The Color of Olive Oils: The Pigments and Their Likely Health Benefits and Visual and Instrumental Methods of Analysis

ABSTRACT: The color of olive oils, and of foods in general, can influence consumer choices to a large extent and can be related to the processing treatments they have undergone. Olive oil color is due to 2 types of pigments, chlorophylls and carotenoids, which are attracting the attention of the scientific community due to the probable health benefits they can provide. Appropriate methodologies for the meaningful definition of the color of olive oil are therefore necessary for various reasons. In this review, we discuss the importance of olive oil color and the applicable legislation and regulation, including sections devoted to the pigments accounting for the growing importance as likely health‐promoting substances. Furthermore, we review in depth the different approaches (visual and instrumental methods) used for color measurements in the last 50 y. Instrumental methods have been shown to be highly appropriate for objective assessments and also for the rapid determination of the pigments.     

Nonmetallic Inclusions in 08Kh18N10T Steel as the Cause of Initiation of Defects in Heat-Exchange Tubes of Steam Generators of Nuclear Power Plants

Materials Science - We present the results of investigation of the microstructure of 08Kh18N10T steel in heat-exchange tubes after their long-term operation in steam generators of WWÉR-1000...     

Regularities of Wear of Metal-Polymer Friction Couples Under the Influence of Tribocurrents

Materials Science - The tribological characteristics of metal-polymer friction couples operating in braking units are studied under the production and laboratory conditions. On the basis of these...     

Improving performance of ZnO flexible dye sensitized solar cell by incorporation of graphene oxide

At today great interest has been paid to hydrogen production by water electrolysis due to their simplicity and low cost. Dye sensitized solar cell are promising devices as renewable electrical power source to achieve water electrolysis because they possess high theoretical efficiency compared with Si based solar cells. In this research, ZnO photo catalyst was modified with graphene oxide (GO) by means of high energy milling. The anode of the flexible dye-sensitized solar cell was fabricated by electrophoretic deposition of the photo catalyst onto flexible electrodes. The obtained materials were characterized by FTIR, XRD, XPS and SEM–EDS. The efficiency and fill factor of ZnO and ZnO–GO cells were estimated from the I–V curve, measured under simulated sunlight. The obtained results demonstrate that ZnO–GO cell have higher efficiency compared with the ZnO cell. The latter can be explained by the better dispersion of ZnO that enlace the dye adsorption onto the fabricated anode and by the presence of GO that improve the absorption of photons from the light.

     

Lipid and fatty acid profiles in rats consuming different high-fat ketogenic diets

High-fat ketogenic diets are used to treat intractable seizures in children, but little is known of the mechanism by which these diets work or whether fats rich in n−3 polyunsaturates might be beneficial. Tissue lipid and fatty acid profiles were determined in rats consuming very high fat (80 weight%), low-carbohydrate ketogenic diets containing either medium-chain triglyceride, flaxseed oil, butter, or an equal combination of these three fat sources. Ketogenic diets containing butter markedly raised liver triglyceride but had no effect on plasma cholesterol. Unlike the other fats, flaxseed oil in the ketogenic diet did not raise brain cholesterol. Brain total and free fatty acid profiles remained similar in all groups, but there was an increase in the proportion of arachidonate in brain total lipids in the medium-chain triglyceride group, while the two groups consuming flaxseed oil had significantly lower arachidonate in brain, liver, and plasma. The very high dietary intake of α-linolenate in the flaxseed group did not change docosahexaenoate levels in the brain. Our previous report based on these diets showed that although ketosis is higher in rats consuming a ketogenic diet based on medium-chain triglyceride oil, seizure resistance in the pentylenetetrazol model is not clearly related to the degree of ketosis achieved. In combination with our present data from the same seizure study, it appears that ketogenic diets with widely differing effects on tissue lipids and fatty acid profiles can confer a similar amount of seizure protection.     

Elastoplastic finite-element analysis of the bearing capacity of beds of reconstructed entities

A method is presented for determination of the coefficients that take into account the increase in angle of internal friction and specific cohesion of silty-clayey soils in predicting variation in the bearing capacity of beds after the long-term effect of the consolidating service-induced loads. __________ Translated From Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 2, Pp. 18–21, March–April, 2007.     

Corrosion properties of austenitic Cr-Mn-Ni-N steels with various manganese concentrations

The structure and corrosion properties of two high-nitrogen 05Kh20AN8MF steels additionally alloyed with 9 and 17% Mn have been studied. Metallographic, X-ray diffraction, and fractographic studies show that both steels have an austenitic structure and high plasticity properties after quenching from 1100 and 1100°C and subsequent aging at 500°C for 2 h. The steel alloyed with 9% Mn and 0.58% V exhibit a higher strength. Both steels have a higher corrosion resistance in a 3.5% NaCl aqueous solution than 12Kh18N9T steel. After aging at 400–600°C, the corrosion rate and the sensitivity to stress corrosion cracking increase.     

Carotenoid pigments: structural and physicochemical considerations

Carotenoid are ubiquitous compounds serving a series of functions that make them special. Thus, they are regarded as essential compounds for life mainly due to the different roles they perform in photosynthesis as we currently know it. For many years, the nutritional relevance ot carotenoids was due to some of them exhibiting vitamin A activity, although the interest in these pigments has expanded dramatically in the last years owing to a large variety of surveys that seem to indicate that they are antioxidant and may be beneficial for the prevention of several chronic non-transmissible human diseases, albeit there is some controversy in this regard. In any case, it is clear that the different functions and effects attributed to these isoprenoids stem from their physical and chemical properties, the latter being due to their chemical structure. Due to the diverse benefitial actions carotenoids are responsible for and, above all, to their nutritional importance, the main objective of this review is to describe such features, whose knowledge is indispensable to have a holistic view of the different roles they play and for the design of new studies.