336 resultados para CLAE


Relevância:

10.00% 10.00%

Publicador:

Resumo:

A contaminação fúngica acarreta alterações na qualidade nutricional e no valor econômico de produtos alimentícios podendo causar danos patológicos em plantas, animais e humanos. A identificação da atividade antioxidante, antifúngica e antimicotoxinas, em extratos de microalgas com propriedade de inibir a multiplicação de fungos e subseqüente produção de micotoxinas abre a perspectiva de empregar substâncias mais eficientes e com maior ação específica contra estes microorganismos. Entre os compostos com propriedades inibidoras de radicais livres, de crescimento fúngico e produção de micotoxinas, destacam-se os compostos fenólicos, que podem inibir a atividade metabólica microbiana, dificultando a atividade de enzimas. Neste estudo foram avaliados o poder de inibição de multiplicação fúngica de Rhizopus oryzae e Aspergillus flavus pelos extratos fenólicos de Chlorella sp. e Spirulina platensis, bem como sua atividade antioxidante, e a atividade antimicotoxinas da última microalga contra Aspergillus flavus. O conteúdo de fenóis totais foi em média 1000 µgfenóis/g Spirulina platensis e 600 µgfenóis/g Chlorella sp., sendo que o acido gálico e o cafeíco foram identificados como compostos majoritários na Spirulina platensis. As determinações de glicosamina (parede celular) e ergosterol (membrana celular) mostraram-se bons indicativos do desenvolvimento microbiano permitindo uma boa estimativa da inibição dele. O extrato fenólico de Spirulina platensis apresentou capacidade de inibir cerca de 50% a formação da parede e da membrana celular para ambos os fungos estudados e de 100% a produção de aflatoxina B1 até o 10º dia de cultivo do Aspergillus flavus. Além disso, o extrato metanólico de Spirulina platensis inativou 53,5% o DPPH reativo, limitou o escurecimento enzimático ocasionado pela peroxidase em 55% e inibiu a peroxidação lipídica em 46% após 14 dias de armazenamento sob luz. Estes resultados mostram que a ação antifúngica, antimicotoxinas e antioxidante está naturalmente presente em alguns tecidos microbianos e que encontrar a forma de extraí-los e aplicá-los como conservantes alimentícios é muito promissor para substituição aos antifúngicos e outros conservantes químicos.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The consumer interest in healthy foods with high amounts of antioxidants is one of the important factors for reducing the risk of disease and it has encouraged researchers and industry to develop innovative and functional products and ingredients. To that end, the objective of this research was to study the bioactive compounds present in the acai pulp, blueberry and goji berry samples, as well as the phenolic compounds form of extraction using the response surface methodology (RSM), antioxidant and antimicrobial activity of it, identification and quantification of compounds by high-performance liquid chromatography (HPLC) and, at the end, the development of petit suisse cheeses added with freeze-dried extracts of the samples. A 2³ factorial design was used to analyze the solvent effect (ethanol and water), time (30 and 60 min) and temperature (30 °C and 60 °C) on the extraction and determination of total phenolic compounds (TPC) and antioxidant activity (AA). The variables time and temperature had a positive effect on the antioxidant activity (AA) in their highest levels with 60 min and 60 °C respectively. The ethanol solvent 80 % is more efficient in TPC extraction with AA in all arrays. The identification of phenolic compounds performed by HPLC revealed the presence of catechin, epicatechin, rutin, myricetin, chlorogenic acid, coumaric acid and ferulic acid. Regarding the AA the acai pulp showed higher activity in vitro when extracted by 60 °C for 60 min, but none of the three extracts analyzed under these conditions showed antibacterial activity against Staphylococcus aureus and Salmonella bongori in the concentrations tested (95.00 to 2.34 mg/mL. For petit suisse cheeses added with phenolic extract of the samples, the sample containing goji berry achieved greater sensory acceptance among judges (75.67%), second only to the commercial sample used for comparison with 91.56 % of acceptance. In relation to the storage time, the oxidation was evaluated by the level of thiobarbituric acid reactive substances and color analysis. Both analysis were satisfactory, making the extracts addition an alternative to preserve the product properties and give it a high content of bioactive and nutritive compounds.