University of Tehran Press Iranian Journal of Biosystem Engineering 2008-4803 47 2 2016 08 22 Effects of hot air drying method on hypericin extracted content of Hypericum perforatum L. leaves. Effects of hot air drying method on hypericin extracted content of Hypericum perforatum L. leaves. 301 306 58779 10.22059/ijbse.2016.58779 FA Hosein Ahmadi Chnarben Seyede Masoumeh Hashemi Nia Journal Article 2015 08 11 Drying is considered as one of the important stages after plant harvesting which plays an important role in maintaining the quantity and quality of their active ingredients. St. John's wort (Hypericum perforatum L.) is an important medicinal plant that high percentages of hypericin in its leaves and flowers are considered as the most important feature of the Iranian species. In this research, effect of three treatments including the temperature at three levels of 40, 50 and 60°C, the air velocity at two levels of 0.3 and 1 m/s and the bed depth at two levels of 1 and 2cm were investigated in terms of the effect on extraction of hypericin. Considering the results the highest amount of hypericin was obtained during the drying process at 40°C and in a hot air velocity of 1 m/s and in the bed depth of 1cm and with the amount of 865.41 μg/g dry weight and the lowest was obtained during the drying process at 60°C and the hot air velocity of 0.3 m/s and in the bed depth of 2 cm and with the amount of 587.31 μg/g dry weight. Drying is considered as one of the important stages after plant harvesting which plays an important role in maintaining the quantity and quality of their active ingredients. St. John's wort (Hypericum perforatum L.) is an important medicinal plant that high percentages of hypericin in its leaves and flowers are considered as the most important feature of the Iranian species. In this research, effect of three treatments including the temperature at three levels of 40, 50 and 60°C, the air velocity at two levels of 0.3 and 1 m/s and the bed depth at two levels of 1 and 2cm were investigated in terms of the effect on extraction of hypericin. Considering the results the highest amount of hypericin was obtained during the drying process at 40°C and in a hot air velocity of 1 m/s and in the bed depth of 1cm and with the amount of 865.41 μg/g dry weight and the lowest was obtained during the drying process at 60°C and the hot air velocity of 0.3 m/s and in the bed depth of 2 cm and with the amount of 587.31 μg/g dry weight. https://ijbse.ut.ac.ir/article_58779_503decfee86d13987805d37b881ac6bd.pdf