Implementation of green extraction and isolation methodologies for the recovery of bioactive compounds from olive-growing products and by-products

Abstract

The experimental work of this PhD thesis has been scheduled on a three-axis base. Theaims that were set, they concerned the optimal exploitation of four different by-products of the table olive, olive oil and olive kernel oil industries, for the recovery of specific highadded-value compounds with well-known biological properties. Those natural productswere desired either in the form of enriched fractions or pure compounds. The prerequisitewas to utilize as eco-friendly technologies as possible for extraction and purification and tooptimize the processes in laboratory as well as in pilot scale. Thus, trustworthy estimationof industrial feasibility is provided. The main technologies that were implicated for therecovery of the target compounds are: Supercritical fluid extraction Pressurized liquid (and subcritical water) extraction Liquid/liquid extraction Adsorption resin technology Centrifugal Partition ChromatographyThe by-products that were the subject of the tracing/ extraction/ enrichment/identification/ quantification on studies for this PhD thesis were the following: Olive leaves (by-products of the pruning of the trees and of the olive fruit harvest) Olive mill pomace waste (biphasic process) Table olive process wastewater (by-product of the debittering process for theproduction of table olives) Olive kernel oil deodorization distillates (by-product of the refining process for theproduction of olive kernel oil from olive pomace)The natural compounds that were targeted for their recovery, enrichment and isolation dueto their well-established (and still under research) biological properties and theirapplication in pharmaceutical, phytotherapeutical, nutraceutical, cosmetic andcosmeceutical industries were respectively: Oleuropein Hydroxytyrosol SqualeneIn all cases, not only biomarkers’ content but also the overall chemical profile of theextracts was studied. The applied scientific interest of this work was that novel green extraction technologies and combinatorial processes as well as experimental design wereimplemented in lab and pilot scale for the exploitation of certain by-products that occur invery large quantities every year as a result of the agricultural/ industrial processing of theolive tree, with the aim of recovering high added value natural products.