STORABILITY AND FRUIT QUALITY OF ORGANICALLY GROWN 'TOPAZ' APPLES AS AFFECTED BY HARVEST DATE AND DIFFERENT STORAGE CONDITIONS

Abstract

Fruits from 6-year-old 'Topaz' (Malus × domestica 'Topaz') trees were harvested at two different stages of maturity (Optimal harvest date OHD, OHD + 1 week) from the same transitional organic orchard in the experimental station of Haidegg in 2007. After harvest fruits of each stage of maturity (ca. 80 kg) were stored for approximately 8 months under different storage conditions (controlled atmosphere and dynamic controlled atmosphere). Recommended CA conditions were used as a reference (1.5°C, O 2 1.5%, CO 2 3.0%) and DCA was based on the fruit's fluorescence response to low oxygen stress, O 2 was set at 0.3-0.4% plus 1.5% CO 2 in DCA. After 240 days storage and a 7 days shelf-life period at 20°C fruit quality was assessed automatically with the Pimprenelle laboratory device. Browning disorders (cavities, flesh and brown core) and storage diseases were estimated visually. DCA storage maintained firmness and titratable acidity at higher levels compared to CA. DCA storage technology reduced browning disorders for more than 67% and Gloeosporium rot (GR) to 18% related to fruits stored only in CA. Neither low O 2 and nor external CO 2 injury was observed in DCA.