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The routine analysis for quantization of organic acids and sugars are generally slow methods that involve the use and preparation of several reagents, require trained professional, the availability of special equipment and is expensive. In this context, it has been increasing investment in research whose purpose is the development of substitutive methods to reference, which are faster, cheap and simple, and infrared spectroscopy have been highlighted in this regard. The present study developed multivariate calibration models for the simultaneous and quantitative determination of ascorbic acid, citric, malic and tartaric and sugars sucrose, glucose and fructose, and soluble solids in juices and fruit nectars and classification models for ACP. We used methods of spectroscopy in the near infrared (Near Infrared, NIR) in association with the method regression of partial least squares (PLS). Were used 42 samples between juices and fruit nectars commercially available in local shops. For the construction of the models were performed with reference analysis using high-performance liquid chromatography (HPLC) and refractometry for the analysis of soluble solids. Subsequently, the acquisition of the spectra was done in triplicate, in the spectral range 12500 to 4000 cm-1. The best models were applied to the quantification of analytes in study on natural juices and juice samples produced in the Paraná Southwest Region. The juices used in the application of the models also underwent physical and chemical analysis. Validation of chromatographic methodology has shown satisfactory results, since the external calibration curve obtained R-square value (R2) above 0.98 and coefficient of variation (%CV) for intermediate precision and repeatability below 8.83%. Through the Principal Component Analysis (PCA) was possible to separate samples of juices into two major groups, grape and apple and tangerine and orange, while for nectars groups separated guava and grape, and pineapple and apple. Different validation methods, and pre-processes that were used separately and in combination, were obtained with multivariate calibration models with average forecast square error (RMSEP) and cross validation (RMSECV) errors below 1.33 and 1.53 g.100 mL-1, respectively and R2 above 0.771, except for malic acid. The physicochemical analysis enabled the characterization of drinks, including the pH working range (variation of 2.83 to 5.79) and acidity within the parameters Regulation for each flavor. Regression models have demonstrated the possibility of determining both ascorbic acids, citric, malic and tartaric with successfully, besides sucrose, glucose and fructose by means of only a spectrum, suggesting that the models are economically viable for quality control and product standardization in the fruit juice and nectars processing industry.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The vitamin A is essential to animals because of its participation in a great number of biological functions. The investigation of this vitamin s concentrations is important to serve as reference to normality parameters. This study had as aim to analyse the serics and hepatics concentrations of vitamin A in two groups of bovines and to compare the hepatics concentrations to the present requeriments of vitamin A for pregnant women. It was also appraised the consume habit of bovine liver by pregnant women through of the alimentary frequency quest. Two groups of bovine were studied and the first was formad by Nelore bovine breed and the second by bovine without defined breed (WDB). It was analysed 120 samples: 60 of liver and 60 of serum. The method used to dose retinol was High Performance Liquid Cromatography (HPLC). The average (+ sd) of retinol concentrations in Nelore breed bovine and WDB liver were 16947,8 + 6866,9 and 5213,1 + 2517,2 µg of retinol/100g and at serum 39,6 + 17,9 e 28,6 + 9,4 µg of retinol/dL, respectively. No statistically significant correlation was found between hepatic and the serum retinol. The bovines in this study had adequate vitamin A levels. Independently of animal breed, the daily ingestion of bovine liver is not advised for pregnant women who show adequate support of vitamin A. The consume of bovine liver by pregnant women consulted on school maternity hospital Januário Cicco, UFRN, Natal RN, was considered high

