Modelling the isothermal degradation kinetics of metrafenone and mepanipyrim in a grape juice analog

Food Res Int. 2018 Jun:108:339-346. doi: 10.1016/j.foodres.2018.03.058. Epub 2018 Mar 24.

Abstract

Five photodegradation products of metrafenone (MTF) and six of mepanipyrim (MEP) were identified in synthetic grape juice at 25 °C and the structures of the main reaction products established. The degradation of MTF and MEP was modelled by using three different strategies involving monitoring (a) the disappearance of the parent compound, (b) the conversion of the parent compound into its main structurally related reaction products and (c) the degradation of the parent compound to all intermediates and degradation end-products. The kinetic coefficients of degradation for these fungicides were determined and the corresponding half-lives found to be 20.8 h for MFT and 10.1 h for MEP. The proposed models afford reasonably accurate interpretation of the experimental data. Based on the results, modelling the kinetics of disappearance of the parent compound by itself does not ensure the best fit of the degradation behaviour of the fungicides.

Keywords: Degradation; Fungicide, metrafenone; Grape juice analog; Mepanipyrim; Modelling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzophenones / analysis*
  • Benzophenones / radiation effects
  • Food Analysis / methods*
  • Fruit and Vegetable Juices / analysis*
  • Fungicides, Industrial / analysis*
  • Fungicides, Industrial / radiation effects
  • Hydrogen-Ion Concentration
  • Hydrolysis
  • Kinetics
  • Models, Theoretical
  • Photolysis
  • Pyrimidines / analysis*
  • Pyrimidines / radiation effects
  • Temperature
  • Vitis*

Substances

  • Benzophenones
  • Fungicides, Industrial
  • Pyrimidines
  • mepanipyrim
  • metrafenone