Designing equilibrium modified atmosphere packages for fresh-cut vegetables subjected to changes in temperature

Storage temperature is never constant in the distribution chain of fresh foods. Due to the temperature dependence of respiration of fresh produce and O(2) permeability of a packaging film, fluctuating temperatures result in changes of the internal O(2) and CO(2) concentration of Equilibrium Modified Atmosphere (EMA) packaged fresh produce. Therefore, the design of EMA packages was improved by adding mathematical models describing the effect of temperature, O(2) and CO(2) levels on produce respiration. The influence of temperature on respiration was described by an Arrhenius type of equation while the influence of O(2) and CO(2) on respiration was modelled by a Michaelis-Menten kinetic for 10 types of fresh-cut produce. Compared to unprocessed vegetables a higher temperature dependence of cut/shredded produce was observed. An integrated mathematical model characterized the effect of produce type, produce weight, temperature, O(2) and CO(2) dependence of produce respiration,film type, package area and temperature dependence of film permeability for O(2) in order to predict the internal O(2) concentration of an EMA package which was designed for equilibrium concentration of 3 mL/100 mt O(2) at 7 degrees C. The model was validated by packaging 10 types of fresh-cut vegetables and comparing equilibrium O(2) levels with those predicted at six different temperatures between 2 and 15 degrees C.

http://ift.tt/2rtWS6f