Respiration and ethylene generation modeling of “Hass” avocado and feijoa fruits and application in modified atmosphere packaging

Abstract

A proper description of the respiration and ethylene generation is important in the development of package systems for the preservation of fresh fruits and vegetables. In this work, a model based on both Michaelis-Menten and chemical kinetics equations was developed and assessed in order to describe the respiration and ethylene generation of avocado (Persea americana cv. Hass) and feijoa fruits (Acca sellowiana Berg) from experimental data obtained at different temperatures by a closed system method. The temperature effect in both processes was described using Arrhenius-type relationships. After this, avocadoes and feijoas were packed in perforated low-density polyethylene (LDPE) and polypropylene (PP) bags for 8 days at 12°C and 80% RH to validate the usefulness of the model to describe the gas evolution in modified atmosphere packaging (MAP). For avocado fruits, respiration rates of 2680-3030 cm 3 kg-1 d-1 were obtained at 24°C and normal atmosphere, and 3650-4230 cm 3 kg-1 d-1 for feijoa fruits. As for ethylene production rates, at 24°C were obtained values of 3.11 cm 3 kg-1 d-1 for avocado and 0.50 cm 3 kg-1 d-1 for feijoa. At 6°C, respiration and ethylene production rates were up to 6 times lower. It was possible to describe properly the ethylene generation using a Michaelis-Menten simple equation and the respiration rates using a Michaelis-Menten uncompetitive kinetics for both fruits with coefficients of determination above 0.9 in each case. The overall model was validated in the MAP test being possible to predict successfully the O 2 , CO 2 and C 2 H 4 levels inside the packages.

A Multi–Level Approach for Simulation of Storage and Respiration of Produce

“…While these expressions are still not based on the detailed activity inside the fruit, they represent the temperature and the effect of CO 2 and O 2 concentrations and hence, they provide local variation that is suitable for CFD. In the present work, source term expressions are utilized from the work of Castellanos et al [6,38] for avocadoes and tomatoes, which are based on the UMM (Uncompetitive Michelis-Menten) enzyme kinetics. This model is based on maximum rates, dissociation and inhibition constants that are of the Arrhenius type providing complete dependence on species concentrations around the fruit and on temperature.…”

“…In order to implement respiration expressions into the CFD simulations, the volume-of-produce dependence that the models are based on need to be reformulated into an interfacial area dependence such that the source terms are converted into boundary fluxes that enter the CFD domain through the surface area of the produce. The technique depends on estimating the inside-fruit density and utilizing the fruit volume-to-surface area ratio as a means for transforming the expressions by Castellanos et al [6,38] for O 2 , CO 2 and C 2 H 4 that were utilized in modified atmosphere packaging 0-D models into the boundary flux expressions. Equations (1)-(3) provide the enzyme kinetic models by Castellanos et al [6,38] for O 2 , CO 2 and C 2 H 4 :…”

“…The technique depends on estimating the inside-fruit density and utilizing the fruit volume-to-surface area ratio as a means for transforming the expressions by Castellanos et al [6,38] for O 2 , CO 2 and C 2 H 4 that were utilized in modified atmosphere packaging 0-D models into the boundary flux expressions. Equations (1)-(3) provide the enzyme kinetic models by Castellanos et al [6,38] for O 2 , CO 2 and C 2 H 4 :…”

“…For simulated results of such a REV to be accurate, the shapes of the produce in the REV must be representative of the produce considered. While a spherical shape may be adopted to characterize produce like apples [3,4], the deviation from sphericity is significant in cases of strawberries [5], avocadoes [6] and for certain types of tomatoes and many other fruits and vegetables. Within the general area of porous media characterization and modelling, there has been significant effort directed over the past decades towards development of idealized shape models.…”

An Analysis of the Published Literature on the Effects of Edible Coatings Formed by Polysaccharides and Essential Oils on Postharvest Microbial Control and Overall Quality of Fruit

“…Other postharvest techniques, such as microwave, heating, ozonation, and controlled/modified atmosphere packaging, have been proposed as alternatives to replace the treatment of fruit with chemical fungicides. However, their negative impacts on fruit quality characteristics are considered drawbacks for a practical use (Aloui et al, 2014;Botondi, Moscetti, & Massantini, 2016;Castellanos, Mendoza, Gavara, & Herrera, 2017;Rodriguez & Zoffoli, 2016).…”