Influence of impact and compression mechanical damage on respiration of Fuji Suprema and Royal Gala apples

Abstract

The intensity of cell respiration is related to the storage potential of a horticultural product. In the case of apples the main modification during storage is the metabolization of organic acids. Mechanical damage is frequent in fruit post harvest handling and the external forces involved can accelerate the respiratory pattern of fruits leading to further losses. The objectives of this work were to evaluate the effects of mechanical damage by impact and compressing on the respiratory pattern of Fuji Suprema and Royal Gala apples. The experiments consisted of five treatments with three repetitions of six fruit each. After the treatment application, fruit were set in closed flasks and maintained in room temperature during the CO₂ determination (ml CO₂ kg^-1 h^-1). The measurements were made with a CO₂ analyzer equipped with a zircon detector. The readings were taken at 0, 1, 2, 4, 6, 24, 48 e 168 hours after the treatment and data were submitted to a regression analysis. There was an increase in fruit respiration after the treatment application. The respiratory profiles along the evaluated period show increase of the respiratory rate after the treatment application. The greatest increase for most treatments occurred within the first six hours after the treatment, with posterior reduction. The regression curves of the respiratory rate in function of the treatment applied showed there is an increment in the respiratory rates associated with the intensity of applied forces. The increments of respiratory rates were greater for Gala than Fuji apples and impacts produce a greater effect over the respiration than compression forces.