The effects of omega 3 fatty acid supplementation on brain tissue oxidative status in aged wistar rats

Background: The omega 3 fatty acids play an important role in many physiological processes. Their effect is well documented in neurodegenerative diseases and inflammatory diseases. Also, aging as a biophysiological process could be influenced by eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) components of fish oil. However there are not many studies showing the effect of PUFA (polyunsaturated FA) suplementation in eldery brain functions and the response to oxidative strees. The aim of this study was to investigate the effects of dietary omega-3 fatty acid supplementation on levels of lipid peroxidation and oxidant/antioxidant status of brain tissue in aged (24 months old) Wistar rats. Methods: Animals were divided in two groups. Control group (n=8) was fed with standard laboratory food and received water ad libitum. Treated group (n=8) was also fed with standard laboratory food, water ad libitum and received fish oil capsules (EPA+DHA) for 6 weeks. Daily dose was 30mg EPA and 45mg DHA (capsules: 200mg EPA and 300mg DHA; in-house method). At the end of treatment animals were sacrificed and brains were collected and frozen on -80 degrees C. The levels of lipid peroxidation (malondialdehyde - MDA), activity of catalase (CAT) and activity of superoxide dismutase (SOD) were examined in cerebral cortex. Catalase activity was determined by measuring the decrease in absorbance (H2O2 degradation) at 240 nm for 3 min and expressed as U/mg protein. Total SOD (superoxide dismutase) activity was performed at room temperature according to the method of Misra and Fridovich. The extent of lipid peroxidation (LPO) was estimated as the concentration of thiobarbituric acid reactive product malondialdehyde (MDA) by using the method of Aruoma et al. The incorporation of fatty acids in cellular membranes was confirmed by gas chromatography. Results: Our results showed that lipid peroxidation significantly decreased in treated animal group, where MDA concentration was 0.38 +/- 0.001 vs. 0.43 +/- 0.001 nM/ml (p lt 0.05) in control. However SOD activity increased significantly in treated animal group 1.57 +/- 0.24 vs. 4.12 +/- 0.15 U/gHb/L (p lt 0.01) in control. CAT activity decreased in treated group but not significantly. Conclusion: Incorporation of omega-3 fatty acids after their supplementation had beneficial effects on brain tissue. Omega-3 fatty acids increased activity of SOD and decreased lipid peroxidation. Changes in oxidative/antioxidative balance are a result of EPA and DHA effects on lipids and enzymes of antioxidative system. Hippokratia 2012; 16 (3): 214-24

Hemometrijski pristup razvoju kolorimetrijske metode za procenu količine prehrambenih boja u proizvodima od mesa

