Respiratory dynamics of fresh baby corn (Zea mays L.) under modified atmospheres based on enzyme kinetics

The respiratory behaviour of baby corn - whole and end-cut, under different temperatures and gas conditions was evaluated to study its respiratory dynamics based upon enzyme kinetics. The dependence of respiration rate on the O2 and CO2 concentrations has been described assuming the enzyme kinetics model for combined type of inhibition caused by CO2. Various respiratory parameters viz. maximal O2 consumption rate Michaelis-Menten constants, Inhibition constants under the specified environmental conditions of 5, 12.5, 20°C and 75% relative humidity (RH) were estimated using non-linear regression technique. The enzyme kinetics parameters were analyzed according to Arrhenius law to study their temperature dependence. Based upon the overall analysis, it was found that storage temperature had substantial affect on the partial pressures within the closed containers and subsequently the respiration rates. The concentration of O2 inside the container and surrounding temperature had synergistic effect on the rate of respiration and respiratory parameters. Though the inhibition by evolved CO2 was observed to be of combined type, it changed from predominantly competitive at 5°C to predominantly uncompetitive at 12.5 and 20°C. This study can be utilized for design of modified atmosphere packages for storage of fresh and minimally processed baby corn.