Utilization of olive mill waste waters to produce bioactive animal feed

Abstract

Olive biomass as a source of bioactive compounds is a priority in the applied research. Regarding the extraction of valuable compounds that may be marketable in the pharmaceutical and cosmetic industries, Galanakis and Kotsiou described different technologies for the recovery of bioactive compounds from olive oil processing byproducts and suggested an integrated method that ensures the sustainability of the process. The most widely-used technique is to pretreat the initial material and convert oleuropein to hydroxytyrosol, prior to extracting phenols with solvent and/or other technologies. Fernández-Bolaños et al. summarized the current knowledge on the utilization of residual products, with more than 90 references including articles and patents, and highlighted promising future applications. They classified all these studies into two options for use: the recovery of valuable natural components, and bioconversion into useful products. Olive mill waste water (OMWW) is a rich source of bioactive compounds and natural phenols, including hydroxytyrosol a natural phenolic phytochemical with remarkable antioxidant properties that potentially affect blood lipid levels. Phenols such as hydroxytyrosol, tyrosol, oleuropein recovered from OMWW are also active UV filters used in cosmetics. An interesting possibility is the application of the “cascading use” principle, whereby energy use is allowed only after valuable compounds have been extracted. © 2022 Elsevier Inc. All rights reserved.