Abstract

Experiments were conducted to determine the respiration rate of tomato at 10, 20 and 30°C using closed respiration system. Oxygen depletion and carbon dioxide accumulation in the system containing tomato was monitored. Respiration rate was found to decrease with increasing CO₂ and decreasing O₂ concentration. Michaelis-Menten type model based on enzyme kinetics was evaluated using experimental data generated for predicting the respiration rate. The model parameters that obtained from the respiration rate at different O₂ and CO₂ concentration levels were used to fit the model against the storage temperatures. The fitting was fair (R² = 0.923 to 0.970) when the respiration rate was expressed as O₂ concentation. Since inhibition constant for CO₂ concentration tended towards negetive, the model was modified as a function of O₂ concentration only. The modified model was fitted to the experimental data and showed good agreement (R² = 0.998) with experimentally estimated respiration rate.

Keywords: Carbon dioxide, modeling, oxygen, respiration, temperature, tomato.

Graphical Abstract