Modeling the Respiration Rate of Oranges Coated by Thymus Vulgaris Essential Oil to Develop Modified Atmosphere Packaging

In this work, the effectiveness of temperature, oxygen and Thymus vulgaris essential oil (Zataria multiflora) coated on the respiration rate of oranges (Citrus sinensis L.) cv. Valencia was studied to properly develop modified atmosphere packaging. Respiration rate of orange in the close system was studied at the range of temperature 5, 10 and 250C as well as the essential oil in the 3 level from 125, 250 to 500 ppm. A Michaelis–Menten-type equation, with the model constants used to describing the respiration rate of fruit. Our results show the efficacy of modelling for predicting of respiration rate in the varying oxygen concentration and storage time. Arrhenius-type relationship, was used for predicting respiration rate on varying the temperature. The results indicated that increasing in the storage temperature leading to decrease in the time of respiration rate and reach equilibrium state. The maximal respiration rate ( ) and value changes in the exponential and linear manner respectively with increase in the temperature. As well as, the essential oil coating led to decrease in the model parameters value estimated. The activation energy of the respiration rate based and for oranges was calculated at 53.12 and 21.18 respectively. In addition, the value of activation energy increased to the higher value in the presence of essential oil coating.