Effects of irradiation on respiration and ethylene production of apple slices

Respiration and ethylene production rates of irradiated apple slices from four apple cultivars were measured for 72 h. Doses less than 1.2kGy had no effect on rates of CO₂ production and O₂ consumption, and irradiation at doses between 1.2 and 2.4kGy had minimal effect for all cultivars. Respiratory response of 'Idared', 'Law Rome' and 'Empire' slices to irradiation was curvilinear, with maximum respiration occurring in the 3-6kGy dose range. Response of 'Delicious' slices was linear over the irradiation dose range (0-11kGy) studied. Respiratory quotient increased with irradiation dose. The degree of maturity of the slices affected respiratory responses. Irradiation reduced ethylene production of all slices. These results suggest that irradiation doses of up to 2.4kGy can be used with minimum effect on the respiratory physiology of tissues. (C) 2000 Society of Chemical Industry.