Triterpene-Rich Supercritical CO2 Extracts from Apple By-product Protect Human Keratinocytes Against ROS

Abstract

Supercritical fluid extraction, employing CO2 as solvent, was explored to recover high-value lipophilic compounds from apple by-product, the main solid residue generated after apple fruit processing. The experimental conditions were fixed at pressures of 300, 425, and 550 MPa and temperatures of 37, 46, and 55 °C. The total yield from the extractions was calculated and the antioxidant capacity of the different extracts was measured by ORAC and HORAC analytical methods. Furthermore, HPLCDAD-MS/MS and GLC analyses were performed, respectively, for triterpenic compounds and fatty acid identification. The extracts were tested over human keratinocyte cell (HaCaT) to evaluate their in vitro impact. Supercritical fluid extracts obtained at 46 °C exhibited the greater operational yield and the highest concentration of triterpenic acids, namely, betulinic acid, oleanolic acid, ursolic acid, uvaol/erythrodiol, and lupeol. These results support that apple by-product is a natural source of bioactive compounds with potential cosmeceutical applications.