Harvest Maturity and Storage Duration Influencing Flesh Browning in South African 'Cripps' Pink' Apples

摘要

Flesh browning in 'Cripps' Pink' apples (Malus x domestica Borkh.) can cause major economic losses to the South African fresh fruit export industry. The aim of the study was to determine which type of browning mostly occurs in the Ceres area of the Western Cape and whether harvest maturity, influences the disorder under South African conditions. Fruit were harvested at optimum (15-40 starch breakdown) and post-optimum maturity (>60 starch breakdown), and then stored for 1, 4 or 7 months in controlled atmosphere (CA) conditions (1 CO_2 and 1.5 O2) at -0.5 °C followed by 4 weeks in air, representing the maximum shipping time followed by 7 days under shelf-life at 20°C. Fruit maturity during storage as well as lipid peroxidation and ascorbic acidlevels were measured. Post-optimum harvested fruit had higher levels of diffuse flesh browning (DFB) and developed DFB sooner during CA storage compared with fruit harvested at optimum maturity. Lipid peroxidation was higher after 1 month in CA in post-optimum fruit but both optimum and post-optimum picked fruit had high levels of peroxidation after 4 months in CA. Total ascorbate concentrations in late-harvested fruit decreased between one and four months of CA storage, whilst it took four to seven months to decrease in fruit harvested at optimum maturity. The study indicated that harvest maturity and storage duration hence senescence are critical factors influencing the potential development of DFB in 'Cripps' Pink' apples under South African conditions.