Nikos Xynos

Development of a Sustainable Procedure for the Recovery of Hydroxytyrosol from Table Olive Processing Wastewater Using Adsorption Resin Technology and Centrifugal Partition Chromatography

The present endeavor aims to establish a novel procedure, applicable to the extraction and isolation of hydroxytyrosol from table olive processing wastewater. A two-step chromatographic separation is presented using non-ionic absorbent resin for the recovery of its phenolic content, followed by purification of hydroxytyrosol with centrifugal partition chromatography. Two table olive processing wastewaters, obtained from Kalamon and Amfissis olive varieties, were used. In the extracts obtained after resin treatment, the hydroxytyrosol content was determined by high-performance liquid chromatography with diode-array detection to be 4.05% and 10.10%, respectively. The extract from Amfissis table olive processing wastewater was further processed with preparative centrifugal partition chromatography for the purification of hydroxytyrosol. High-performance liquid chromatography analysis revealed that the isolated compound was >95% purity.

A single-step isolation of squalene from olive oil deodorizer distillates by using centrifugal partition chromatography

ABSTRACT High added-value squalene (SQ) was purified in one step from olive oil deodorizer distillates (OODD) using preparative centrifugal partition chromatography (CPC) method, operating in the dual mode. The fractionation was performed using a non-aqueous biphasic solvent system consisting of heptane–acetonitrile–butanol (1.8:1.4:0.7, v/v/v), leading to the isolation of the target compound in 4 hours, using a preparative 1L column. Furthermore, a fast UHPLC-DAD method was developed and applied for the identification and quantification of SQ in both OODD and purified form. The content of SQ in the initial material was 23.4%, while the purity of the isolated SQ was 95.5%. The recovery of SQ was calculated at 76.3%. The productivity of the process was calculated at 234 mg/h/L.

Recovery of High Added Value Compounds from Olive Tree Products and Olive Processing Byproducts

Publisher Summary Olive oil and table olives are rich in bioactive natural compounds. Both the cultivation of olive trees and the process of industrial olive oil and table olive production generate enormous quantities of solid wastes and dark liquid effluents, most of them with no practical applications. These wastes contain considerable amounts of valuable substances such as carbohydrates, organic acids, mineral nutrients, oils, fibers, and phenols that are variably distributed among the different wastes, depending on the process followed for the production of oil and table olives and the agronomic practices. These wastes are either exploitable at low technological and economical levels or, in the worst case, are disposed in nature, creating major environmental problems. Among the compounds reported in these materials, the phenolic compounds constitute an interesting group endowed with a wide array of biological activities. The main byproducts of the olive processing industry that this chapter describes are: (1) olive leaves, (2) olive pomace, (3) Olive Oil Mill Waste Water (OMWW), and (4) Table Olive Processing Wastewater (TOPW). The chapter focuses on their content in valuable components, the applied valorization methods and techniques for their recovery, and their possible applications in the market.

Novel Natural Products for Healthy Ageing from the Mediterranean Diet and Food Plants of Other Global Sources—The MediHealth Project

There is a rapid increase in the percentage of elderly people in Europe. Consequently, the prevalence of age-related diseases will also significantly increase. Therefore, the main goal of MediHealth, an international research project, is to introduce a novel approach for the discovery of active agents of food plants from the Mediterranean diet and other global sources that promote healthy ageing. To achieve this goal, a series of plants from the Mediterranean diet and food plants from other origins are carefully selected and subjected to in silico, cell-based, in vivo (fly and mouse models), and metabolism analyses. Advanced analytical techniques complement the bio-evaluation process for the efficient isolation and identification of the bioactive plant constituents. Furthermore, pharmacological profiling of bioactive natural products, as well as the identification and synthesis of their metabolites, is carried out. Finally, optimization studies are performed in order to proceed to the development of innovative nutraceuticals, dietary supplements or herbal medicinal products. The project is based on an exchange of researchers between nine universities and four companies from European and non-European countries, exploiting the existing complementary multidisciplinary expertise. Herein, the unique and novel approach of this interdisciplinary project is presented.

Antioxidant effects of an olive oil total polyphenolic fraction from a Greek Olea europaea variety in different cell cultures

BACKGROUND Numerous studies have been carried out concerning the advantageous health effects, especially the antioxidant effects, of olive oils (OO) individual biophenolic compounds, but none until now for its total phenolic fraction (TPF). Plenty of evidence, in research about nutrition and healthiness, points out that it is the complex mixture of nutritional polyphenols, more than each compound separate, which can synergistically act towards a health result. PURPOSE The aim of the present study was to examine the antioxidant properties of an extra virgin olive oil (EVOO) total polyphenolic fraction, from a Greek endemic variety of Olea europaea in cell lines. METHODS EVOO from a Greek endemic variety was used for the extraction of a total polyphenolic fraction, using a green CPE‑based method. The redox status [in terms of ROS, GSH, TBARS, protein carbonyls] was assessed at a cellular level, particularly in EA.hy926 endothelial, HeLa, HepG2 hepatic cells and C2C12 myoblasts. Moreover, the levels of glutamate-cysteine ligase catalytic subunit (γ-GCLc) of GSH, one of the most important antioxidant enzymes, were assessed by western blot. RESULTS According to the results, TPF improves the redox profile of all cell lines, mainly by increasing GSH and its catalytic subunit, while at low, not cytotoxic TPF concentrations there was a decrease in TBARS and carbonyls. Regarding ROS levels a reduction was observed only in the HepG2 cell line, contrary to the other cell lines, that there is no statistically significant difference. CONCLUSION The TPF appeared to protect cells from oxidative stress due to the strong antioxidant activity of its polyphenols. This could have interesting implications in development of new products based on this olive oil to provide protection and treatment against harmful effects of free radicals.