Permeability of Different Wax Coatings and Their Effect on Citrus Fruit Quality

Gas and water vapor permeability (WVTR) of seven coatings, used commercially for citrus, was determined by coating these on highly permeable films. Oranges and mandarins were coated with the same seven coatings, and weight loss, appearance, internal gas composition, presence of ethanol and acetaldehyde, and flavor of these fruits were determined. There was a relationship between low concentrations of oxygen, which lead to off-flavors, and the presence of ethanol and acetaldehyde in the fruit. There was also a relationship between WVTR and weight loss of the fruit with most coatings, but no correlation between CO 2 and O 2 permeability of the coatings and concentration of these gases in the fruit. The above findings were validated in a semi-industrial trial.