Published 2009-12-01
Abstract
Harvested ‘Flame’ grapefruits, navel oranges, and ‘Orlando’ tangelos were exposed to different washing treatments to determine their effects on color development during subsequent degreening. Control fruit were not washed before being degreened. Washing treatments included brush washing on a small research line, and washing on a commercial brush bed, high-pressure washer (HPW), or a combination of brush plus HPW wash. After washing, the fruit were exposed to 5 ppm ethylene at 70 or 85 °F with 95% relative humidity to stimulate color development characteristic of each type of citrus. Grapefruit color development was significantly inhibited compared to the control after washing on the research packingline for as little as 1 minute. Washed fruit could take more than twice as long to degreen as unwashed fruit. In tests conducted on a commercial packingline, fruit washed on both the brush bed plus HPW exhibited the greatest inhibition in color development compared to unwashed fruit. The HPW also significantly delayed fruit color development compared to the control, but the inhibition of degreening was the least of all the washing treatments. Treatments that most inhibited coloration also promoted the greatest water loss, suggesting that washing methods that disrupt the cuticle least, also inhibit degreening the least.