MODEL FOR FRESH PRODUCE RESPIRATION IN MODIFIED ATMOSPHERES BASED ON PRINCIPLES OF ENZYME-KINETICS

A respiration model, based on enzyme kinetics, was proposed for predicting respiration rates of fresh produce as a function of O2 and CO2 concentrations. In this model, the dependence of respiration on O2 was assumed to follow a Michaelis-Menten type equation (r = V(m)[O2]/{K(m) + [O2]}), and the effect of CO2 on respiration to follow an uncompetitive inhibition model (r = V(m)[O2]/{K(m) + (1 + [CO2]/K(i)) [O2]}). The model predictions agreed well with published data for a variety of commodities and with experimental data for cut broccoli. Fresh produce respiration rates (O2 consumption or CO2 evolution) at various O2 and CO2 concentrations, as well as transient and equilibrium gas concentrations within permeable packages, could be accurately predicted with the model equations.