Applications of bioactive compounds extracted from olive industry wastes: a review

The wastes generated during the olive oil extraction process, even if presenting a negative impact for the environment, contain several bioactive compounds that have considerable health benefits. After suitable extraction and purification, these compounds can be used as food antioxidants or as active ingredients in nutraceutical and cosmetic products due to their interesting technological and pharmaceutical properties. The aim of this review, after presenting general applications of the different types of wastes generated from this industry, is to focus on the olive pomace produced by the two-phase system and to explore the challenging applications of the main individual compounds present in this waste. Hydroxytyrosol, tyrosol, oleuropein, oleuropein aglycone, and verbascoside are the most abundant bioactive compounds present in olive pomace. Besides their antioxidant activity, these compounds also demonstrated other biological properties such as antimicrobial, anticancer, or anti-inflammatory, thus being used in formulations to produce pharmaceutical and cosmetic products or in the fortification of food. Nevertheless, it is mandatory to involve both industries and researchers to create strategies to valorize these byproducts while maintaining environmental sustainability.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to C2TN (UIDB/04349/2020), CIMO (UIDB/00690/2020) and Joana Madureira (SFRH/BD/136506/2018). Lillian Barros thank the national funding by FCT, P.I., through the institutional scientific employment program-contract. The authors thank the European Regional Development Fund (ERDF), through the Incentive System to Research and Technological development within the Portugal2020 Competitiveness and Internationalization Operational Program for the mobilizing project “BIOMA” (POCI- 01-0247-FEDER-046112). The Agroenvironment Unit is supported by Junta de Castilla y León (Escalera de Excelencia CLU-2018-04) co-funded by the P.O. FEDER of Castilla y León 2014–2020.