Hydroxytyrosol 4-β-d-Glucoside, an Important Phenolic Compound in Olive Fruits and Derived Products

Abstract

There is increasing interest in olive polyphenols because of their biological properties as well as their contribution to the color, taste, and shelf life of olive products. However, some of these compounds remain unidentified. It has been shown that hydroxytyrosol 4-beta-D-glucoside (4-beta-D-glucosyl-3-hydroxyphenylethanol) coeluted with hydroxytyrosol [(3,4-dihydroxyphenyl)ethanol] under reversed phase conditions in the phenolic chromatograms of olive pulp, vegetation water, and pomace of olive oil processing. A method to separate this compound from hydroxytyrosol by HPLC has been developed. The concentration of this glucoside increased in olive pulp with maturation and could be the main phenolic compound in mature olives. In contrast, the presence of this compound was not detected in olive oil by using HPLC-MS. The compound must be considered both in table olives and olive oil processing because of its glucose and hydroxytyrosol contribution to these products.

Identification and characterisation of phenolic compounds extracted from Moroccan olive mill wastewater

“…Oleuropein, an ester of elenolic acid and hydroxytyrosol, identified as a major phenolic compound of OMWW (Dermeche et al, 2013;Visioli et al, 2002;Romero et al, 2002), was identified by its molecular ion at m/z 539 and by the presence of the hydroxytyrosol (m/z 153) ion fragment, only in the extracts derived from mountainous areas whereas we failed to identify this compound in the plain areas extracts. Oleuropein in these extracts had probably degraded into elenolic acid and hydroxytyrosol by an esterase during the mechanical olive oil extraction process .…”

The effect of replacing soya bean oil with glycerol in diets on performance, egg quality and egg fatty acid composition in laying hens

“…Haugh unit = 100 × log (AH + 7.57-1.7 × EW 0.37 ), where AH = albumen height and EW = egg weight. A colorimeter (Minolta Chromameter CR 400; Minolta Co., Osaka, Japan) to assess the egg yolk colour and the CIELAB colorimetric (Romero et al, 2002). Eggshell breaking strength was measured using a cantilever system by applying increased pressure to the broad pole of the shell using a Force Reader instrument (Orka Food Technology Ltd, Ramat Hasharon, Israel).…”

Kinetic study of the methanogenic step of a two-stage anaerobic digestion process treating olive mill solid residue

“…Phenolic compounds were extracted beforehand [14] and measured at 725 nm by spectrophotometry using the Folin-Ciocalteau method [9].…”