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This work studies the involved enzymatic way in the metabolism of glycosaminoglycans sulfateds in the mollusc Pomacea sp. Had been identified endoglycosidases and exoglycosidases in the enzymatic extract of the mollusc Pomacea sp by means of hydrolysis activity in condroitim sulphate of whale cartilage and of the p-Nitrofenil-β-glucuronide, respectively. The enzymatic extracts qere obtained of Pomacea sp. being used of 0.1 sodium acetate buffer, pH 5.0 and later centrifugated the 8,000 x g and the presents proteins in the sobrenadante were submitted to the fractionament with two crescents ammonium sulphate concentrations, the visualized activity biggest in the F2 fraction (50-80%). The β-glucuronidase (F3) was isolated in gel chromatography filtration Biogel 1.5m, the purification degree was ratified in Chromatography Liquid of high efficiency (HPLC). The enzyme was purificated 6.362,5 times with 35,6% yield. The β -glucuronidase isolated in this work showed a molecular mass of 100 kDa, determined for eletroforese in poliacrilamida gel . The determination of the ideal kinetic parameters for the catalysis of the p-nitrofenil- β -glucuronide for β-glucuronidase, showed excellent activity in pH 5,0 and temperature 65ºC for 6 hours and apparent Km of 72 x 10-2 mM. It is necessary for the total degradation of 3mM of p-N-β-glucoronide, the amount of 1,2μg of ss-glucuronidase. The BaCl2 increased the activity of ss-glucuronidase, and the activity was inhibited completely by the composites SDS and NaH2PO4

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The intake of adequate quantities of food, including those rich in vitamins, is necessary for a healthy life. The lack of vitamin A has been characterized as a public health problem in developing countries, however, a high intake of vitamin A can result in toxic and teratogenics effects. High concentrations of vitamin A have been observed in the livers of animals. The objective of this study was to assess the levels of retinol in chicken livers and verify the effect of frozen storage on these levels. 64 livers from two chicken strains, Cobb and Ross, were used, came from four different farms. We examined 32 livers from each strain, 8 samples from each farm. Liver sample were homogenized individually, then 4 aliquots were taken from each sample. One of aliquots was analyzed immediately after slaughter (T0), the others were analyzed after 30, 60 and 90 days of storage at -18oC (T30, T60 and T90, respectively). Retinol dosage in the liver was determined by High Performance Liquid Chromatography (HPLC). The levels of retinol varied significantly according to the strain. The mean retinol value in the fresh samples was 6678.0 ± 1337.7 and 8324.1 ± 1158.5 µg/100g in the Cobb and Ross strain, respectively. Values of 4258 ± 918.7 ± 1391.7 and 4650.5 ± 1391.7 μg/100g were found after 90 days of storage for Cobb and Ross strain, respectively. The liver freezing caused a significant reduction in their levels of retinol, causing a loss of up to 44% with respect to fresh livers. The reduction in retinol levels occurred from 30 days of storage. Even with the losses from the frozen, the ingestion of a typical portion of 100 g of liver, regardless the chicken strain analyzed, surpass all recommendations of consumption and the maximum tolerable intake of vitamin A (3000 μg/day) for adults

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Com o aumento da produção do fulereno C60 e sua aplicação comercial é previsível que este composto acabe sendo liberado no ambiente, tornando-se um contaminante. Em razão das suas características físico-químicas e sua capacidade de formar agregados (n-C60) quando em contato com a água, o C60 pode se tornar um carreador de outros contaminantes (como metais e compostos orgânicos), facilitando a sua entrada nos organismos. Neste sentido, a sua toxicidade (tanto de forma isolada como em associação com outros contaminantes) vem sendo avaliada. Sendo assim, a fim de viabilizar os estudos com C60, uma metodologia para preparo de suspensões aquosas foi validada, sendo quantificada por CLAE/UV-Vis. As suspensões foram preparadas sem a adição de solvente de duas formas distintas, com aquecimento (50ºC) e à temperatura ambiente (≈20 ºC), onde se mantiveram sob agitação constante e exposição à luz artificial por até 2 meses. A cada 15 dias a suspensão foi quantificada. Além disso, três métodos distintos de extração e pré-concentração (extração líquido-líquido (ELL), extração em fase sólida (EFS) e micro-extração dispersiva líquido-líquido (MEDLL)) foram validados e comparados quanto a sua eficiência. Coeficientes de correlação ≥ 0,99 foram obtidos para as curvas de calibração. Os LDM e LQM foram de 0,08 e 0,3 ng mL-1 para EFS e ELL, considerando o fator de concentração de 500 vezes, e de 0,8 e 3,0 ng mL-1 para a MEDLL, considerando o fator de concentração de 50 vezes, respectivamente. A precisão (intermediária e repetitividade) variou entre 0,46 e 4,03 (%RSDpi) e entre 0,69 e 3,59 (%RSDr), enquanto que a exatidão ficou entre 72,3 e 85,6% para ELL, 86,1 e 115,5% para a EFS e 87,9 e 111,4% para MEDLL. Com base nestes parâmetros relativos a análise de suspensões aquosas de C60, a EFS foi considerada o método mais eficiente. O aquecimento se mostrou relevante no tamanho dos agregados, que foram significativamente maiores na suspensão sem aquecimento, porém o tempo de preparo da suspensão não influenciou na concentração final da suspensão. Portanto, recomenda-se o preparo das suspensões aquosas de C60 sem aquecimento por um período de agitação de 30-45 dias.