Measurement and Modeling of Respiration Rate of Tomato (Cultivar Roma) for Modified Atmosphere Storage

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.

Mathematical modelling of diffusion channel length to maintain steady-state oxygen concentration for controlled atmosphere storage of tomato

“…The respiration rate of tomato was obtained through the closed respiration system experiments at 10°C. Kandasamy et al [21] reported detailed experiment as well as calculation procedures.…”

“…Therefore, the respiration rate of tomato was considered mainly as a function of O 2 concentration. [21] The inhibition parameter K 3 , calculated as the rate of CO 2 evolution, was inversely related to temperature, whereas the one calculated as the rate of O 2 consumption was directly proportional to the temperature. This is because the rate of CO 2 evolution during the respiration process is not same as the rate of O 2 consumption.…”

“…The parameter K 3 was negligible in either case which nullifies the effect of changing CO 2 concentration on the respiration rate. [21] As the inhibition constant K 3 for CO 2 concentration in Eq. ( 9) was negligible, the model was modified mainly as a function of O 2 concentration (Eq.…”

“…The following model was adopted to predict the respiration rate of tomato as a function of O 2 and CO 2 concentration: [21] r…”

“…The constant K 3 was negligible in either case, which nullifies the effect of changing CO 2 concentration on the respiration rate. [21] Hence, the respiration rate was assumed only as a function of O 2 concentration as follows:…”