Search results for "Tocopherol"

Natural anti-oxidants immobilized onto carbon nanotubes for thermo-oxidation resistant polymer-based nanocomposites

2014

Identification and quantitation of tocopherols, carotenoids and triglycerides in edible Pistacia lentiscus oil from Tunisia

2020

International audience; The fruits of Pistacia lentiscus are a source of a fixed oil used in some forested areas for culinary purposes and in traditional medicines. The aim of this study was to evaluate the levels of tocopherols, carotenoids and triglycerides in this oil using high-performance liquid chromatography (HPLC). The results demonstrated the presence of two vitamin E isomers; α- and γ-tocopherols, at respective concentrations of 119 mg and 23 mg per kg of oil. β-carotene, lutein and zeaxanthin were the principal carotenoid molecules identified. β-carotene was the main molecule present, with a level of 6.13 mg/kg oil. Di-unsaturated triglycerides comprised more than half of the tot…

Tocopherol, fatty acid and phytosterol content in seeds of nine wild taxa of Sicilian Brassica (Cruciferae)

2010

The purpose of this study was to determine tocopherol (Toc), fatty acid and phytosterol content in dry seeds of nine wild taxa of Sicilian Brassica sect. Brassica. Analyses were performed by gas chromatography (GC)-mass spectroscopy (MS). The biochemical analysis of dry seeds showed that in the nine taxa examined, α - and γ -Toc were the major isomers, δ - Toc was present in traces and β -Toc was never found. All taxa had a similar fatty acid composition with C 16:0 (357.2 mg kg − 1 DW), C 18:1 (393.94 mg kg − 1 DW) and C 22:1 (618.29 mg kg − 1 DW) acids present in higher amount. Unsaturated fatty acids (52.5–66.5%) were more abundant than saturated (33.5–47.5%) ones relative to the total f…

Alpha-(13′-hydroxy)-6-hydroxychroman, the main product of alpha-tocopherol metabolism in human hepatocytes, regulates CYP4F2 and PPAR-γ expression

2017

The enzymatic metabolism of vitamin E in liver cells generates long chain metabolites (LCMs) with proposed regulatory activity on inflammatory and atherogenic genes. In this study the LCM formation kinetics was characterized in HepG2 and HepaRG human hepatic cells, supplemented with RRR-α-tocopherol (α-TOH). α-13’OH was the main product of α-TOH metabolism, while α-13’COOH metabolite and the short chain metabolite α-CEHC, were detected only in traces, thus demonstrating the poor efficiency of vitamin E catabolism in these cells. However, this metabolism was significantly simulated when the hepatic cells were challenged with (lipo)toxic agents, such as ethanol or palmitate. Under such condit…

γ-Oryzanol and tocopherol contents in residues of rice bran oil refining

2012

Rice bran oil (RBO) contains significant amounts of the natural antioxidants γ-oryzanol and tocopherols, which are lost to a large degree during oil refining. This results in a number of industrial residues with high contents of these phytochemicals. With the aim of supporting the development of profitable industrial procedures for γ-oryzanol and tocopherol recovery, the contents of these phytochemicals in all the residues produced during RBO refining were evaluated. The samples included residues from the degumming, soap precipitation, bleaching earth filtering, dewaxing and deodorisation distillation steps. The highest phytochemical concentrations were found in the precipitated soap for γ-…

Chemical characterization of traditional varietal olive oils in East of Spain

2013

Abstract The aim of this work has been to characterize the chemical composition of the eight most emblematic varietal olive oils from the West of the Mediterranean Sea. These were classified into two groups according to the International Olive Council (IOC norms): Sweet oils (Farga, Morruda and Serrana) which were compared with Arbequina as standard of the Spanish sweet oils; and bitter–spicy oils (Alfafara, Blanqueta, and Villalonga) that were compared with Picual, considered as the standard of the bitter–spicy olive oils. For the study, sampled trees were chosen in their geographically separated originating areas. They were cultivated in the traditional conditions. The variety of each sam…

Effects of gamma-irradiation on the alpha-tocopherol and fatty acids content of raw unpeeled almond kernels (Prunus dulcis)

2014

Abstract The present study evaluated fatty acid composition and α-tocopherol content of almond as a function of irradiation dose in order to determine dose levels causing minimal undesirable changes to almonds. Raw unpeeled almonds variety Tuono ( Prunus dulcis (Mill.) D. A. Webb) were irradiated using 60 Co source at dose of 0.5, 1.5, 3, 6, 8 and 10 kGy. Both control and irradiated samples were kept frozen and immediately analyzed. The data obtained showed no change in fatty acid compositions up to a dose of 10 kGy; on the contrary, a general trend observed is that increasing the dose of irradiation resulted in the decrease of α-tocopherol content. The study has shown that irradiation is a…

Methacrylate ester-based monolithic columns for nano-LC separation of tocopherols in vegetable oils

2010

The separation and determination of tocopherols (Ts) in vegetable oils by nano-LC chromatography with UV-vis detection using lauryl methacrylate ester-based monolithic columns has been developed. The separation of Ts was optimized in terms of mobile phase composition on the basis of the best compromise among efficiency, resolution and analysis time. Using a mobile phase composed of ACN/methanol/water, an excellent resolution between Ts was achieved within 18 min. The LODs were lower than 0.26 μg/mL, being repeatability values of retention time and peak area below 0.15 and 3.1%, respectively. The method was applied to the quantification of Ts and tocotrienols present in several vegetable oil…

Effect of a Diet Supplemented with alpha-Tocopherol and beta-Carotene on ATP and Antioxidant Levels after Hepatic Ischemia-Reperfusion.

2008

Ischemia-reperfusion injury associated with liver transplantation remains a serious complication in clinical practice. In the present study the effect of intake of alpha-tocopherol or beta-carotene to limit liver injury by oxidative stress in ischemia and reperfusion was explored. Wistar rats were fed with diets enriched with alpha-tocopherol (20 mg/day) or beta-carotene (3 mg/day) for 21 days. After 21 days, their livers were subjected to 15 and 30 min of ischemia and afterwards were reperfused for 60 min. The recovery of levels of ATP during reperfusion was better in the group of rats whose diets were supplemented with alpha-tocopherol or beta-carotene than in the group control. The suppl…

Cholesterol accumulation is increased in macrophages of phospholipid transfer protein-deficient mice: normalization by dietary alpha-tocopherol suppl…

2007

Objective— Phospholipid transfer protein (PLTP) is a multifunctional, extracellular lipid transport protein that plays a major role in lipoprotein metabolism and atherosclerosis. Recent in vivo studies suggested that unlike systemic PLTP, macrophage-derived PLTP would be antiatherogenic. The present study aimed at characterizing the atheroprotective properties of macrophage-derived PLTP. Methods and Results— Peritoneal macrophages were isolated from PLTP-deficient and wild-type mice and their biochemical characteristics were compared. It is shown that macrophages isolated from PLTP-deficient mice have increased basal cholesterol content and accumulate more cholesterol in the presence of LD…