Determination of quality attributes of european plums (PRUNUS DOMESTICA L.) cultivars under different drying conditions

This study was carried out with Stanley's and Sugar's pulm fruit in two separate convective and microwave dryers such as cabin-type and precision. It determined the drying performance and final quality attributes of Stanley' and 'Sugar' plum fruit. The study also measured the quality characteristics such as color, acidity (pH), soluble solids content (SSC) (Brix), titratable acidity (TA), total phenolics (TP), and total antioxidants (according to TEAC and FRAP tests). Fresh samples of the fruits were dried in cabin-type dryers and at a drying air temperature of 60, 65 and 70°C; and in the microwave dryer, dried for 30-50s at 540W and 30-50s at 720W at power outputs-hold times. The products were dried to wet-based moisture levels of 10-15%. For ^Stanley plums, the closest color, pH, SSC, TA, TP, TEAC, and FRAP values to the values of the fresh fruits (in other words, the most appropriate drying conditions) were respectively achieved in cabin 60°C, cabin 60°C, precision 65°C, microwave 540 W-50 s, cabin 60°C, cabin 60°C and cabin 60-65°C – precision 70°C treatments. For ^Sugar plums, the closest values to fresh fruit were respectively obtained from precision 70°C, cabin 60°C, precision 70°C, microwave 540 W-50 s, cabin 60°C, cabin 60-65°C, and precision 65°C treatments. (author)