Development and characterization of cosmetic applications for FucoPol

The constant development of new technologies and the interest in the incorporation of novel sustainable ingredients has rendered the cosmetic industry as one of the fastest growing industrial sec- tors. Consumers’ demand for the utilization of biodegradable ingredients has precipitated the utilization of natural polymers as stabilizers in newly developed emulsions. Due to its unique properties, FucoPol has great potential to be used in various topical applications, i.e., as stabilizer, sensorial improvement promoter, and drug delivery polymer. The main objectives of this study were the development and characterization of FucoPol-based emulsions for safe topical application, using production methods focused on cost-reduction, and further investigating the resulting system’s behaviour under in vitro conditions. FucoPol extraction was successfully optimized by ultrafiltration using a 30 kDa molecular weight cut-off (MWCO) membrane that allowed for a 37% reduction of the total water consumption and a 55% reduction of the extraction time. This improved downstream procedure resulted in a 10% increase in product recovery with higher purity, without impacting FucoPol’s sugar and acyl groups composition, molecular mass distribution or thermal degradation profile. As deacylation is known to alter the functional characteristics in various polysaccharides (e.g., xanthan gum), an alkaline treatment was developed and implemented to obtain a deacylated form of FucoPol (d-FucoPol). Deacetylation and desuccinylation were effectively achieved with 0.02 M NaOH, at 60 °C for 15 minutes, with no impact on the biopolymer’s sugar composition, pyruvyl group content and average molecular weight. Nonetheless, d-FucoPol displayed novel properties, differing from the native FucoPol mainly in its viscoelastic properties. d-FucoPol’s solutions’ apparent viscosity decreased by 68%, but they were not affected by the pH, maintaining the similar apparent viscosity in a wide range of pH values, a contrasting behaviour with native FucoPol. ...