Effect of cultivar type, maturation level, and sulfuration on sorption isotherms of apricots

Turkey is the leading country in fresh and dried apricot production and export worldwide. Moisture sorption isotherms illustrating sorption behavior of apricots can be used to estimate endpoint of drying time and safe storage moisture content for dried apricots. In this study, sorption isotherms for two apricot cultivars (Hacıhaliloğlu and Kabaaşı) at three maturation levels were developed by static gravimetric method over a range of 22.6%–84.32% RH at 25°C. Moisture sorption data were fitted to GAB, BET, Halsey, and Oswin models to estimate moisture contents of apricots. The type of cultivar, maturation level, and sulfuration had no significant effect on moisture sorption characteristics of apricots (p >.05). Best fitting GAB model exhibited a critical moisture content of 20% (wb) for dried apricots at a_w 0.65 for safe storage and drying process was suggested to be stopped when the apricots achieved moisture content of 18%–19% wb. Practical applications: This study revealed that two apricot cultivars showed similar sorption behaviors at constant temperature (25°C). Apricot maturation level and sulfuration process did not significantly affect adsorption and desorption behaviors. For appropriate handling of dried apricots, and reducing losses during storage, HHO and KA apricots should be dried to 18%–19% wb moisture content prior to packaging and kept below 20% wb moisture content for maintaining safe storage. The results of this study are expected be useful for improving dried apricot production and storage in practice.