Effect of Drying Methods on Phenolic Compounds and Antioxidant Activity of Urtica dioica L. Leaves

Stinging nettle (Urtica dioica) is a plant well known in traditional medicine for its many beneficial properties, but the lack of standardization regarding product to offer consumers limits diffusion. To this end, drying appears be useful technique low-cost that can stored long time, different procedures may give rise end-products very quality as nutraceutical and antioxidant compounds. Nettle leaves have been dehydrated employing freeze-drying (FD), oven-drying (OD) or heat pump (HPD) compared with fresh following water extraction emulate use by final consumers. Results indicate best dehydration HPD, which apparently gives more than doubling total phenols activity extract obtained from reduction level ascorbic acid about 39%. In addition, content some phenolic compounds 10 over hundred times higher after HPD samples. This confirms should tuned relation greatest interest value.