Lipídios estruturados obtidos a partir da mistura de gordura de frango, sua estearina e triacilgliceróis de cadeia média: I- Composição em ácidos graxos e em triacilgliceróis

The purpose of this study is to analyze the interactions that occur in binary and ternary fat blends between medium and long chain triacylglycerols and their structured lipids obtained by chemical interesterification through the analysis of their physico-chemical properties. The synthesized structured triacylglycerols presented from 14.8 to 58.4% medium chain fatty acids, from 15.7 to 37.2% saturated fatty acids, from 19.2 to 47.5% monounsaturated fatty acids, and from 6.7 to 15.2% essential fatty acids. Chemical interesterification modified the behavior of binary and ternary mixtures and new types of triacylglycerol groups were formed.

Comparison of gas chromatographic and gravimetric methods for quantization of total fat and fatty acids in foodstuffs

Different methods to determine total fat (TF) and fatty acids (FA), including trans fatty acids (TFA), in diverse foodstuffs were evaluated, incorporating gravimetric methods and gas chromatography with flame ionization detector (GC/FID), in accordance with a modified AOAC 996.06 method. Concentrations of TF and FA obtained through these different procedures diverged (p< 0.05) and TFA concentrations varied beyond 20 % of the reference values. The modified AOAC 996.06 method satisfied both accuracy and precision, was fast and employed small amounts of low toxicity solvents. Therefore, the results showed that this methodology is viable to be adopted in Brazil for nutritional labeling purposes.

Electron paramagnetic resonance (EPR) spectral components of spin-labeled lipids in saturated phospholipid bilayers: effect of cholesterol

Electron paramagnetic resonance (EPR) spectroscopy was used to study the main structural accommodations of spin labels in bilayers of saturated phosphatidylcholines with acyl chain lengths ranging from 16 to 22 carbon atoms. EPR spectra allowed the identification of two distinct spectral components in thermodynamic equilibrium at temperatures below and above the main phase transition. An accurate analysis of EPR spectra, using two fitting programs, enabled determination of the thermodynamic profile for these major probe accommodations. Focusing the analysis on two-component EPR spectra of a spin-labeled lipid, the influence of 40 mol % cholesterol in DPPC was studied.

Simultaneous and accurate determination of water- and fat-soluble vitamins in multivitamin tablets by using an RP-HPLC method

In the present study, a reversed-phase high-performance liquid chromatographic (RP-HPLC) procedure was developed and validated for the simultaneous determination of seven water-soluble vitamins (thiamine, riboflavin, niacin, cyanocobalamin, ascorbic acid, folic acid, and p-aminobenzoic acid) and four fat-soluble vitamins (retinol acetate, cholecalciferol, α-tocopherol, and phytonadione) in multivitamin tablets. The linearity of the method was excellent (R² > 0.999) over the concentration range of 10 - 500 ng mL-1. The statistical evaluation of the method was carried out by performing the intra- and inter-day precision. The accuracy of the method was tested by measuring the average recovery; values ranged between 87.4% and 98.5% and were acceptable quantitative results that corresponded with the label claims.

Simultaneous analysis of saturated and unsaturated fatty acids present in pequi fruits by capillary electrophoresis

In the current study, an alternative method has been proposed for simultaneous analysis of palmitic, stearic, oleic, linoleic, and linolenic acids by capillary zone electrophoresis (CZE) using indirect detection. The background electrolyte (BGE) used for the analysis of these fatty acids (FAs) consisted of 15.0 mmol L−1 NaH2PO4/Na2HPO4 at pH 6.86, 4.0 mmol L−1 SDBS, 8.3 mmol L−1 Brij 35, 45% v/v acetonitrile (can), and 2.1% n-octanol. The FAs quantification of FAs was performed using a response factor approach, which provided a high analytical throughput for the real sample. The CZE method, which was applied successfully for the analysis of pequi pulp, has advantages such as short analysis time, absence of lipid fraction extraction and derivatization steps, and no significant difference in the 95% confidence intervals for FA quantification results, compared to the gas chromatography official method (AOCS Ce 1h-05).

