Search results for " virgin olive oil"

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…

Classification of extra virgin olive oils according to their geographical origin using phenolic compound profiles obtained by capillary electrochroma…

2009

Abstract A simple and reliable method for the evaluation of the phenolic fraction of extra virgin olive oils (EVOO) by capillary electrochromatography (CEC) with UV–Vis detection, using lauryl acrylate (LA) ester-based monolithic columns, has been developed. The percentages of the porogenic solvents in the polymerization mixture, and the mobile phase composition, were optimized. The optimum monolith was obtained with a monomers/porogens ratio of 40:60% (wt/wt) using a LA/1,3-butanediol diacrylate ratio of 70:30% (wt/wt) and a 1,4-butanediol/1-propanol ratio of 25:75% (wt/wt). A satisfactory resolution between the phenolic compounds was achieved in less than 25 min with a 15:85 (v/v) ACN–wat…

Sistema de monitorización en continuo a tiempo real de la concentración de oxígeno durante el batido para la producción de aceite de oliva virgen

2012

During the mechanical extraction process of Virgin Olive Oil (VOO) some important physical phenomena and enzymatic transformations occur which influence the quality of the final product. The control of process parameters is crucial to ensure the quality of VOO, therefore process monitoring and control is a fundamental requirement in the modern VOO processing industry. The present work proposes an innovative Real-Time Monitoring System (RTMS) aimed at continuously measuring the oxygen concentration during the malaxation process in order to establish a correlation with the quality of the final product obtained. This monitoring system is based on an oxygen concentration sensor directly connect…

An oxygen monitoring and control system inside a malaxation machine to improve extra virgin olive oil quality

2013

In recent years, oxygen content regulation during malaxation has been noted as a process parameter. The aim of this study was to identify the optimal time during the malaxation process of the olives of the Sicilian cultivar Nocellara del Belice when the presence of oxygen in the machine headspace activates the enzyme complex in favour of the volatile compounds, without compromising the phenolic composition. During the malaxation process, the atmosphere inside the malaxation machine was modified by blowing pure oxygen from cylinders at specific stages of the process (i.e., 5, 15, 25, and 35 min after the start of malaxation), using a system that allows the automatic and continuous maintenanc…

Effect of various parameters on virgin olive oil stability measured by Rancimat

2007

Characterization of Phenolic and Volatile Compounds of Sicilian Virgin Olive Oils Produced from Native Cultivars

2009

Effects of the foal at the milking and dietary supplementation with extra virgin olive oil on jennet milk production

2009

The effects of the foal at the milking and the extra virgin olive oil supplementation in the diet, on the milk obtained by 12 Ragusana jennets were studied. The jennets were each fed 3.5+1.5 kg/d of concentrate+bran, and hay ad libitum. They were divided into 2 equal groups with one group receiving an additional dietary supplement of 100 ml/d of olive oil. Milk was collected at day 20 post foal- ing and every 15-18 d for 5 times. At each collection period jennets were milked 4-times per day. At 07:30 h foals were separated from the jennets and after a 4 hour interval were milked manually (1MNF;1st milking, foal absent). At the end of the 1MNF, each jennet was milked again, with the foals ke…

Bioactive compounds and quality of extra virgin olive oil

2020

Background: Extra virgin olive oil (EVOO) is responsible for a large part of many health benefits associated to Mediterranean diet as it is a fundamental ingredient of this diet. The peculiarities of this golden, highly valued product are in part due to the requirements that must be met to achieve this title, namely, it has to be obtained using exclusively mechanical procedures, its free acidity cannot be greater than 0.8%, it must not show sensory defects, and it has to possess a fruity taste. Methods: All these characteristics are key factors to EVOO quality, thus the chemical composition of these many health-promoting compounds, such as unsaturated fatty acids (which are also the major c…

Effects of variety and olive ripeness on nutritional quality and oxidative stability of extra virgin olive oils

2004

The composition and the stability to oxidative reactions of Italian extra virgin olive oils, in relation to olive varieties and ripeness, have been studied. Nutritional quality has been evaluated comparing nutrient contents with the recommended daily intake for the Italian population. Oxidative vulnerability has been studied following three different approaches: i) a predictive approach (calculation of the degree of antioxidant protection or DAP index); ii) a descriptive approach (loss of some natural antioxidants during storage); iii) a confirmatory approach (oven test method). This study demonstrated that the olive variety and ripeness degree are important determinants of the nutritional …

Oxidation Processes in Sicilian Olive Oils Investigated by a Combination of Optical and EPR Spectroscopy

2012

:  Extra virgin olive oil (EVOO) is recognized as one of the healthiest foods for its high content of antioxidants, which forestall and slow down radical formation. Free radical-initiated oxidation is considered one of the main causes of rancidity in fats and oils. As a consequence, reliable protocols for the investigation of oil oxidation based on selective, noninvasive, and fast methods are highly desirable. Here we report an experimental approach based on UV-Vis absorbance, steady-state fluorescence, and electron paramagnetic resonance (EPR) spectroscopy for studying oxidation processes induced by temperature for a period up to 35 d on Sicilian EVOO samples. We followed the decrease in β…