Geni Rodrigues Sampaio

The influence of season on the lipid profiles of five commercially important species of Brazilian fish

This study aimed at determining the influence of season (summer and winter) the total lipid, fatty acid and cholesterol contents of five popular fish species: the sardine, Sardinella spp., the croaker Micropogonias furnieri (marine species), the curimbata Prochilodus spp., the tilapia, Oreochromis spp. (fresh water species), and the seabob shrimp, Xiphopenaeus kroyeri. Total lipid analysis was performed by the dry column; fatty acids were determined by gas chromatography and cholesterol was determined by a colorimetric method. Statistical treatment of results showed that sardines collected during winter had the highest lipid contents (10.62). The sardine, the croaker, the tilapia and the curimbata were not influenced by seasonality in terms of their total saturated and unsaturated acid contents. The highest contents of eicosapentanoic acid (3.02 and 1.87%) and docosahexaenoic acid (10.1 and 11.3%) were found in the sardine. The shrimp presented the highest cholesterol contents (165 mg/100 g in summer and 165 mg/100 g in winter).

Dietary Advanced Glycation End Products and Their Role in Health and Disease

Over the past 2 decades there has been increasing evidence supporting an important contribution from food-derived advanced glycation end products (AGEs) to the body pool of AGEs and therefore increased oxidative stress and inflammation, processes that play a major role in the causation of chronic diseases. A 3-d symposium (1st Latin American Symposium of AGEs) to discuss this subject took place in Guanajuato, Mexico, on 1-3 October 2014 with the participation of researchers from several countries. This review is a summary of the different presentations and subjects discussed, and it is divided into 4 sections. The first section deals with current general knowledge about AGEs. The second section dwells on mechanisms of action of AGEs, with special emphasis on the receptor for advanced glycation end products and the potential role of AGEs in neurodegenerative diseases. The third section discusses different approaches to decrease the AGE burden. The last section discusses current methodologic problems with measurement of AGEs in different samples. The subject under discussion is complex and extensive and cannot be completely covered in a short review. Therefore, some areas of interest have been left out because of space. However, we hope this review illustrates currently known facts about dietary AGEs as well as pointing out areas that require further research.

Effect of natural antioxidant combinations on lipid oxidation in cooked chicken meat during refrigerated storage

The effect of combinations of sage, oregano and honey on lipid oxidation in cooked chicken meat during refrigeration at 4°C for 96h was determined. Chicken samples (thigh and breast) were then separated into five groups: control; butylated hydroxytoluene; oregano+sage; oregano+sage+5%honey and oregano+sage+10%honey. Quantitative measurements of thiobarbituric acid reactive substances, conjugated dienes, hexanal, fatty acids, cholesterol and cholesterol oxides were used as indicators of lipid oxidation. Acceptability and preference were also evaluated. The effectiveness of the natural antioxidants for reducing the velocity of lipid oxidation in cooked chicken thigh and breast was demonstrated after 48 and 96h of refrigeration at 4°C. The treatments that presented the lowest hexanal values after 96h of refrigeration were oregano+sage+5%honey and oregano+sage+10%honey. Only traces of free cholesterol oxides were found (25-OH, 7-k, 7α-OH and 7β-OH). The natural antioxidants protected cooked chicken meat from oxidation processes and resulted in great acceptability.

Oxidation of Cholesterol in Foods and Its Importance for Human Health

Cholesterol oxidation products are present in different biological pathways and in oxidized cholesterol-containing food. More than 70 molecules have been identified and most of them present cytotoxic, atherogenic, mutagenic, and carcinogenic effects. They can change important characteristics of the cellular membrane and inhibit the biosynthesis of several molecules. Foods of animal origin can develop these derivatives by the action of oxygen, heat, polyunsaturated fatty acids, water, pH, radiation, and inadequate packaging and storage, affecting their quality and exposing consumers to potential health problems. Despite the interest in cholesterol oxidation products, safe biological levels for them have not yet been established. The purpose of this review is to examine cholesterol oxidation products in foods and examine their importance for human health.

Influence of home cooking conditions on Maillard reaction products in beef.

The influence of home cooking methods on the generation of Maillard reaction products (MRP) in beef was investigated. Grilling and frying hamburgers to an internal temperature below 90 °C mainly generated furosine. When the temperature reached 90 °C and 100 °C, furosine content decreased by 36% and fluorescent compounds increased by up to 98%. Baking meat at 300 °C, the most severe heat treatment studied, resulted in the formation of carboxymethyllysine. Boiling in water caused very low MRP formation. Acrylamide concentrations in grilled, fried or baked meat were extremely low. Home cooking conditions leading to low MRP generation and pleasant colours were obtained and could be used to guide diabetic and chronic renal patients on how to reduce their carboxymethyllysine intake.

Influence of seasonality on the chemical composition of oysters (Crassostrea rhizophorae).

