Exploiting the Nutraceutical Potential of Polyphenol-Rich Extra Virgin Olive Oils Through Optimized Sustainable Phenolic Recovery

Abstract

Recently developed polyphenol-rich extra virgin olive oils (EVOOs) are well-known for their health-promoting properties and provide the opportunity to extract polyphenolic content for innovative nutraceutical development. The extraction of phenolics from three polyphenol-rich EVOOs was optimized using response surface methodology (RSM) and ethanol/water mixtures. The effects of water content in ethanol and the solvent-to-oil ratio were evaluated based on results obtained using the Folin–Ciocalteu method. The extracts produced under the optimum conditions were also subjected to HPLC-DAD analysis and their phenolic profiles were obtained. The models derived showed high statistical significance (p ≤ 0.001) and a good fit to the experimental TPC data, as reflected by their R2 values of 94.41%, 96.25%, and 93.85%, for EVOOs -A, -B, and -C, respectively. Optimum extraction conditions (100% ethanol, ratio of 7.4–10:1) maximized phenolic yield of 1365.80, 1045.56, and 1005.67 mg Tyr. Eq./kg, for EVOOs -A, -B, and -C, respectively. The optimized extracts were validated in terms of their phenolic profiles, revealing high amounts of hydroxytyrosol, tyrosol, oleocanthal, oleuropein, ligstroside aglycone, and oleacein. These findings contribute to the efficient recovery of polyphenols from polyphenol-rich EVOOs for potential use in the development of innovative nutraceutical supplements, medicinal formulations, and/or functional foods.