Parameter estimation for respiration rate of dragon fruit as a function of gas composition and temperature

Controlled atmosphere or modified atmosphere packaging are clean and potentially effective techniques to extend the storage life of dragon fruit (Hylocereus undatus). Application of these techniques requires thorough knowledge about the fruit respiration rate. To this end, this study aims to model the respiration rate as a function of O2 and CO2 level, and temperature, using Michaelis-Menten kinetics and Arrhenius’ law. Dragon fruit were incubated in closed containers with different initial O2 concentrations (5-21%), initial CO2 concentrations (0-10%), and temperatures (2-35°C). A mathematical model based on Michaelis-Mentel kinetics, Arrhenius’ law, and Boltzmann distribution function was used to describe respiration rate as a function of temperature, O2, and CO2 concentration. Data on gas concentration was used to estimate the model parameters, based on the least square principle. The combined Arrhenius-Boltzmann equation was able to describe the reduced increase in respiration rate at high temperature. The estimated model could describe the dragon fruit respiration rate accounting for 98% of the data variance. The estimated parameter showed that CO2 had an uncompetitive inhibition on the respiration. O2 concentration significantly affected both respiration and fermentation. These results will be useful for further studies on the application of controlled or modified atmosphere on dragon fruit quality.

Phuc Le Ho won an ISHS Young Minds Award for the best oral presentation at the VI International Symposium on Applications of Modelling as an Innovative Technology in the Horticultural Supply Chain - Model-IT 2019 in Italy in June 2019.

Acknowledgment
The work was performed in the framework of a PhD performed at both BIOSYST-MeBioS, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium under the supervision of M.L.A.T.M. Hertog and B.M. Nicolaï, and at Faculty of Food Science and Technology, Vietnam National University of Agriculture, Hanoi, Vietnam under the supervision of Q.T. Nguyen and D.T. Tran.
Phuc Le Ho, e-mail: phuc.hole@kuleuven.be

The article is available in Chronica Horticulturae