APPLICATION OF AN ENZYME-KINETICS BASED RESPIRATION MODEL TO PERMEABLE SYSTEM EXPERIMENT OF FRESH PRODUCE

An unsteady state method and a steady state method of the permeable sy stem have been developed to measure the respiration rate of fresh prod uce and to estimate the parameters of enzyme kinetics based respiratio n model. In the unsteady state method, changes in O-2 and CO2 concentr ations over time inside a permeable package are curve-fitted to approp riate nonlinear equations, respiration rates are calculated by combini ng the derivatives of the nonlinear equations and the gas permeations through film, and then the parameters of the enzyme kinetics based res piration model are obtained from multiple linear regression of respira tion data versus gas composition. In the steady state method, respirat ion rates are calculated from steady state gas permeations of several packages, and curve-fitting of the data produces the respiration model parameters. The applicability of the two methods was verified success fully using several independent sets of experimental data. The advanta ge and disadvantage of the methods are discussed.