Energy Consumption and Hypericin content in Drying leaves of St John’s Wort (Hypericum Perfoatum

Massive consumption of energy in the industry of drying makes it a matter of challenge regarding energy and economical aspects. Total energy consumption and the hypericin content in drying of St John’s Wort were determined using a hot-air dryer. Experiments were conducted at four air temperature levels (40, 50, 60, and 70°C), three air velocities (0.3, 0.7,and 1 m/s) and three sample thickness (1, 2 and 3 cm). Based on the results of data analysis, minimum and maximum levels of energy consumption were 0.56 and 3.24 kWh, respectively. Hypericin content decreased with increasing temperature and increased with increasing airvelocity and product sample thickness, so that the maximum and minimum hypericin amounts were 67 and 355 ppm, respectively

کلیدواژه ها:

Sample thickness ، Air temperature and velocity ، St John’s Wort ، hypericin