The influence of electron-beam ionization on ethylene metabolism and quality parameters in apricot (Prunus armeniaca L., cv Búlida)

The possibility of extending the post-harvest shelf-life of apricots (Prunus armeniaca, Búlida) by applying electron-beam ionization at doses of 0.5 and 1.0 kGy has been studied. Ionization treatment caused a decrease in the ethylene concentration in the climacteric peak; this effect was more pronounced at the greater dose (1.0 kGy). The free 1-aminocyclopropane-1-carboxylic acid (ACC) increased in control fruits and in those treated at 0.5 kGy, while it decreased at 1.0 kGy. The conjugated ACC showed an initial increase, sharper in control fruits, and a later decrease during the whole experiment. Both ACC synthase and ACC oxidase showed a lower maximum activity in ionized fruits than in control fruits. The texture of ionized fruits showed a higher loss of firmness than untreated fruits during storage, especially when they were ionized at doses of 1.0 kGy. However, the other physico-chemical parameters studied, color, total soluble solids content (TSSC), titrable acidity (TA), and carotenoids, showed no significant changes between control and ionized apricots. The ionization treatment at 0.5 or 1.0 kGy, despite its influence on the ethylene metabolism of fruit, was not effective for extending the shelf-life of apricot variety Búlida since, during storage, no significant differences between control and treated apricots were found in the physico-chemical parameters indicative of ripening.