Effect of harvest maturity, storage condition and duration, on internal flesh browning and quality of 'Rosy Glow' apples grown in South Africa

'Rosy Glow' apple, being a sport variety of 'Cripps' Pink' apples, is regarded prone to internal flesh browning as its parent cultivar. This study investigated the effect of harvest maturity, storage temperature, 1-methylcyclopropene (1-MCP, SmartFresh^TM) treatment and storage duration in controlled atmosphere (CA) as factors influencing 'Rosy Glow' internal browning. Fruit were harvested at <40 and >50% starch breakdown (SB) for the harvest maturity trial (Trial 1) and <40% SB for the storage duration, temperature and 1-MCP trial (Trial 2). Trial 1 fruit was stored for 7 months in CA (1% CO₂ and 1.5% O₂) plus 6 weeks in regular atmosphere (RA) at -0.5°C and 7 d at 20°C and evaluated after each period. Trial 2 fruit treated with or without 1-MCP, was stored at -0.5 or 2°C and evaluated after 3, 5 and 7 months in CA plus 6 weeks in RA at -0.5°C and 7-day shelf-life (SL) period at 20°C. The fruit was evaluated for internal flesh browning types at the end of each storage period. Diffuse-, radial-, combination- and carbon dioxide (CO₂) browning were observed. Optimum harvested fruit proved to be less susceptible to diffuse- and radial browning. Fruit treated with 1-MCP had lower internal browning incidence. The fruit quality was better retained at -0.5 than at 2°C, which was different to previous 'Cripps' Pink' research findings. Diffuse and radial browning was first observed after 5 months in CA plus 6 weeks RA at -0.5°C. Diffuse browning was the most dominant browning type present. Post-harvest maturity (>50% SB) played a significant role in 'Rosy Glow' browning development. In this study fruit quality was better retained at -0.5 than at 2°C, while 1-MCP treated fruit maintained better quality than control fruit over time.