Autor(es): Sousa, Pedro ; Tavares-Valente, Diana ; Pereira, Carla F. ; Pinto-Ribeiro, Inês ; Azevedo-Silva, João ; Madureira, Raquel ; Ramos, Óscar L. ; Pintado, Manuela ; Fernandes, João ; Amorim, Manuela
Data: 2024
Identificador Persistente: http://hdl.handle.net/10400.14/44440
Origem: Veritati - Repositório Institucional da Universidade Católica Portuguesa
Assunto(s): Spent yeast; Glucans extraction; Skin safety
Glucans, a polysaccharide naturally present in the yeast cell wall that can be obtained from side streams generated during the fermentation process, have gained increasing attention for their potential as a skin ingredient. Therefore, this study focused on the extraction method to isolate and purify water-insoluble glucans from two different Saccharomyces cerevisiae strains: an engineered strain obtained from spent yeast in an industrial fermentation process and a wild strain produced through lab-scale fermentation. Two water-insoluble extracts with a high glucose content (> 90 %) were achieved and further subjected to a chemical modification using carboxymethylation to improve their water solubility. All the glucans' extracts, water-insoluble and carboxymethylated, were structurally and chemically characterized, showing almost no differences between both yeast-type strains. To ensure their safety for skin application, a broad safety assessment was undertaken, and no cytotoxic effect, immunomodulatory capacity (IL-6 and IL-8 regulation), genotoxicity, skin sensitization, and impact on the skin microbiota were observed. These findings highlight the potential of glucans derived from spent yeast as a sustainable and safe ingredient for cosmetic and skincare formulations, contributing to the sustainability and circular economy.