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Vitamin A deficiency (VAD) is a serious public health problem in developing countries, and as a therapeutic and prophylactic measure retinil palmitate is being supplemented. Nevertheless its efficacy has been questioned. The objective of the study was to evaluate the supplementation of two retinil palmitate megadosis on the serum retinol levels of post partum healthy mothers from Dr. José Pedro Bezerra (Hospital Santa Catarina) hospital, Natal - RN. The enrolled women (n=199) were randomly distributed into three studied groups and supplemented with retinil palmitate immediately after delivery with a single 200,000 IU dose (group S1), two 200,000 IU dose (group S2) with 24h difference between the doses, or no supplementation (group C). Among women selected, 143 remained until the end of the study. The influence of vitamin A dietary intake was evaluated during pregnancy and after 30 days of delivery. The average intake of the population was reasonable, but a high prevalence of inadequate intake was found. Retinol in colostrums and mature milk was determined by high performance liquid chromatography (HPLC). The retinol average in colostrums and mature milk in the supplemented and control groups were adequate according to the reference values. In colostrums, women from groups C, S1 and S2 presented retinol averages by milk volume of 94.8 ± 40.2 µg/dL, 92.2 ± 50.0 µg/dL and 91.8 ± 53.7 µg/dL, respectively. No difference was found between these averages (p=0.965), this was also seen when the values where expressed as µg/g of fat (p=0.905). After 30 days of delivery, retinol per milk volume differed between the control group (36.6 ± 17.5 µg/dL) and groups supplemented with 200,000 IU (51.0 ± 28.8 µg/dL) or 400,000 IU (55.2 ± 31.6 µg/dL) of retinil palmitate (p<0,05). Nevertheless, when S1 and S2 groups where compared, no significant difference was found (p=0.97). Considering retinol/g of fat, the means were 12.7 ± 6.7 µg/g, 15.6 ± 8.3 µg/g and 17.2 ± 8.9 µg/g for groups C, S1 and S2, respectively, with significant difference between groups S2 and C (p=0,01). Subclinical VAD prevalence showed a serious public health problem in the study population (32% in colostrums and 31.5% in mature milk). When analyzing the groups separately, the group which received two doses (200,000 IU + 200,000 IU) presented the lowest VAD prevalence (20.7%). Retinil palmitate supplementations of 200,000 IU and 400,000 IU (divided in two doses) in the immediate post partum showed no significant difference. Nevertheless, the 400,000 IU (divided in two doses) supplementation showed a reduction in VAD

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The corn cob is an agricultural by-product still little used, this in part due to the low knowledge of the biotechnological potential of their molecules. Xylan from corn cobs (XSM) is a polysaccharide present in greater quantity in the structure of plant and its biotechnology potential is little known. This study aimed to the extraction, chemical characterization and evaluation of biological activities of xylan from corn cobs. To this end, corncobs were cleaned, cut, dried and crushed, resulting in flour. This was subjected to a methodology that combines the use of alkaline conditions with waves of ultrasound. After methanol precipitation, centrifugation and drying was obtained a yield of 40% (g/g flour). Chemical analysis indicated a high percentage of polysaccharides in the sample (60%) and low contamination by protein (0.4%) and phenolic compounds (> 0.01%). Analysis of monosaccharide composition indicated the presence of xylose:glucose:arabinose:galactose:mannose:glucuronic acid in a molar ratio 50:20:15:10:2.5:2.5. The presence of xylan in the sample was confirmed by nuclear magnetic resonance (¹H and ¹³C) and infrared spectroscopy (IR). Tests were conducted to evaluate the antioxidant potential of XSM. This showed a total antioxidant capacity of 48.45 EAA/g sample. However, did not show scavenging activity of superoxide and hydroxyl radical and also reducing power. But, showing a high capacity chelating iron ions with 70% with about 2 mg/mL. The