Selection of microorganisms producer of lipase for fat removal from biodiesel purification water

The objective this study has been the selection of lipase productor microorganism, for removal of oils and grease, in the pre-treatment of biodiesel wastewater washing. For this, analyses of the physicist-chemistries characteristics had been made with the wastewater of the biodiesel washing, and then it had been isolated and chosen, by means of determinations of the lipase activity. Following, it was made a test of fat biodegradation, in the conditions: pH (5.95), temperature (35 ºC), rotation (180 rpm) and ammonium sulfate as nitrogen source (3 g L-1) and establishing as variable the two microorganism preselected and the time (24; 48; 72; 96 and 120 h). The biodiesel purification wastewater had presented high potential of environmental impact, presenting a concentration of O of 6.76 g L-1. From the six isolated microbiological cultures, two microorganisms (A and B) had been selected, with enzymatic index of 0.56 and 0.57, respectively. The treatment of the wastewater using the isolated microorganism (Klebsiella oxytoca) had 80% of the fatty removal in 48 h.

Effect of dietary (n-3) highly unsaturated fatty acids on growth and survival of fat snook (Centropomus parallelus, Pisces: Centropomidae) larvae during first feeding

The effect of rotifers, Brachionus rotundiformis (S-type), fed three different diets: A (rotifer fed Nannochloropsis oculata), B (rotifer fed N. oculata and baker's yeast, 1:1), and C (rotifer fed N. oculata and baker's yeast, 1:1, and enriched with Selcoâ), was evaluated based on the survival, growth and swim bladder inflation rate of fat snook larvae. Rotifers of treatment A had higher levels (4.58 mg/g dry weight) of eicosapentaenoic acid (EPA) than B (1.81 mg/g dry weight), and similar levels (0.04 and 0.06 mg/g dry weight, respectively) of docosahexaenoic acid (DHA). Rotifers of treatment C had the highest levels of EPA (13.2 mg/g dry weight) and DHA (6.08 mg/g dry weight). Fat snook eggs were obtained by spawning induction with human chorionic gonadotropin. Thirty hours after hatching, 30 larvae/liter were stocked in black cylindric-conical tanks (36-liter capacity). After 14 days of culture, there were no significant differences among treatments. Mean standard length was 3.13 mm for treatment A, 3.17 mm for B, and 3.39 mm for C. Mean survival rates were very low (2.7% for treatment A, 2.3% for B, and 1.8% for C). Swim bladder inflation rates were 34.7% for treatment A, 27.1% for B, and 11.9% for C. The lack of differences in growth and survival among treatments showed that the improvement of the dietary value of rotifer may not have been sufficient to solve the problem of larval rearing. Some other factor, probably pertaining to the quality of the larvae, may have negatively influenced survival.

Body fat and cholecalciferol supplementation in elderly homebound individuals

Vitamin D deficiency, observed mainly in the geriatric population, is responsible for loss of bone mass and increased risk of bone fractures. Currently, recommended doses of cholecalciferol are advised, but since there are few studies evaluating the factors that influence the serum levels of 25-hydroxyvitamin D (25(OH)D) following supplementation, we analyzed the relationship between the increase in serum 25(OH)D after supplementation and body fat. We studied a group of 42 homebound elderly subjects over 65 years old (31 women) in order to assess whether there is a need for adjustment of the doses of cholecalciferol administered to this group according to their adipose mass. Baseline measurements of 25(OH)D, intact parathyroid hormone and bone remodeling markers (osteocalcin and carboxy-terminal fraction of type 1 collagen) were performed. Percent body fat was measured by dual-energy X-ray absorptiometry. The patients were divided into three groups according to their percent body fat index and were treated with cholecalciferol, 7,000 IU a week, for 12 weeks. The increases in serum levels of 25(OH)D were similar for all groups, averaging 7.46 ng/mL (P < 0.05). It is noteworthy that this increase only shifted these patients from the insufficiency category to hypovitaminosis. Peak levels of 25(OH)D were attained after only 6 weeks of treatment. This study demonstrated that adipose tissue mass does not influence the elevation of 25(OH)D levels following vitamin D supplementation, suggesting that there is no need to adjust vitamin D dose according to body fat in elderly homebound individuals.

