92 resultados para Total polyphenols
Acute high-intensity exercise with low energy expenditure reduced LDL-c and total cholesterol in men
Resumo:
A reduction in LDL cholesterol and an increase in HDL cholesterol levels are clinically relevant parameters for the treatment of dyslipidaemia, and exercise is often recommended as an intervention. This study aimed to examine the effects of acute, high-intensity exercise (similar to 90% VO(2max)) and varying carbohydrate levels (control, low and high) on the blood lipid profile. Six male subjects were distributed randomly into exercise groups, based on the carbohydrate diets (control, low and high) to which the subjects were restricted before each exercise session. The lipid profile (triglycerides, VLDL, HDL cholesterol, LDL cholesterol and total cholesterol) was determined at rest, and immediately and 1 h after exercise bouts. There were no changes in the time exhaustion (8.00 +/- A 1.83; 7.82 +/- A 2.66; and 9.09 +/- A 3.51 min) and energy expenditure (496.0 +/- A 224.8; 411.5 +/- A 223.1; and 592.1 +/- A 369.9 kJ) parameters with the three varying carbohydrate intake (control, low and high). Glucose and insulin levels did not show time-dependent changes under the different conditions (P > 0.05). Total cholesterol and LDL cholesterol were reduced after the exhaustion and 1 h recovery periods when compared with rest periods only in the control carbohydrate intake group (P < 0.05), although this relation failed when the diet was manipulated. These results indicate that acute, high-intensity exercise with low energy expenditure induces changes in the cholesterol profile, and that influences of carbohydrate level corresponding to these modifications fail when carbohydrate (low and high) intake is manipulated.
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Banana, an important component in the diet of the global population, is one of the most consumed fruits in the world. This fruit is also very favorable to industry processes (e. g., fermented beverages) due to its rich content on soluble solids and minerals, with low acidity. The main objective of this work was to evaluate the influence of factors such as banana weight and extraction time during a hot aqueous extraction process on the total soluble solids content of banana. The extract is to be used by the food and beverage industries. The experiments were performed with 105 mL of water, considering the moisture of the ripe banana (65%). Total sugar concentrations were obtained in a beer analyzer and the result expressed in degrees Plato (degrees P, which is the weight of the extract or the sugar equivalent in 100 g solution at 20 degrees C), aiming at facilitating the use of these results by the beverage industries. After previous studies of characterization of the fruit and of ripening performance, a 2(2) full-factorial star design was carried out, and a model was developed to describe the behavior of the dependent variable (total soluble solids) as a function of the factors (banana weight and extraction time), indicating as optimum conditions for extraction 38.5 g of banana at 39.7 min.
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In this paper, we address the problem of scheduling jobs in a no-wait flowshop with the objective of minimising the total completion time. This problem is well-known for being nondeterministic polynomial-time hard, and therefore, most contributions to the topic focus on developing algorithms able to obtain good approximate solutions for the problem in a short CPU time. More specifically, there are various constructive heuristics available for the problem [such as the ones by Rajendran and Chaudhuri (Nav Res Logist 37: 695-705, 1990); Bertolissi (J Mater Process Technol 107: 459-465, 2000), Aldowaisan and Allahverdi (Omega 32: 345-352, 2004) and the Chins heuristic by Fink and Voa (Eur J Operat Res 151: 400-414, 2003)], as well as a successful local search procedure (Pilot-1-Chins). We propose a new constructive heuristic based on an analogy with the two-machine problem in order to select the candidate to be appended in the partial schedule. The myopic behaviour of the heuristic is tempered by exploring the neighbourhood of the so-obtained partial schedules. The computational results indicate that the proposed heuristic outperforms existing ones in terms of quality of the solution obtained and equals the performance of the time-consuming Pilot-1-Chins.
Resumo:
This paper addresses the non-preemptive single machine scheduling problem to minimize total tardiness. We are interested in the online version of this problem, where orders arrive at the system at random times. Jobs have to be scheduled without knowledge of what jobs will come afterwards. The processing times and the due dates become known when the order is placed. The order release date occurs only at the beginning of periodic intervals. A customized approximate dynamic programming method is introduced for this problem. The authors also present numerical experiments that assess the reliability of the new approach and show that it performs better than a myopic policy.