ability to XSM to influence cell proliferation in culture was also evaluated. This polymer did not influence the proliferation of normal fibroblast cells (3T3), however, decreased the rate of proliferation of tumor cells (HeLa) in a dose-dependent, reaching an inhibition of about 50% with a concentration around 2 mg/mL. Analyzing proteins related to cell death, by immunoblotting, XSM increases the amount of Bax, Bcl-2 decrease, increase cytochrome c and AIF, and reduce pro-caspase-3, indicating the induction of cell death induced apoptosis dependent and independent of caspase. XSM did not show anticoagulant activity in the PT test. However, the test of activated partial thromboplastin time (aPTT), XSM increased clotting time at about 5 times with 600 μg of sample compared with the negative control. The presence of sulfate on the XSM was discarded by agarose gel electrophoresis and IR. After carboxyl-reduction of XSM the anticoagulant activity decreased dramatically. The data of this study demonstrate that XSM has potential as antioxidant, antiproliferative and anticoagulant compound. Future studies to characterize these activities of XSM will help to increase knowledge about this molecule extracted from corn and allow their use in functional foods, pharmaceuticals and chemical industries.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A ocratoxina A (OTA), micotoxina encontrada em diferentes níveis e em diversas matrizes, apresenta efeitos carcinogênicos, nefrotóxicos e teratogênicos. O desenvolvimento de métodos capazes de diminuir esta contaminação a níveis permitidos pela legislação é incentivado e os processos biológicos utilizados envolvem o uso de enzimas e/ou microrganismos para degradação da OTA e são preferenciais pela especificidade, bem como pelas condições brandas para a detoxificação. O objetivo do trabalho foi estudar a ação de carboxipeptidase A nos níveis e na toxicidade de OTA, visando aplicar a técnica para detoxificar farinhas de trigo. Primeiramente foi estimado o risco de exposição à ocratoxina A pelo consumo de farinhas de trigo. Para isso foram estabelecidas condições de determinação de OTA em farinhas de trigo, empregando técnicas de estatística multivariada para definir os principais interferentes na extração de OTA pelo método de QuEChERS e detecção em CLAE-FL. O método validado permitiu a avaliação da ocorrência natural em 20 amostras de farinha de trigo, estando estas contaminadas na faixa de 0,22 a 0,85 µg.kg-1 , apresentando um valor de ingestão diária de 0,08 ngOTA.dia-1 .kgmassacorpórea -1 e uma disponibilidade de 94,4%. Em seguida foi realizada a padronização da extração de carboxipeptidase A em biomassa de Rhizopus oryzae que consistiu em agitação ultrassônica durante 30 minutos numa potencia fixa de 150 W e 40 kHz e a triagem de agentes biológicos para degradação de OTA. Para o estudo da degradação in vitro de OTA, método de extração e detecção de OTA e OTα em CLAEFL foi validado e o processo de degradação foi realizado com Rhizopus oryzae e Trichoderma reesei, obtendo-se uma redução máxima de 63,5% e 57,7%, respectivamente. A degradação apresentou uma correlação alta (R>0,9) e significativa (p<0,05) com a produção de Otα, indicando que ocorreu a produção de enzimas capazes de hidrolisar a micotoxina, por exemplo, a carboxipeptidase A. O estudo da toxicidade de OTA e seu metabólito OTα foi realizado em neutrófilos humanos, onde foi observado a ausência de efeito tóxico de OTα. Também foi determinado o mecanismo de toxicidade de OTA pelo aumento de Ca2+ intracelular pela liberação a partir das reservas internas. Esta liberação, subsequentemente, provoca uma cascata de eventos, nomeadamente: a produção de espécies reativas, depleção de ATP, perda de ΔΨm, levando à morte por necrose. Para reduzir o risco de exposição à micotoxina pela ingestão de matéria prima contaminada, carboxipeptidase A extraída de diferentes fontes foi aplicada na hidrólise de OTA em farinha de trigo para posterior determinação do conteúdo residual de OTA e OTα, empregando método validado. O estudo mostrou uma redução de OTA entre 16,8 e 78,5% e produção de OTα entre 2 a 8,2 ng.g-1 . As carboxipeptidases mais promissoras para degradação foram as provenientes de Rhizopus e Trichoderma e a carboxipeptidase comercial. Ficou demonstrado que se pode recomendar a aplicação de enzimas proteolíticas, tipo carboxipeptidase, para reduzir o risco de exposição à micotoxina quando utilizada matéria prima contaminada, por exemplo, farinha de trigo para diferentes processos. A transformação de OTA para OTα e seus efeitos na redução da toxicidade da micotoxina corroboram com esta afirmação.