THE INFLUENCE OF APPLIED WAXES ON POSTHARVEST PHYSIOLOGICAL BEHAVIOR AND PITTING OF GRAPEFRUIT

The role of wax application on the development of a postharvest pittin g of white grapefruit (Citrus paradisi 'Macf') was examined. Fitting d eveloped on fruit coated with shellac-based waxes from three sources a nd, to a much lesser extent, on fruit coated with carnauba- or polyeth ylene-based wax. Non-waxed fruit did not pit. Fitting decreased with i nternal O-2 level and increased with internal CO2 level. Fitting incre ased 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 o f postharvest pitting of grapefruit is caused in part by the reduction of internal O-2 levels. (C) 1998 Elsevier Science B.V. All rights res erved.