Changes in ATP, ADP and pyridine nucleotide levels related to the incidence of physiological disorders in ‘Conference’ pears and ‘Jonagold’ apples during controlled atmosphere storage

SummaryThe effects of four controlled atmosphere (CA) storage conditions on ATP and ADP levels, and the concentrations of NAD(H) and NADP(H) were investigated in relation to the incidence of physiological disorders of ߢConference’ pears and ߢJonagold’ apples during six months at 08C(60.58C). ATP concentrations in apple and pear fruits stored in CA were lower than those in air-stored fruits but their reduction was lowest for ‘Conference’ pears stored in 1.5% CO2 1 1.5% O2. ‘Jonagold’ apples showed a sharp decrease followed by a slight increase in the ATP levels at the beginning of the second month of storage. The concentrations of NADH and NADPH in the tissues of ‘Conference’ pears and ‘Jonagold’ apples increased in both CA- and air-stored fruits. In contrast, the oxidized nucleotides, NAD and NADP, generally decreased with storage time and no signi®cant differences between the treatments were found. Only ‘Conference’ pears, when stored in 6% CO2 1 0.5% O2, exhibited a strong decline in NADP levels, which ...