Abstract

Watermelon [Citrullus lanatus (Thunb) Matsum and Nakai] is rich in vitamins C and B complex, and the red color of its pulp is due to the presence of lycopene. Lycopene is an antioxidant component and it is able to neutralize free radicals especially responsible for skin aging. Thus, a formulation containing lycopene extracted from watermelon was developed, and its physical-chemical stability and in vitro antioxidant activity were evaluated. For this, watermelon endocarp was separated and heated for pulp obtainment. Lycopene was extracted from watermelon pulp with acetone and ether successively, spectrometric quantified, and finally had its in vitro antioxidant activity determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The resulting extract was then incorporated in an emulsion, which was submitted to physical-chemical stability study at different conditions. Results show the presence of 38 µg of lycopene/g of watermelon pulp and 68.78% of DPPH inhibition, presenting antioxidant activity by in vitro assay. The developed formulation was stable when submitted to stress conditions and results point that it should be conserved in opaque packaging. Thus, it was possible to conclude that lycopene extract from watermelon pulp can be considered as a source of antioxidant component to be used in cosmetic formulation combating skin aging.

Key words: Antioxidant, cosmetic, 1,1-diphenyl-2-picrylhydrazyl (DPPH), lycopene, watermelon.