Evaluating the effects of blanching and microwave pre-treatments on variations in some selected physiological factors of artichoke leaves in fluidized bed dryer

In this study, temperatures (40, 50, and 60°C), air velocity (3, 5, and 7 m/s) and pre-treatment (without pre-treatment, blanching, and microwave) were used as variables for investigation of antioxidant activity of dried artichoke leaves. The results revealed that variations in temperature and air velocity of the drying chamber and different pre-treatments significantly affected the free radical scavenging level and total phenol content in this plant. Based on the results obtained, it can be concluded that by increasing the temperature and air velocity and using blanching and microwave pre-treatments, the free radical scavenging level and total phenol content increased. The maximum percentage of free radical scavenging was 72.08% at 60°C and an air velocity of 7 m/s in the drying state by using microwave pre-treatment. The maximum total phenol content was 3.55 mg/g of dry matter at 60°C and an air velocity of 7 m/s in the drying state by using microwave pre-treatment.