Drying parameters influence in organic apples quality

Abstract

The organic dried fruits market is in a growing demand in Romania, especially due to the important amounts of nutrients for human health that the fruits bring. In this study we aimed to test the influence of different pre-treatment and drying temperatures on physical and biochemical characteristics in two organic apple varieties (‘Topaz’ and ‘Dalinette’). Both varieties were washed, cored, sliced and hot-water blanched in order to inactivate the enzymes that produces the browning reaction. As control, untreated apple slices were dried in the same conditions as those pre-treated. Two temperature were used in order to assess the drying conditions, 40 °C and 70 °C. Results shown that different drying periods are required for organic apple ‘Topaz’ and ‘Dalinette’. When control samples were dried, 18 hours where necessary for ‘Dalinette’ variety to reach 95 ± 3 % dry matter, compared to 14 h for ‘Topaz’ variety. The drying period was dependent of both applied pre-treatments and temperatures. After drying, it was observed an increase in phenolic content and antioxidant activity for both pre-treated organic apple varieties. Both pre-treatment and higher temperatures (70 °C) affected the ascorbic acid content for ‘Dalinette’ apple slices.

Keywords

• apples
• drying
• hot-water blanching
• fruit chips
• titratable acidity
• dry matter content
• antioxi-dant activity