The green generation of sunscreens: Using coffee industrial sub-products

Abstract

Spent coffee grounds and green coffee defective beans, which are industrial sub-products of coffee processing, have a potential use for cosmetic applications, due to their safety and high content in lipids that present interesting physicochemical properties. Sunscreen formulations in the form of water-in-oil emulsions might be a suitable application for these sub-products because providing a higher sun protection factor (SPF) for the same concentration of sunscreen activities than oil-in-water emulsions. The purpose of this work was to assess the biological effects of using the oil fraction of spent coffee grounds extracted with supercritical CO 2 and green coffee oil in the development of new generation of sunscreens with improved sun protection performance. The oil fractions were used to prepare w/o sunscreens involving a cold emulsification process, with purified water as disperse aqueous phase and TiO 2 and ZnO particles as stabilizers. The sunscreens were characterized in terms of mechanical, rheological and skin adhesion properties. In addition, the in vitro and in vivo biological properties of the formulations were evaluated, including safety and sunscreen water resistance tests. The use of two types of solid particles proved to be useful in the developed formulations, ensuring a high SPF with UVB/A protection, conferred by TiO 2 and ZnO, respectively. Moreover, the emulsion containing 35% w/w of the spent coffee grounds oil fraction presented promising characteristics in the improvement of water performance with a broad spectrum sun protection when compared to an emulsion containing 35% w/w of green coffee oil which improved the SPF in physical sunscreens. The formulations are industrial-scalable and suitable for topical use according to the rheological, mechanical and safety assessment. The use of spent coffee oil in cosmetic industry seems to be a suitable approach for the valorisation of waste from the coffee industry and presents promising characteristics in the improvement of sunscreen performance.

Design of novel starch-based Pickering emulsions as platforms for skin photoprotection

“…The increasing association of natural ingredients with antioxidant activity may also improve the photoprotective activity of sunscreen formulations. In fact, these natural ingredients present several advantages, such as the bioactivity, relative safety, and obtainment from renewable sources, low cost, besides the feasibility for application in a wide range of health care products, and are obtained from renewable sources [33]. Natural ingredients are a viable source of bioactive compounds, such as polysaccharides and polyphenols, namely, phenolic acids (chlorogenic acid, caffeic acid and p-coumaric acid, among others) and alkaloids, which can be applied in the pharmaceutical, food and cosmetic industries [34].…”

Development and Evaluation of Lipid Nanoparticles Containing Natural Botanical Oil for Sun Protection: Characterization and in vitro and in vivo Human Skin Permeation and Toxicity

“…Furthermore, compounds derived from natural sources like plants, that themselves have UV-absorbing properties and antioxidant activity [22,23], are seen as potential sunscreen ingredients to reduce the use of chemical filters. We followed this approach by developing SLNs loaded with vegetable oils from Brazilian flora, which is rich in antioxidant substances.…”

Valorisation of the Residues of Coffee Agro-industry: Perspectives and Limitations

“…However, in some cases caffeine was found in the fruiting body indicating that it was not completely degraded. Nonetheless, the results obtained so far suggest the feasibility of using coffee residues as a substrate without pre-treatment for the cultivation of edible and medicinal fungi [30]. Residues remaining after the fungal cultivation have been proposed to feed ruminants as several toxic compounds decrease while the protein concentration increases (~9%) [34,35].…”