprocess engineering