Resumo:
The flowshop scheduling problem with blocking in-process is addressed in this paper. In this environment, there are no buffers between successive machines: therefore intermediate queues of jobs waiting in the system for their next operations are not allowed. Heuristic approaches are proposed to minimize the total tardiness criterion. A constructive heuristic that explores specific characteristics of the problem is presented. Moreover, a GRASP-based heuristic is proposed and Coupled with a path relinking strategy to search for better outcomes. Computational tests are presented and the comparisons made with an adaptation of the NEH algorithm and with a branch-and-bound algorithm indicate that the new approaches are promising. (c) 2007 Elsevier Ltd. All rights reserved.
Resumo:
Whole rice has been widely studied due to the abundance of bioactive compounds in its pericarp. Some of the beneficial effects of these compounds on human health have been attributed to their antioxidant and other biological activities, such as enzyme inhibition. In this work, we evaluated the contents of total, soluble and insoluble phenolic compounds of 6 red and 10 non-pigmented genotypes of whole rice as well as their inhibitory effect on the activity of angiotensin I-converting enzyme (ACE). The effects of cooking on phenolics and their inhibitory activities were also investigated. Red genotypes showed high content of phenolics, mainly soluble compounds, at an average of 409.7 mg ferulic acid eq./100 g, whereas overall lower average levels (99.4 mg ferulic acid eq./100 g) at an approximate soluble/insoluble compound ratio of 1:1 were observed in non-pigmented rice. Pigmented rice displayed a greater inhibitory effect on ACE than non-pigmented rice. In fact, a significant correlation between the content of soluble phenolics and ACE inhibition was observed (r = 0.8985, p < 0.05). In addition to significantly reducing the levels of total phenolics and ACE inhibition, cooking altered the soluble/insoluble compound ratio, especially among red rice genotypes. (C) 2011 Elsevier Ltd. All rights reserved.
Resumo:
The effects of different cooking conditions such as soaking, atmospheric (100 degrees C) or pressure boiling (121 degrees C), and draining of cooking water following thermal treatment on phenolic compounds and the DPPH radical scavenging capacity from two selected Brazilian bean cultivars (black and yellow-brown seed coat color) were investigated using a factorial design (2(3)). Factors that significantly reduced the total phenolic contents and antioxidant capacity in both cultivars were the soaking and draining stage. Independent of cooking temperature, total phenolics and antioxidant capacities were enhanced in treatments without soaking and where cooking water was not discarded, and this was likely linked to an increase of specific phenolic compounds detected by high performance liquid chromatography such as flavonols and free phenolic acids in both cultivars. Cooking of beans either at 100 or 121 degrees C, without a soaking stage and keeping the cooking water, would be recommendable for retaining antioxidant phenolic compounds.
Resumo:
The present study was designed to evaluate the possible effect of the consumption of blackberry juices (BJ) prepared with water (BJW) and defatted milk (BJM) on the plasma antioxidant capacity and the. enzymatic and nonenzymatic antioxidants. A significant (p < 0.05) increase in the ascorbic acid content in the plasma was observed after intake of both BJs. However, no changes were observed in the plasma urate and a-tocopherol levels. An increase on the plasma antioxidant capacity, by ORAC assay, was observed only after consumption of BJW but not statistically significant. Plasma antioxidant capacity had a good positive correlation with ascorbic acid (r = 0.93) and a negative correlation with urate level (r = -0.79). No correlation was observed between antioxidant capacity and total cyanidin or total ellagic acid contents. Further, it was observed that plasma catalase increased following intake of BJ`s. No change was observed on the plasma and erythrocyte CAT and glutathione peroxidase activities. A significant decrease (p < 0.05) in the urinary antioxidant capacity between 1 and 4 h after intake of both BJs was observed. A good correlation was observed between total antioxidant capacity and urate and total cyanidin levels. These results suggested association between anthocyanin levels and CAT and a good correlation between antioxidant capacity and ascorbic acid in the human plasma after intake of BJs. Follow-up studies investigating the antioxidant properties and health benefits are necessary to demonstrate the health benefits of polyphenols.
