Overcoming challenges in the development of cosmetic formulations with agro‐industrial by‐products: The case of cork powder

Key challenges in transforming cork by-products into cosmetic ingredients include the standardization of the preparation process, batch uniformity and suitable microbiological burden. Sieving, washing, filtration and heat treatment of cork powder reduced microbial burden and improved batch uniformity. Industrial processing did not introduce contaminants, with heavy metal levels remaining below regulatory limits for cosmetic use. The treatment and storage conditions adopted preserved the physicochemical properties, and pre-formulation and stability studies validated its potential as a sustainable innovative ingredient for decorative and mattifying cosmetics. Transforming by-products into cosmetic ingredients is a stepwise process that must be carefully carried out to ensure optimal performance.