Coronary fat content evaluated by morphometry in patients with severe atherosclerosis has no relation with serum lipid levels

The relationship between lipid serum levels and coronary atherosclerotic plaque fat content was studied in 51 necropsy patients. Serum lipids were measured by standard techniques, during life, in the absence of lipid-lowering drugs. Intima, intimal fat and media areas were measured using a computerized system in cryosections of the odd segments of the right, anterior descending and circumflex coronary arteries stained with Sudan-IV. Mean intimal and lipid areas were 5.74 ± 1.98 and 1.22 ± 0.55 mm² (22.12 ± 8.48%) in 26 cases with high cholesterol (³200 mg/dL) and 4.98 ± 1.94 and 1.16 ± 0.66 mm² (22.75 ± 9.06%) in 25 cases with normal cholesterol (<200 mg/dL; P > 0.05). Patients with high levels of low-density lipoprotein (³130 mg/dL, N = 15) had a higher intima/media area ratio than those with normal levels of low-density lipoprotein (<130 mg/dL, N = 13, P < 0.01). No significant difference in the morphometrical variables was found in groups with high or low serum levels of triglycerides (³200 mg/dL, N = 13 vs <200 mg/dL, N = 36) or high-density lipoprotein (³35 mg/dL, N = 11 vs <35 mg/dL, N = 17). The association between the morphological measurements and serum levels of cholesterol, its fractions, and triglycerides was also tested and the correlation coefficients were low. Although high cholesterol is a risk factor, we show here that in patients with severe atherosclerosis blood cholesterol and triglyceride levels seem to have little influence on coronary lipid content, indicating that other factors may contribute to arterial lipid deposition and plaque formation.

Beneficial effects of exercise training (treadmill) on insulin resistance and nonalcoholic fatty liver disease in high-fat fed C57BL/6 mice

C57BL/6 mice develop signs and symptoms comparable, in part, to the human metabolic syndrome. The objective of the present study was to evaluate the effects of exercise training on carbohydrate metabolism, lipid profile, visceral adiposity, pancreatic islet alterations, and nonalcoholic fatty liver disease in C57BL/6 mice. Animals were fed one of two diets during an 8-week period: standard (SC, N = 12) or very high-fat (HF, N = 24) chow. An exercise training protocol (treadmill) was then established and mice were divided into SC and HF sedentary (SC-Sed, HF-Sed), exercised groups (SC-Ex, HF-Ex), or switched from HF to SC (HF/SC-Sed and HF/SC-Ex). HF/HF-Sed mice had the greatest body mass (65% more than SC/SC-Sed; P < 0.0001), and exercise reduced it by 23% (P < 0.0001). Hepatic enzymes ALP (+80%), ALT (+100%) and AST (+70%) were higher in HF/HF mice than in matched SC/SC. Plasma insulin was higher in both the HF/HF-Sed and HF/SC-Sed groups than in the matched exercised groups (+85%; P < 0.001). Pancreatic islets, adipocytes and liver structure were greatly affected by HF, ultimately resulting in islet β-cell hypertrophy and severe liver steatosis. The HF group had larger islets than the SC/SC group (+220%; P < 0.0001), and exercise significantly reduced liver steatosis and islet size in HF. Exercise attenuated all the changes due to HF, and the effects were more pronounced in exercised mice switched from an HF to an SC diet. Exercise improved the lipid profile by reducing body weight gain, visceral adiposity, insulin resistance, islet alterations, and fatty liver, contributing to obesity and steatohepatitis control.

Effects of chronic treadmill training on body mass gain and visceral fat accumulation in overfed rats

This study evaluated the effects of chronic treadmill training on body mass gain and visceral fat accumulation in overfed rats. Overfeeding was induced by reducing the litter size to 3 male pups per mother during the suckling period. The litter size of control rats was adjusted to 10 male pups per mother. Seven weeks after birth overfed and normally fed rats were selected and assigned to a sedentary protocol or to a low-intensity treadmill training protocol (60 min, 5 times/week, for 9 weeks). Four groups (overfed sedentary, N = 23; normally fed sedentary, N = 32; overfed exercised, N = 18, and normally fed exercised, N = 18) were evaluated at 18 weeks. Data are reported as means ± SEM. Initial body weight was similar in control and overfed rats [8.0 ± 0.2 g (N = 42) vs 8.0 ± 0.1 g (N = 50); P > 0.05] and body weight gain during the suckling period was higher in the overfed rats (30.6 ± 0.9 vs 23.1 ± 0.3 g; P < 0.05). Exercise attenuated the body weight gain of overfed compared to sedentary rats (505 ± 14 vs 537 ± 12 g; P < 0.05). The sedentary overfed rats showed higher visceral fat weight compared to normally fed animals (31.22 ± 2.08 vs 21.94 ± 1.76 g; P < 0.05). Exercise reduced visceral fat by 36.5% in normally fed rats and by 35.7% in overfed rats. Exercise attenuated obesity in overfed rats and induced an important reduction of visceral fat.

