Influence of harvest date on ripening and volatile compounds in the scab-resistant apple cultivar ‘Golden Orange’

Abstract

SummaryThe quality of scab-resistant apple cv. ‘Golden Orange’, as influenced by harvest time, was evaluated in comparison with the scab-susceptible cv. ‘Golden Delicious’ (clone B) (Golden B). Fruits from both cultivars were harvested on three different dates and ripened at 20°C. Quality parameters at harvest [fruit mass, flesh firmness, starch hydrolysis, soluble solids content (SSC), titratable acidity (TA)], colour, ethylene production (EP), development of headspace volatiles during post-harvest ripening, and sugar and organic acid compositions at the end of ripening were measured. At harvest, firmness, SSC, TA, starch hydrolysis and Streif Index indicated that ‘Golden Orange’ apples were less mature than ‘Golden B’ apples, even if their skin colour was more yellow. Generally, during post-harvest ripening, ‘Golden Orange’ apples showed lower EP, lower total volatile production, and their skin turned as yellow as ‘Golden B’. ‘Golden Orange’ apples differed from ‘Golden B’ in their sugar, organic acid and volatile compound compositions. These differences were independent of harvest date and could explain the different sensory descriptions peculiar to this cultivar. Compounds that contributed most to the characteristic aroma were ethyl 2-methylbutanoate and hexyl and 2-methylbutyl acetate in ‘Golden B’ apples, and ethyl and hexyl 2-methylbutanoate, ethyl hexanoate and hexyl acetate in ‘Golden Orange’ fruit, at all harvest times. The concentrations of these volatiles were largely dependent on harvest date and on the length of post-harvest ripening.