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Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/19/2000 Publication Date: 5/16/2000 Citation: N/A Interpretive Summary: Oranges and grapefruit sold as fresh fruit often have off-flavor, the degree of which is much influenced by the type of coating that is applied in the packinghouse. As is generally known, in order to make citrus fruit have high gloss, the ordinary resin-based citrus coatings used in U.S. packinghouses tend to block gas transfer through the peeling so that the fruit cannot 'breathe', and the result is off flavor. In order to have high gloss and at the same time avoid coatings that cause off-flavor, more information is needed on the how different coatings affect flavor. In the present study we determined the shelf life according to the rate of flavor deterioration. Marsh grapefruit and Valencia oranges, respectively, had shelf lives of 2 weeks and 6 days at room temperature when the resin-based coatings were used. However, with coatings made from waxes the flavor deterioration was much slower, and oranges had shelf life of over two weeks. Flavor deterioration with all coatings was lessened by reduction in storage temperature to 15C. Technical Abstract: 'Marsh' grapefruit and 'Valencia' oranges were coated with shellac or wax-based coatings. The shelf life of 'Valencia' oranges with a typical shellac-rosin coating was approximately 7 or 5 days when stored at 21 or 25C, respectively, based on flavor decrease and ethanol increase. The shelf life was >16 days at 15C storage with the same coating or at 15-25C with a polyethylene-candelilla wax coating. The ethanol content of 'Marsh' grapefruit increased at a slower rate than that of 'Valencia' oranges during storage, and the flavor at a slower rate. Grapefruit and oranges coated with the shellac-rosin coating did temporarily have better gloss, but this advantage was lost during storage. Postharvest pitting of grapefruit was higher with the shellac-rosin coating than with wax coatings. |