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Vitamins A and E are essential nutrients in many biological processes, so that their adequate supply to the neonate is crucial. However, the bioavailability of vitamins may be limited by factors such as maternal nutritional status and the interaction between nutrients. This study aimed to investigate the effect of biochemical nutritional status of retinol and alpha-tocopherol levels in serum and colostrum. The study included 103 healthy puerperal women treated at the reference state maternity hospital (Natal-RN). Colostrum and serum samples were collected fasting in the immediate postpartum period and the analysis of retinol and alpha-tocopherol were determined by high-performance liquid chromatography. Specific cutoff points were adopted to characterize the biochemical status of vitamins A and E. For the total group of lactanting women the average concentration of retinol in serum (1.49 ± 0.4 μmol/L-1) and colostrum (2.18 ± 0.8 μmol/L-1), as well as alpha-tocopherol in serum (26.4 ± 8.0 μmol/L-1) and colostrum (26.1 ± 12.8 μmol/L-1), indicated adequate biochemical state. However, when evaluating the individual, was found a high prevalence of deficient serum (15%) and colostrum retinol (50%), and also alphatocopherol in serum (16%) and colostrum (61%). In women with serum retinol ≥ 1.05 μmol/L-1, found an inverse correlation between serum retinol and alpha-tocopherol in colostrum (p = 0.008, r = -0.28). This association was not observed in women with serum retinol <1.05 μmol/L-1. This situation demonstrates for the first time in humans that high physiological levels of serum retinol, without supplementation, can negatively influence the transfer of alpha-tocopherol in breast milk. Although the diagnosis of satisfactory nutritional status lactanting women showed high risk of subclinical deficiency of vitamins A and E from measurements made in the colostrum

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective: To evaluate the differences between goblet cell density (GCD) and symptomatology after one month of orthokeratology lens wear. Methods: A pilot, short-term study was conducted. Twenty-two subjects (29.7. ±. 7.0 years old) participated voluntarily in the study. Subjects were divided into two groups: habitual silicone hydrogel contact lens wearers (SiHCLW) and new contact lens wearers (NCLW). Schirmer test, tear break up time (TBUT), Ocular Surface Disease Index (OSDI) questionnaire and conjunctival impression cytology. GCD, mucin cloud height (MCH) and cell layer thickness (CLT) were measured. All measurements were performed before orthokeratology fitting and one month after fitting to assess the evolution of the changes throughout this time. Results: No differences in tear volume and TBUT between groups were found (p>0.05). However, the OSDI score was statistically better after one month of orthokeratology lens wear than the baseline for the SiHCLW group (p=0.03). Regarding the goblet cell analysis, no differences were found in CLT and MCH from the baseline visit to the one month visit for the SiHCLW compared with NCLW groups (p>0.05). At baseline, the GCD in the SiHCLW group were statistically lower than NCLW group (p<0.001). There was a significant increase in GCD after orthokeratology fitting from 121±140cell/mm2 to 254±130cell/mm2 (p<0.001) in the SiHCLW group. Conclusion: Orthokeratology improves the dry eye subject symptoms and GCD after one month of wearing in SiHCLW. These results suggest that orthokeratology could be considered a good alternative for silicone hydrogel contact lens discomfort and dryness. © 2016 British Contact Lens Association.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Vitamin E consists of eight chemically homologous forms, designated alpha, beta, gamma and delta tocopherols and tocotrienols. Biologically, the alpha-tocopherol (α-TOH) is the most important. Commercially, are found two types of α-TOH a natural (RRR-alpha-tocopherol) and another synthetic (all-rac-alpha-tocopherol). Both forms are absorbed in the intestine, the liver is a preference in favor of forms 2R, due to transfer protein α-TOH. It has higher affinity to these stereoisomers. Newborns are considered high risk for vitamin E deficiency, mainly premature, these have breast milk as a food source for maintenance of serum α-TOH. Clinical signs such as thrombocytosis, hemolytic anemia, retrolental fibroplasia, intraventricular hemorrhage, bronchopulmonary dysplasia and spinocerebellar degeneration can be found in case of a low intake of α-TOH. Thus, maternal supplementation on postpartum with α-TOH can be an efficient way to increase levels of vitamin E in breast milk and thus the consequently increase the