Bioactive extracts from edible nettle leaves using microwave hydrodiffusion and gravity and distillation extraction techniques

Abstract

Microwave hydrodiffusion and gravity (MHG) was compared with conventional steam distillation from edible nettle leaves. The optimum MHG-extract was collected at 100 W, with the lowest energy consumption (∼788 kJ) and the highest total phenolic content or antioxidant capacities (∼0.04 mg GAE/g nettle leaves dry weight or 0.11 mg Trolox eq/g nettle leaves dry weight). Similar chemical, bioactive and stability features were obtained for creams with added nettle leave extracts and commercial antioxidants. Rheology of emulsions with different type of water did not present differences apart from samples made with thermal water 3 and MHG-extract. The addition of MHG-extract in the shampoo provided an increase of their foaming ability and stability jointly with an initial positive change of the lightness on the volunteer’s natural hair (ΔL*∼2.6).