Determination of harvest date and effect of different storage systems on fruit quality of scarlet spur apple cultivar

In order to determine the optimum harvest time for Scarlet Spur apple cultivar grown in Isparta/Egirdir conditions, the fruit samples were picked up at 7 days intervals during 8 weeks starting from 5 weeks before the estimated harvest date. These samples were analyzed by the means of fruit weight, width-length development, starch content, fruit flesh firmness, soluble solid content (SSC), titratable acidity (TA), skin color and respiration rate. The fruit were harvested in two periods and stored under normal (NA) and controlled (CA) atmospheric conditions at 0°C temperature and 90±5% relative humidity. Half of the fruits kept under NA conditions were treated with 1-MCP at a dose of 625 ppb for 12 hours. For storage in CA conditions, 3 different atmosphere combinations were used: (1) 1% O2 + 3% CO2, (2) 3% O2 + 4% CO2 and (3) dynamic controlled atmosphere (DCA). For the DCA treatments; CO2 ratio was set to 1% and the minimum O2 level at which the stress signal was received was determined by the chlorophyll fluorescence sensor. Several chemical and physical analyzes were carried out at regular intervals on fruits that were stored in the cold and kept under 7-day shelf life conditions (20°C temperature and 60±5% relative humidity). It was determined that the optimum harvesting time of Scarlet Spur variety should have an average respiration rate of 5.5 mL CO2/kg s, an average hardness value of 75 N, and a starch level of 5-6 according to the scale generated. It has been observed that 1-MCP treated apple fruit can be stored successfully for 6 months in NA. The minimum oxygen level was found to be 0.2% in the DCA condition. Fruit were stored in low O2 atmosphere (0.5%) by adding a 0.3% safety margin. The best storage condition for apple fruit was DCA in terms of some quality criteria, and fruit could be successfully stored for 10 months in this condition.