Industry-Friendly Hydroethanolic Extraction Protocols for Grateloupia turuturu UV-Shielding and Antioxidant Compounds

Abstract

Grateloupia turuturu is an invasive macroalga on the Iberian coast, known to produce bioactive compounds with different cosmeceutical bioactivities, namely UV shielding and antioxidants. The goal of this study was to optimize the extraction procedure of main bioactivities of this species with cosmetic potential, using Response Surface Methodology. Two Box–Behnken designs were used to evaluate the effect of ethanol concentration (0–50%), liquid-solid ratio, time, pH, and temperature on yield, UV absorbance, and antioxidant activity. Both optimizations showed a similar trend: aqueous extracts have higher yields and extracts performed with ethanol as part of the solvent have higher activities concerning UV absorbance and antioxidant activity. For all the extracts an absorption peak between 320 and 340 nm was observed. This data now allows further studies by narrowing the extracts worthful of characterization. The development of industry-friendly extraction methods allows the valorization of this invasive species, contributing for the potential creation of natural and eco-friendly products by the cosmetic industry while contributing to the restoration of affected environments.

Cosmeceutical Potential of Grateloupia turuturu: Using Low-Cost Extraction Methodologies to Obtain Added-Value Extracts

“…Optimal conditions for 4 hydroethanolic solid-liquid extracts of G. turuturu and 2 aqueous extracts were selected (see Table 1) according to the optimization of the extraction process performed by Félix and co-workers [9], and their extraction methodology was followed. Briefly, two optimization assays were performed using a response surface methodology with a Box-Benhken design.…”

“…Firstly, the solid-liquid ratio (SLR), the time of extraction (min) and the ethanol percentage were addressed. Then, using the results obtained for these 3 independent parameters, the influence of the extraction temperature ( • C), pH and ethanol percentage was evaluated [9]. For the production of the selected extracts of Grateloupia turuturu, 5 g of biomass with the selected volume of solvent was mixed under constant magnetic stirring and thermostatized during the selected time of extraction.…”

“…The antioxidant activity was measured by ORAC assay, according to Félix and colleagues [9] and Dávalos and co-workers [12]. Briefly, a Trolox stock solution (VWR, Radnor, PA, USA) was used to prepare the dilutions from 8 to 0.5 µM.…”

“…UV absorption was also performed according to [9]. Briefly, 200 µL of each extract (0.1 mg•mL −1 ) was added to a 96-well microplate for UV readings (Greiner UV-Star ® , Kremsmünster, Austria) as well as the respective blanks.…”

“…For that, solid-liquid extraction (SLE) is one of the most suitable solutions due to the ease to up-scale the production. In fact, for the specific case of G. turuturu, solid-liquid extraction using ethanol and water as solvents is an already optimized method to extract the main bioactive compounds [9].…”