Resumo:
Strawberries are one of the most popular edible fruits in Brazil and their consumption has increased with the development of new varieties available at almost all seasons. Fruit of seven full-ripened strawberry cultivars (Dover, Camp Dover, Camarosa, Sweet Charlie, Toyonoka, Oso Grande and Piedade) were characterized in relation to the total phenolics, vitamin C, flavonoids, free and total ellagic acid contents and antioxidant capacity. Camp Dover had the lowest values for anthocyanins and total phenolics but the highest total flavonoid content. Dover presented the highest anthocyanin, total phenolics and ellagic acid contents and also elevated antioxidant capacity. The best conditions for the determination of the total ellagic acid content in strawberries were also optimized and the results showed that the extraction with 80% acetone, and hydrolysis using 2 N TFA at 120 degrees C for 60 min allowed a 99% recovery. (C) 2007 Elsevier Ltd. All rights reserved.
Resumo:
Background: Cobalamin (Cbl) and folate deficiencies and gene polymorphism of key enzymes or carriers can impair homocysteine metabolism and may change the serum values of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH). We investigated the nutritional and genetic determinants for total homocysteine (tHcy), methylmalonic acid (MMA) and SAM/SAH in healthy Brazilian childbearing-age women. Methods: Serum concentrations of Cbl, folate, red blood cell folate, ferritin, tHcy, MMA, SAM, SAH and other metabolites were measured in 102 healthy unrelated women. The genotypes for MTHFR C677T, MTHFR A1298C, MTR A2756G, MTRR A66G, TC2 C776G, TC2 A67G and RFCI A80G gene polymorphisms were identified by PCR-RFLP. Results: Serum folate and Cbl were inversely correlated with tHcy and serum MMA, respectively. Cbl deficiency was associated with increased MMA and reduced alpha-aminobutyrate, serine and N-methylglycine concentrations. No variable was associated with SAM/SAH ratio. In addition, gene polymorphisms were not selected as determinants for tHcy, MMA and SAM/SAH ratio. Iron, Cbl and folate deficiencies were found respectively in 30.4%, 22.5% and 2.0% of individuals studied. Conclusions: There was a high frequency of Cbl and iron deficiency in this group of childbearing-age women. Serum folate and Cbl were the determinants of serum tHcy and MMA concentration, respectively. (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
Objectives: To examine the association between methylenetetrahydrofolate reductase (MTHFR) (C677T and A1298C), methionine synthase (MTR) A2756G and methionine synthase reductase (MTRR) A66G gene polymorphisms and total homocysteine (tHcy), methylmalonic acid (MMA) and S-adenosylmethionine/ S-adenosylhomocysteine (SAM/SAH) levels; and to evaluate the potential interactions with folate or cobalamin (Cbl) status. Subjects/ Methods: Two hundred seventy-five healthy women at labor who delivered full-term normal babies. Cbl, folate, tHcy, MMA, SAM and SAH were measured in serum specimens. The genotypes for polymorphisms were determined by PCR-restriction fragment length polymorphism ( RFLP). Results: Serum folate, MTHFR 677T allele and MTR 2756AA genotypes were the predictors of tHcy levels in pregnant women. Serum Cbl and creatinine were the predictors of SAM/SAH ratio and MMA levels, respectively. The gene polymorphisms were not determinants for MMA levels and SAM/SAH ratios. Low levels of serum folate were associated with elevated tHcy in pregnant women, independently of the gene polymorphisms. In pregnant women carrying MTHFR 677T allele, or MTHFR 1298AA or MTRR 66AA genotypes, lower Cbl levels were associated with higher levels of tHcy. Lower SAM/SAH ratio was found in MTHFR 677CC or MTRR A2756AA genotypes carriers when Cbl levels were lower than 142 pmol/l. Conclusions: Serum folate and MTHFR C677T and MTR A2576G gene polymorphisms were the determinants for tHcy levels. The interaction between low levels of serum Cbl and MTHFR (C677T or A1298C) or MTRR A66G gene polymorphisms was associated with increased tHcy.