Anthropometric midarm measurements can detect systemic fat-free mass depletion in patients with chronic obstructive pulmonary disease

Our objective was to determine whether anthropometric measurements of the midarm (MA) could identify subjects with whole body fat-free mass (FFM) depletion. Fifty-five patients (31% females; age: 64.6 ± 9.3 years) with mild/very severe chronic obstructive pulmonary disease (COPD), 18 smokers without COPD (39% females; age: 49.0 ± 7.3 years) and 23 never smoked controls (57% females; age: 48.2 ± 9.6 years) were evaluated. Spirometry, muscle strength and MA circumference were measured. MA muscle area was estimated by anthropometry and MA cross-sectional area by computerized tomography (CT) scan. Bioelectrical impedance was used as the reference method for FFM. MA circumference and MA muscle area correlated with FFM and biceps and triceps strength. Receiver operating characteristic curve analysis showed that MA circumference and MA muscle area cut-off points presented sensitivity and specificity >82% to discriminate FFM-depleted subjects. CT scan measurements did not provide improved sensitivity or specificity. For all groups, there was no significant statistical difference between MA muscle area [35.2 (29.3-45.0) cm²] and MA cross-sectional area values [36.4 (28.5-43.3) cm²] and the linear correlation coefficient between tests was r = 0.77 (P < 0.001). However, Bland-Altman plots revealed wide 95% limits of agreement (-14.7 to 15.0 cm²) between anthropometric and CT scan measurements. Anthropometric MA measurements may provide useful information for identifying subjects with whole body FFM depletion. This is a low-cost technique and can be used in a wider patient population to identify those likely to benefit from a complete body composition evaluation.

Effect of silybin on high-fat-induced fatty liver in rats

Silybin, a natural antioxidant, has been traditionally used against a variety of liver ailments. To investigate its effect and the underlying mechanisms of action on non-alcoholic fatty liver in rats, we used 60 4-6-week-old male Sprague-Dawley rats to establish fatty liver models by feeding a high-fat diet for 6 weeks. Hepatic enzyme, serum lipid levels, oxidative production, mitochondrial membrane fluidity, homeostasis model assessment-insulin resistance index (HOMA-IR), gene and protein expression of adiponectin, and resistin were evaluated by biochemical, reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. Compared with the model group, silybin treatment (26.25 mg·kg-1·day-1, started at the beginning of the protocol) significantly protected against high-fat-induced fatty liver by stabilizing mitochondrial membrane fluidity, reducing serum content of alanine aminotransferase (ALT) from 450 to 304 U/L, decreasing hepatic malondialdehyde (MDA) from 1.24 to 0.93 nmol/mg protein, but increasing superoxide dismutase (SOD) and glutathione (GSH) levels from 8.03 to 9.31 U/mg protein and from 3.65 to 4.52 nmol/mg protein, respectively. Moreover, silybin enhanced the gene and protein expression of adiponectin from 215.95 to 552.40, but inhibited that of resistin from 0.118 to 0.018. Compared to rosiglitazone (0.5 mg·kg-1·day-1, started at the beginning of the protocol), silybin was effective in stabilizing mitochondrial membrane fluidity, reducing SOD as well as ALT, and regulating gene and protein expression of adiponectin (P < 0.05). These results suggest that mitochondrial membrane stabilization, oxidative stress inhibition, as well as improved insulin resistance, may be the essential mechanisms for the hepatoprotective effect of silybin on non-alcoholic fatty liver disease in rats. Silybin was more effective than rosiglitazone in terms of maintaining mitochondrial membrane fluidity and reducing oxidative stress.