This paper aimed to evaluate the influence of seasonality on the chemical composition of oysters (Crassostrea rhizophorae). Samples were collected during summer and winter from the estuary and lagoon complex of the municipality of Barra de São Miguel, Alagoas, Brazil. Statistical differences (p<0.05) between summer and winter were observed in relation to chemical composition. The oysters cultivated in the winter presented some nutritional advantages because of the higher levels of proteins and functional nutrients, such as the eicosapentaenoic-docosahexaenoic acid combination and percentages of polyunsaturated fatty acids (n-3 and n-6), and the lower levels of saturated fatty acids. Therefore, the animals in winter presented a higher content of cholesterol oxides. The levels of cholesterol oxides found in these products during winter may encourage researchers to investigate the composition of oysters cultivated in different climates all over the world.

Development and Validation of Methods for the Extraction of Phenolic Acids from Plasma, Urine, and Liver and Analysis by UPLC-MS

This study developed and validated a method for the extraction and determination of 11 phenolic acids in rat plasma, urine, and liver by ultraperformance liquid chromatography-mass spectrometry (UPLC-MS). A system suitability test (instrumental linearity, area, and retention time precision) was performed and recovery, intraday and between-day precisions, detection limits (LOD), and quantification limits (LOQ) were determined for all compounds in each biological matrix. Recoveries varied between 88 and 117% in plasma, between 87 and 102% in urine, and between 38 and 100% in liver. Precision was higher than 13.7% intraday and 14.0% interday in all matrices, at three concentration levels. To demonstrate the applicability, the method was used to estimate the concentrations of phenolic acids in samples from animals that received 5-caffeoylquinic acid (5-CQA) by gavage. The excellent validation results and the applicability of the method to real samples confirmed the suitability for studies on absorption, bioavailability, and pharmacokinetics of phenolic acids derived from foods rich in phenolic compounds.

Fish oil and vitamin E change lipid profiles and anti-LDL-antibodies in two different ethnic groups of women transitioning through menopause

BACKGROUND studies have investigated the relationship between the transition through menopause and cardiovascular diseases. White population, generally, have lower levels of traditional coronary heart risk factors, particularly dyslipidemia, hypertension, obesity, and diabetes, and lower rates of coronary heart disease mortality, than black population. Furthermore many studies have shown the cardioprotective and anti-inflammatory effects of omega-3 polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid) of marine origin. The aim of this study was to investigate the effect of omega-3 supplementation, combined or not with vitamin E, on oxidative biomarkers and lipid profiles in nonwhite and white women with dyslipidemia transitioning through menopause. METHODS a randomized, double-blind, placebo-controlled trial was conducted. Seventy-four eligible women were assigned to receive: fish oil, fish oil plus vitamin E and placebo for three months. At baseline, 45 and 90 days blood sample for biochemical variables and biomarkers of oxidative stress were taken. Socioeconomic and lifestyle variables were collected with standardized questionnaires. RESULTS after 90 days the fish oil plus vitamin E treated group had a significant decrease in total cholesterol and LDL-C. Furthermore, there was a decrease in anti- LDL- autoantibodies after 45 days. Plasma TBARS concentrations were increased after 90 days in the group receiving only fish oil when compared to the placebo and fish oil-vitamin E groups. All of the effects observed were independent of ethnic group. CONCLUSION supplementation with fish oil and vitamin E reduced total cholesterol and LDL-C, but had opposite effects on oxidative stress compared to supplementation with fish oil alone.

Polycyclic aromatic hydrocarbons content and fatty acids profile in coconut, safflower, evening primrose and linseed oils

This study aimed at evaluating the polycyclic aromatic hydrocarbons (PAHs) contamination of commercial vegetable oils and examined the identity through the fatty acids profiles. Coconut, safflower, evening primrose, and linseed oils marketed in São Paulo (Brazil) were investigated totaling 69 samples. Four PAHs, benzo[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF), and benzo[a]pyrene (BaP), were detected in 96% of the samples at individual levels ranging from not detected to 14.99 μg kg-1. Chrysene was the abundant hydrocarbon found among all types of oils, with the highest median values. The results of the fatty acid profiles revealed that 43% showed different profiles according to the ones on their labels, with a higher incidence of adulteration of evening primrose oils. The maximum tolerable limits by European Regulation No. 835/2011 were exceeded for BaP in 12%, and for total 4 PAHs in 28%, with a greater contribution of adulterated samples.

Optimization and validation of a method using UHPLC-fluorescence for the analysis of polycyclic aromatic hydrocarbons in cold-pressed vegetable oils

Among the different food categories, the oils and fats are important sources of exposure to polycyclic aromatic hydrocarbons (PAHs), a group of organic chemical contaminants. The use of a validated method is essential to obtain reliable analytical results since the legislation establishes maximum limits in different foods. The objective of this study was to optimize and validate a method for the quantification of four PAHs [benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(a)pyrene] in vegetable oils. The samples were submitted to liquid-liquid extraction, followed by solid-phase extraction, and analyzed by ultra-high performance liquid chromatography. Under the optimized conditions, the validation parameters were evaluated according to the INMETRO Guidelines: linearity (r2 >0.99), selectivity (no matrix interference), limits of detection (0.08-0.30μgkg-1) and quantification (0.25-1.00μgkg-1), recovery (80.13-100.04%), repeatability and intermediate precision (<10% RSD). The method was found to be adequate for routine analysis of PAHs in the vegetable oils evaluated.