Search results for "Tyrosol"
showing 10 items of 43 documents
Extra-virgin olive oils storage: Effect on constituents of biological significance
2021
Abstract The high oxidative stability of virgin olive oil with respect to other vegetable oils is mainly due to its fatty acid composition, in particular, to the high monounsaturated-to-polyunsaturated ratio, and to the presence of minor compounds that play a major role in preventing oxidation. In spite of its high stability, virgin olive oil is susceptible to oxidative processes, such as enzymatic oxidation, photooxidation, and autoxidation, which mainly occur during processing and storage. Generally, extra-virgin olive oil has a relatively long shelf life of 16–18 months of storage at room temperature. The study of shelf life is generally based on determining of quality parameters (acidit…
Improved bioaccessibility and antioxidant capacity of olive leaf ( Olea europaea L.) polyphenols through biosorption on Saccharomyces cerevisiae
2016
Abstract Olive ( Olea europaea L.) leaves (OL) are natural by-products that can be used as an advantageous rich source of bioactive compounds, especially polyphenols. This study investigated the potential use of Saccharomyces cerevisiae as a new carrier of OL antioxidants and a means to protect their bioactivity during simulated gastrointestinal digestion. The biosorption on S. cerevisiae allowed the recovery of 25.17 mg/g and 49.40% of the polyphenols from olive leaf (var. Chemlali ) infusions. Both infusions and suspensions before and after biosorption were analyzed for total soluble polyphenols and total antioxidant capacity (oxygen radical absorbance capacity (ORAC) and trolox equivalen…
Effect of daily intake of pomegranate juice on fecal microbiota and feces metabolites from healthy volunteers
2015
cope The purpose of the study was to evaluate the effect, regarding the metabolic and microbial profile of feces, of diet supplementation of healthy adults with pomegranate juice (PJ). Methods and results Twelve healthy adults were recruited to the study, which consisted of the intake of 200 mL/day of PJ during 4 weeks. Feces were collected before and after the supplementation with PJ. Metabolites (phenolic catabolites, short-chain fatty acids, and fecal steroids) and microbial profile were analyzed at baseline and at 4 weeks. Fecal phenolic metabolites, 3-phenylpropionic acid, catechol, hydroxytyrosol, and urolithin A, showed a significant increase in their concentration after supplementat…
Nutraceutical properties of extra-virgin olive oil: a natural remedy for age-related disease?
2013
The health benefits of the Mediterranean diet can be largely ascribed to the nutraceutical properties of extra-virgin olive oil (EVOO). Mono-unsaturated fatty acids and various phenolic compounds, such as oleocanthal, oleuropein, hydroxytyrosol, and tyrosol, are the main nutraceutical substances of EVOO. These substances have been suggested to have the ability to modulate aging-associated processes. In experimental models, it has been shown that EVOO with high concentrations of polyphenols has anti-inflammatory and anti-oxidant properties. Indeed, it was observed that hydroxytyrosol and oleocanthal inhibit the cyclooxygenases (COX-1 and -2) responsible for prostaglandin production; oleurope…
Protection by extra virgin olive oil against oxidative stress in vitro and in vivo. Chemical and biological studies on the health benefits due to a m…
2017
Abstract We report the results of in vivo studies in Caenorhabditis elegans nematodes in which addition of extra virgin olive oil (EVOO) to their diet significantly increased their life span with respect to the control group. Furthermore, when nematodes were exposed to the pesticide paraquat, they started to die after two days, but after the addition of EVOO to their diet, both survival percentage and lifespans of paraquat-exposed nematodes increased. Since paraquat is associated with superoxide radical production, a test for scavenging this radical was performed using cyclovoltammetry and the EVOO efficiently scavenged the superoxide. Thus, a linear correlation (y = -0.0838x +19.73, regres…
Gluten-free flours from cereals, pseudocereals and legumes: Phenolic fingerprints and in vitro antioxidant properties.
2018
The interest in gluten-free (GF) products increases together with the increase in gluten-sensitive people. However, GF foods might have decreased nutritional quality as compared to the gluten containing counterparts. In this work, an investigation of the phenolic and antioxidant profile in 18 GF flours belonging to legumes, cereals and pseudocereals was achieved. Significant differences could be observed across samples. Total phenolic content was highest in violet rice flours, whereas total anthocyanins were highest in violet, nerone, and black rice flours. FRAP and ORAC antioxidant activities were correlated to phenolic contents and found to be higher in violet rice flours. Metabolomics hi…
Alternariol-induced cytotoxicity in Caco-2 cells. Protective effect of the phenolic fraction from virgin olive oil.
2014
The extra virgin olive oil (EVOO) has been associated to antioxidant effects. The mycotoxin alternariol (AOH) can contaminate olives. The aims of this work were to determine the cytotoxic effects and reactive oxygen species (ROS) produced by AOH, tyrosol and oleuropein (two polyphenols of olive oil) and a real EVOO extract in Caco-2 cells. The MTT assay and the ROS production by the H2-DCFDA probe were used. Results demonstrated that AOH reduces cellular proliferation depending on concentration, whereas tyrosol and oleuropein did not (12.5-100 μM). The combination of AOH + oleuropein (50 μM) increased cell proliferation (24%) whereas, AOH + tyrosol decreased (47%) it. Besides, AOH increased…
Influence of cultivar and concentration of selected phenolic constituents on the in vitro chemiopreventive potential of olive oil extracts.
2011
One of the main olive oil phenolic compounds, hydroxytyrosol (3,4-DHPEA), exerts in vitro chemopreventive activities (antiproliferative and pro-apoptotic) on tumor cells through the accumulation of H2O2 in the culture medium. However, the phenol composition of virgin olive oil is complex, and 3,4-DHPEA is present at low concentrations when compared to other secoiridoids. In this study, the in vitro chemopreventive activities of complex virgin olive oil phenolic extracts (VOO-PE, derived from the four Italian cultivars Nocellara del Belice, Coratina, Ogliarola, and Taggiasca) were compared to each other and related to the amount of the single phenolic constituents. A great chemopreventive po…
Evolution of phenolic compounds virgin olive oil during storage
1997
Phenolic compounds are of fundamental importance to the shelf life of virgin olive oils because of their antioxidative properties. In this paper, the evolution of simple and complex olive oil phenols during 18 mon of storage is studied by high-performance liquid chromatography (HPLC) analysis. The olive oils under examination were from various olive cultivars, harvested in two sectors in the same region at different stages of ripeness. The findings indicate that it is not the variety but rather the ripeness of the olives and the soil and climate that influence the phenol composition of virgin olive oil. In addition, a positive correlation was found between the age of the oils and the tyroso…
Determination of hydroxytyrosol and tyrosol by liquid chromatography for the quality control of cosmetic products based on olive extracts
2014
An analytical method for the simultaneous determination of hydroxytyrosol and tyrosol in different types of olive extract raw materials and cosmetic cream samples has been developed. The determination was performed by liquid chromatography with UV spectrophotometric detection. Different chromatographic parameters, such as mobile phase pH and composition, oven temperature and different sample preparation variables were studied. The best chromatographic separation was obtained under the following conditions: C18 column set at 35°C and isocratic elution of a mixture ethanol: 1% acetic acid solution at pH 5 (5:95, v/v) as mobile phase pumped at 1 mL min(-1). The detection wavelength was set at …