The aim of this research was to develop a novel colorimetric method based on mathematical models, by multiple linear regression (MLR), from the CIE L*a*b* measurements and data of the HPLC determination of food colorants. Calibration set of 10 production batches of finely grinded cooked sausage with food colorants added was manufactured in industrial conditions as follows: one control batch and 9 products with various quantities of added food colorants: E120 (3.4, 7.5 and 12.5 mg/kg), E 124 (5.0, 15.0, 25.0 mg/kg) and E 129 (5.0, 15.0, 25.0 mg/kg). The estimation of the added food colorants was assessed by measuring L*, a*, b* parameters of cross-section. The quantification of food colorants was achieved by HPLC-PDA. Food colorants were extracted from meat products using Accelerated Solvent Extraction (ASE). Quantification of food colorants was achieved in the range from 1 to 100 mg / kg, and recovery values were from 76.15% to 107.04%, for E 120, from 97.61% to 101.03%, for E 124 and from 99.91% to 101.67%, for E 129. Correlation of the results obtained using HPLC and colorimetric measuring data was assessed by Multiple Linear Regression (MLR). The results from colorimetric and chromatographic determinations in four experimental batches (three batches with different quantities of food colorants and one control batch) were used for calibration. Coefficients of determination (R2) for linear models in experimental batches were 0.954, for E 124, 0.987, for E 120 and 0.993, for E 129. Correlation functions of food colorant quantities and corresponding L*a*b* values were established. The obtained mathematical models were tested for the estimation of the content of dyes in 21 samples of finely grinded cooked sausages purchased in retail stores. Food colorants were confirmed in 20 samples (95.24 %), and one sample (4.76 %) did not contain any of these compounds. Out of the positive samples, sixteen samples (80.00 %) contained E 120, while four samples (20.00 %) contained E 129. Food colorant E124 was not established in any of the analyzed samples. Colorimetric CIE L*a*b* method might be used during sensory evaluation of meat products for the assessment of the added food colorants.Cilj ovog rada je bio da se, merenjem vrednosti parametara boje preseka proizvoda od mesa u CIE (Commission Internationale de l'Eclairage, Međunarodna komisija za osvetljenje) L*a*b* prostoru (L* – svetloća, a* – udeo crvene boje i b* – udeo žute boje) ispita mogućnost procene sadržaja dodate prehrambene boje u proizvodima od mesa. Količina prehrambene boje u uzorcima od mesa određena je metodom visokoefikasne tečne hromatografije sa detekcijom na fotodiodnom sloju (HPLC-PDA), a međusobna zavisnost dobijenih vrednosti i kolorimetrijskih parametara ispitana je višestrukom linearnom regresijom (MLR). Kalibracioni set od 10 proizvodnih partija fino usitnjene barene kobasice, sa tri dodate boje, izrađen je u industrijskim uslovima, i to: kontrolni proizvod bez boje i 9 proizvoda sa različitim količinama dodatih boja E 120 (3,4; 7,5 i 12,5 mg/kg), E 124 (5, 15 i 25 mg/kg) i E 129 (5, 15 i 25 mg/kg). Postavljene su jednačine funkcije zavisnosti količine boje od L*, a* i b* vrednosti. Dobijeni matematički modeli su provereni i primenjeni za procenjivanje sadržaja boje u 21 uzorku fino usitnjenih barenih kobasica sa tržišta. Utvrđeno je da se kolorimetrijskom CIE L*a*b* metodom mogu, u toku senzorskog ocenjivanja boje proizvoda, proceniti količine dodatih boja u proizvodima od mesa i da se ova metoda može primeniti kao komplementarna HPLC-PDA

Chemometric approach in the development of the colorimetric method for the estimation of food colorants in meat products

The aim of this research was to develop a novel colorimetric method based on mathematical models, by multiple linear regression (MLR), from the CIE L*a*b* measurements and data of the HPLC determination of food colorants. Calibration set of 10 production batches of finely grinded cooked sausage with food colorants added was manufactured in industrial conditions as follows: one control batch and 9 products with various quantities of added food colorants: E120 (3.4, 7.5 and 12.5 mg/kg), E 124 (5.0, 15.0, 25.0 mg/kg) and E 129 (5.0, 15.0, 25.0 mg/kg). The estimation of the added food colorants was assessed by measuring L*, a*, b* parameters of cross-section. The quantification of food colorants was achieved by HPLC-PDA. Food colorants were extracted from meat products using Accelerated Solvent Extraction (ASE). Quantification of food colorants was achieved in the range from 1 to 100 mg / kg, and recovery values were from 76.15% to 107.04%, for E 120, from 97.61% to 101.03%, for E 124 and from 99.91% to 101.67%, for E 129. Correlation of the results obtained using HPLC and colorimetric measuring data was assessed by Multiple Linear Regression (MLR). The results from colorimetric and chromatographic determinations in four experimental batches (three batches with different quantities of food colorants and one control batch) were used for calibration. Coefficients of determination (R2) for linear models in experimental batches were 0.954, for E 124, 0.987, for E 120 and 0.993, for E 129. Correlation functions of food colorant quantities and corresponding L*a*b* values were established. The obtained mathematical models were tested for the estimation of the content of dyes in 21 samples of finely grinded cooked sausages purchased in retail stores. Food colorants were confirmed in 20 samples (95.24 %), and one sample (4.76 %) did not contain any of these compounds. Out of the positive samples, sixteen samples (80.00 %) contained E 120, while four samples (20.00 %) contained E 129. Food colorant E124 was not established in any of the analyzed samples. Colorimetric CIE L*a*b* method might be used during sensory evaluation of meat products for the assessment of the added food colorants