Resumo:
The main objectives of the present study were (a) to study the effects of the different combinations of Lactobacillus delbrueckii subsp. bulgaricus (Lb), Lactobacillus acidophilus (La), Lactobacillus rhamnosus (Lr), and Bifidobacterium animalis subsp. lactis (BI) in co-culture with Streptococcus thermophilus (St) on the rate of acid development in milk and milk-whey mixture, and (b) the effect of the level of the total solids of the different bases on the acidification profile and viability of potential health-promoting microorganisms. The co-culture of St-Lr showed the lowest values V(max) in all bases; while the co-culture St-Bl had high t(Vmax) in milk and whey bases (12 and 10 g/100 g, respectively). Co-cultures St-La and St-Lb reached V(max) at pH 5.5, while St-Lr and St-Bl at pH 5.91. Fermentation time to reach pH 4.5 was longer when St-Lr co-culture was used, while St-Lb had the lowest value. All the products had slight development of acid during the storage period, and lowest values were observed when the St-Bl co-culture was employed. Lb, BI and St cultures had high counts at pH 4.5 in the three bases. The total solids affected the viability of Lb and La. The technological interest of these combinations is discussed in this article. (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. AM rights reserved.
Resumo:
The interaction of ten natural polyphenolic compounds (chlorogenic acid, apigenin, catechin, epicatechin, flavanone, flavone, quercetin, rutin, vicenin-2 and vitexin) with human serum albumin and mixtures of human serum albumin and alpha(1)-acid glycoprotein under near physiological conditions is studied by capillary electrophoresis-frontal analysis. Furthermore, the binding of these polyphenolic compounds to total plasmatic proteins is evaluated using ultrafiltration and capillary electrophoresis. In spite of the relatively small differences in the chemical structures of the compounds studied, large differences were observed in their binding behaviours to plasmatic proteins. The hydrophobicity, the presence/absence of some functional groups, steric hindrance and spatial arrangement seem to be key factors in the affinity of natural polyphenols towards plasmatic proteins.
Resumo:
In this work total reflection X-ray fluorescence spectrometry has been employed to determine trace element concentrations in different human breast tissues (normal, normal adjacent, benign and malignant). A multivariate discriminant analysis of observed levels was performed in order to build a predictive model and perform tissue-type classifications. A total of 83 breast tissue samples were studied. Results showed the presence of Ca, Ti, Fe, Cu and Zn in all analyzed samples. All trace elements, except Ti, were found in higher concentrations in both malignant and benign tissues, when compared to normal tissues and normal adjacent tissues. In addition, the concentration of Fe was higher in malignant tissues than in benign neoplastic tissues. An opposite behavior was observed for Ca, Cu and Zn. Results have shown that discriminant analysis was able to successfully identify differences between trace element distributions from normal and malignant tissues with an overall accuracy of 80% and 65% for independent and paired breast samples respectively, and of 87% for benign and malignant tissues. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
Solanum lycocarpum A. St. Hil. (Solanaceae) is a hairy shrub or small much-branched tree of the Brazilian Cerrado. S. lycocarpum fruits are commonly used in traditional medicine in powder form or as folk preparations for the treatment of diabetes and obesity, as well as for controlling cholesterol levels. The aim of the present study was to chemically characterize the hydroalcoholic extract (SL) of S. lycocarpum by determination of total flavonoids and total poyphenols and quantification of steroidal alkaloids, as well as to evaluate its mutagenic and/or antimutagenic potential on V79 cells and Swiss mice using chromosomal aberrations and bone marrow micronucleus assays, respectively. Three concentrations of SL (16, 32, and 24 mu g/mL) were used for the evaluation of its mutagenic potential in V79 cells and four doses (0.25, 0.50, 1.0, and 2.0 g/kg body weight) were used for Swiss mice. In the antimutagenicity assays, the different concentrations of SL were combined with the chemotherapeutic agent doxorubicin (DXR). HPLC analysis of SL gave contents of 6.57% +/- 0.41 of solasonine and 4.60% +/- 0.40 of solamargine. Total flavonoids and polyphenols contents in SL were 0.04 and 3.60%, respectively. The results showed that not only SL exerted no mutagenic effect, but it also significantly reduced the frequency of chromosomal aberrations induced by DXR in both V79 cells and micronuclei in Swiss mice at the doses tested.