The influence of applied waxes on postharvest physiological behavior and pitting of grapefruit

The role of wax application on the development of a postharvest pitting of white grapefruit (Citrus paradisi 'Macf') was examined. Fitting developed on fruit coated with shellac-based waxes from three sources and, to a much lesser extent, on fruit coated with carnauba- or polyethylene-based wax. Non-waxed fruit did not pit. Fitting decreased with internal O-2 level and increased with internal CO2 level. Fitting increased with decreasing internal O-2 level and decreased with increasing CO2 level. Subjecting fruit to low O-2 (4%) alone induced pitting, but high CO2 (8%) had no effect. These results suggest that stimulation of postharvest pitting of grapefruit is caused in part by the reduction of internal O-2 levels. (C) 1998 Elsevier Science B.V. All rights reserved.