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 cm³ kg^-1 d^-1 were obtained at 24 °C and normal atmosphere, and 3650-4230 cm³ kg^-1 d^-1 for feijoa fruits. As for ethylene production rates, at 24 °C were obtained values of 3.11 cm³ kg^-1 d^-1 for avocado and 0.50 cm³ 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 O₂, CO₂ and C₂H₄ levels inside the packages.

KEYWORDS:

• Michaelis-Menten
• Arrhenius
• Uncompetitive inhibition
• Chemical kinetics
• Fruit storage

Funding

The authors are grateful for the financial support provided by the Colombian Administrative Department of Science, Technology and Innovation—COLCIENCIAS with its Doctoral Scholarships Program (Convocation 567).

Additional information

Funding

The authors are grateful for the financial support provided by the Colombian Administrative Department of Science, Technology and Innovation—COLCIENCIAS with its Doctoral Scholarships Program (Convocation 567).