Optimization of extraction conditions of polyphenols, antioxidant capacity and sun protection factor from Prunus spinosa fruits. Application in sunscreen formulation

The aim of this work was to obtain different extracts rich in polyphenols of the blackthorn by reflux and sonication and to test them in sunscreen formulation. In order to obtain the maximum content of polyphenols, a high antioxidant capacity and a high sun protection factor of these extracts, a central composite design was employed to optimize the extraction parameters. The extraction time (30–150 min) and the ethanol concentration (40–80%) were considered for refluxing, and the extraction time (5–30 min), temperature (30–70 °C) and the ethanol concentration (40–80%) were for ultrasound-assisted extraction. The optimal conditions were found to be 30% ethanol concentration and the time 45 min for reflux extraction and the temperature 67 °C, the ethanol concentration 40% and time 10 min for ultrasound-assisted extraction. Due to antioxidant and photo protective properties of the blackthorn extract and its usage in sunscreen formulation, in vitro sun protection factor and photostability of the sunscreen formulation were also determined. Results from this study showed that the blackthorn fruit extract has importance utility in formulation with solar protection properties.