Selenium Content in the Liver of Wistar Rats Fed Diets of Different Fatty Acid Quality.

The purpose of this work was to measure the amounts of selected mineral elements (sodium, calcium, iron, selenium, magnesium, zinc, copper, and manganese) in the liver of Wistar rats and evaluate possible correlations between the levels of these minerals and the lipid metabolism in the studied animals. Three experimental groups each containing six Wistar rats were designed. Each group was fed a different diet. The control group was fed a diet prepared with fresh soybean oil and named control group--CG. The second group (named experimental group B--EGB) and third group (named experimental group C--EGC) were fed a diet containing soybean oil that had been used to fry different foods for four or ten cycles, respectively. The mineral elements in Wistar rat livers were measured by inductively coupled plasma optical emission spectrometry (ICP OES). Only the elements calcium and selenium differed significantly between the control and experimental groups. There was a significant reduction of 33% for Ca and 41% for Se in the EGB in comparison to the control group. The reduction in mineral concentration, especially Se, is the result of interactions with fatty acid metabolism. The animals in the EGC exhibited more intracytoplasmic accumulation of fat and more intense vasodilatation, in relation to the other groups. Collectively, evidence hereby collected suggests that impaired dietary lipid quality in otherwise balanced diets can reduce hepatic Se levels and potentially harm liver function.

20 years of fatty acid analysis by capillary electrophoresis.

A review taking into account the literature reports covering 20 years of fatty acid analysis by capillary electrophoresis is presented. This paper describes the evolution of fatty acid analysis using different CE modes such as capillary zone electrophoresis, non-aqueous capillary electrophoresis, micellar electrokinetic capillary chromatography and microemulsion electrokinetic chromatography employing different detection systems, such as ultraviolet-visible, capacitively coupled contactless conductivity, laser-induced fluorescence and mass spectrometry. In summary, the present review signals that CE seems to be an interesting analytical separation technique that is very useful for screening analysis or quantification of the usual fatty acids present in different matrices, offering short analysis times and a simple sample preparation step as inherent advantages in comparison with the classical methodology, making it a separation technique that is very attractive for quality control in industry and government agencies.

Rapid separation of free fatty acids in vegetable oils by capillary zone electrophoresis.

INTRODUCTION: Olive oil is a very important product to human health since it inhibits formation of free radicals, tumour growth, lesions and inflammatory substances. High concentrations of free fatty acids in olive oils results in lipid deterioration due to oxidative or hydrolytic rancidity. OBJECTIVE: To optimise an alternative capillary zone electrophoresis methodology, under ultraviolet indirect detection and to determine free fatty acids in edible vegetable oils without derivatisation steps in sample preparation. METHODS: The condition used consisted of 15 mm NaH2 PO4 -Na2 HPO4 at pH ~6.86, 4.0 mm of sodium dodecybenzenesulphonate, 8.3 mm of Brij 35®, 45% v/v of acetonitrile and 2.1% of 1-octanol, injection at 12.0 mbar of pressure for 4 s, +19 kV of applied voltage and indirect detection at 224 nm, within an analysis time of 11 min. RESULTS: The capillary zone electrophoresis method was successfully applied to determination of free fatty acids in extra virgin olive oil, virgin olive oil and soybean oil samples. The comparison with the official volumetric titration method showed no significant difference within the 95% confidence interval. CONCLUSION: The main advantage to the proposed method is the possibility to observe the individual amount of the free fatty acids, which would be useful for researchers interested in studying the effect of the free fatty acids profile on oxidative process in food.