Production in Large Quantities of Highly Purified Hydroxytyrosol from Liquid−Solid Waste of Two-Phase Olive Oil Processing or “Alperujo”

Abstract

The effect of hydrothermal treatment of two-phase olive waste (alperujo) on the solubilization of hydroxytyrosol was studied. Different conditions of saturated steam were assayed. A high amount of hydroxytyrosol was solubilized and increased with increasing steaming temperature and time, reaching 1.4-1.7 g/100 g of dry alperujo. The effect of acidic (H(2)SO(4)) and basic (NaOH) catalysts was also evaluated. Acid-catalyzed treatment was more effective at milder conditions, whereas the alkali-catalyzed conditions were not very suitable. In the present study, the extracted hydroxytyrosol was purified by means of a new, simple, and inexpensive chromatographic system, under international patent application (PCT/ES02/00058). From 1000 kg of alperujo, with 70% humidity, can be obtained approximately 4.5-5 kg of hydroxytyrosol. After a purification process, at least 3 kg of hydroxytyrosol, at 90-95% purity, would be obtained. The purified compound was identified by HPLC/UV and (1)H and (13)C NMR analyses, and its antioxidant activity was tested on refined olive oil without antioxidants by Rancimat method. The oxidative stability of refined olive oil was increased by a factor of 1.71 in the presence of 100 ppm of hydroxytyrosol.

Phenolic Molecules in Virgin Olive Oils: a Survey of Their Sensory Properties, Health Effects, Antioxidant Activity and Analytical Methods. An Overview of the Last Decade Alessandra

“…As commented above the researches that studied olive mill waste, brines olive drupes, tissues of olive cultivars, alperujo, olives, olive leaves were not included in Table 3 [49,161,[194][195][196][197][198][199]. Servili et al [200] in a HPLC investigation of the phenols present in olive fruit, VOO, vegetation waters and pomace, and subsequently by 1D-and 2D-NMR achieved the complete spectroscopic characterization of demethyloleuropein and verbasoside extracted from olive fruit.…”

Optimisation, characterisation and quantification of phenolic compounds in olive cake

“…The quantity and type of phenolic compounds in olive cake depends on the cultivar and maturity of the fruit, climatic conditions, storage time and processing technique (Allouche, Fki, & Sayadi, 2004;Fiorentino et al, 2003;Piperidou et al, 2000). The major phenolic compounds present in olive cake (Fernandez-Bolanos et al, 2002), oleuropein (Mulinacci et al, 2001), tyrosol (Allouche et al, 2004), caffeic acid (Lesage-Meessen et al, 2001), p-coumaric acid, vanillic acid (Bianco et al, 2003), verbascoside, elenolic acid (Mulinacci et al, 2001), catechol (Fiorentino et al, 2003) and rutin (Romero, Brenes, Garcia, & Garrido, 2002). In this study, the conditions for the extraction of phenolic compounds and antioxidant activities (i.e., time, temperature, sequential extraction and extraction solvents used) were evaluated and optimised.…”

Determination of 3,4-dihydroxyphenylglycol, hydroxytyrosol and tyrosol purified from olive oil by-products with HPLC in animal plasma and tissues

“…Alperujo was thermally treated at 200°C for 5 min in a ''steam explosion'' reactor used previously for HT extraction and quantification (Fernández-Bolaños et al, 2002). The liquid and solid phases were separated by centrifugation at 4700g in a semi-industrial machine with maxima operating capacity of 20 kg (RTL-4BD, Comteifa, S.L., Barcelona, Spain).…”

“…Finally the liquid rich in solubilised phenols was used for HT, DHPG and tyrosol purification. HT was purified by a novel patented system (Fernández-Bolaños et al, 2002). The system consists of two chromatographic columns in which HT with a purity of 50% and 96%, respectively, are produced.…”