Hydroxytyrosol Recovery From Olive Mill Wastewater: Process Optimization and Development of a Pilot Plant

Abstract

The olive oil industry is a sector of high relevance in the economy of the European Union; indeed, three quarters of the world production is concentrated in the South Europe. Unfortunately, the commonly used milling techniques generate huge amounts of highly polluting olive mill wastewater (OMWW) as a side‐product. If released in the environment, untreated OMWW have a detrimental impact on land and water because of the large amount of phytotoxic phenolic compounds contained. At the same time, due to their powerful antiradical properties, polyphenols represent the center of a very valuable market niche, where they find application in cosmetic and nutraceutic fields. Consequently, the mandatory (for evident environmental reasons) depollution of OMWW associated with an efficient and selective recovery of the phenolic fraction could be economically very advantageous. In the present study, a new methodology employing activated charcoal as the adsorbent phase was developed in order to depollute OMWW and simultaneously recover a fraction enriched in hydroxytyrosol, the most abundant and valuable phenolic compound present in this matrix. Moreover, to evaluate the technical and economic feasibility of the process at a pre‐industrial level, this strategy was submitted to a scale‐up process and a pilot plant prototype was developed.

Polyphenolic Fraction from Olive Mill Wastewater: Scale-Up and in Vitro Studies for Ophthalmic Nutraceutical Applications

“…Cerasuola-OMWW characterization was performed as described in previous works [26,28] and results are summarized in Table 2.…”

“…Cerasuola-OMWW samples were centrifuged at 4000 rpm (2688 g) for 20 min to remove any solid residues of drupes and leaves and the supernatant was filtered through filter paper under vacuum condition as reported by Fava et al (2017) [26]. Filtered OMWW were subjected to a flash-freezing process to avoid degradation of polyphenolic compounds and to ensure long-term stability and reproducibility of analyses.…”

Optimizing the Extraction Conditions of Hydroxytyrosol from Olive Leaves Using a Modified Spherical Activated Carbon: A New Experimental Design

“…The efficient extraction of polyphenols from waste materials leads to their value-added utilization, with advantages in diverse aspects including environmental, sustainability, and health [ 2 , 3 ].…”

Polyphenol-Rich Extracts from Agroindustrial Waste and Byproducts: Results and Perspectives According to the Green Chemistry and Circular Economy

“…Similarly, Fava et al (2017) designed an automated process for polyphenol extraction from the OMWW to obtain about 2 kg of polyphenolic extracts by treatment of 300 L of the OMWW, and the procedure proved to be reproducible for up to three cycles. Residues, consisting mainly in Tyr and HTyr, were characterized with HPLC and showed an average purity of the latter of 70% . HTyr fractions with different purities were obtained from byproducts generated during olive oil manufacturing process: columns filled first with a strong anion exchanger (Amberjet 4200-Cl, Rohm-Haas Co., Chauny, France) and then with a polymeric absorption resin XAD type allowed for the isolation to HTyr up to 96% pure .…”