supply of micronutrient for the newborn. However, most studies with vitamin E supplementation have been conducted in animals and little is known about the effect of maternal supplementation in humans, as well as on its efficiency to increase levels of α-TOH in human milk, depending on the shape natural or synthetic. The study included 109 women, divided into three groups: control without supplementation (GC) (n=36), supplemented with natural capsule (GNAT) (n=40) and the synthetic capsule (GSINT) (n=33). Blood samples were collected for determination of maternal nutritional status, and colostrums at initial contact and after 24 hours post-supplementation. Analyses were performed by High Performance Liquid Chromatography. Values of α-TOH in serum below 499.6mg/dL were considered deficient. We used the Kruskal-Wallis test and Tukey test to confirm the increase of alpha-tocopherol in milk and efficiency of administered capsules. Daily consumption of α-TOH was based on daily intake of 500 mL of colostrum by the newborn and compared with the nutritional requirement for children from 0 to 6 months of age, 4 mg / day. The mothers had mean concentration of serum α-TOH in 1016 ± 52, 1236 ± 51 and 1083 ± 61 mg / dL, in CG, GNAT and GSINT respectively. There were no women with deficiiency. The GC did not change the concentrations of α-TOH in colostrum. While women supplemented with natural and synthetic forms increased concentrations of α-TOH colostrum in 57.6% and 39%, respectively. By comparing supplemented groups, it was observed a significant difference (p=0.04), the natural capsule more efficient than the synthetic, approximately 49.6%. Individually, 21.1% of the women provided below 4mg/day of α-TOH, after supplementation for this index declined4.1%. Thus, maternal supplementation postpartum raised the levels of alpha-tocopherol in colostrum, and increased efficiency was observed with the natural form

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Vitamin A deficiency is a serious public health problem in developing countries, and it causes death and blindness among children in the developing countries. The fortification of food could be an important source of vitamins to control deficiency. 60 Coturnix coturnix japonica quails were used in a randomized design with duration of seven weeks. The birds were assigned into five treatments with four repetitions. The objective was to evaluate the influence of the supplementation with different levels of retinyl palmitate (2,000 IU, 4,000 IU, 8,000IU and 16,000 IU) in quails under the levels of retinyl in egg yolks. The method used to dose retinyl in yolks of quail eggs was High Performance Liquid Chromatography and the enzymatic method to quantify the cholesterol concentration. The weight and production of eggs was significantly modified by the supplementation with retinyl in the birds. The results showed a gradual increase in the incorporation of retinyl in the egg yolk as a response to the supplementation, reaching values 384% higher than the control values. By the end of the supplementations a significant reduction in the concentrations of retinyl in the eggs yolk was observed. The most lasting supplementations were with 8,000 IU and 16,000 IU which lasted for three weeks. The cholesterol content in eggs was not significantly modified. The consumption of one egg enriched with 16000UI of retinol palmitate in the present study, by day, would probably reach 10 and 7,3% of the daily recommendations of this micronutrient for children of 1 to 3 years of age, and for 4 to 8 years, respectively. The nutritional value of eggs, related to the vitamin A, can be improved by supplementation of quails

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The tendency towards reduction of serum retinol levels, an existing placental barrier and the increase of retinol demand, are factors that place puerperal and lactating women at risk for Vitamin A deficiency. This micronutrient is an essential component of vital processes such as differentiation, cellular proliferation, and apoptosis. The objective of this study is to evaluate the effect of palmitate retinol supplementation (100.000UI) upon the milk retinollevels in puerperal women at the Januário Cicco University Maternity Hospital. This intervention has been adopted by the Ministry of Health since 2002. The longitudinal experiment was conducted with 106 puerperal women (68 comprised the supplemented group and 38 the control group). The High Performance Liquid Chromatography (HPLC) method was used to dose the retinol of the milk and serum samples, and the creamtocrit method to determine the milk fat levels. The retinol means for the colostrums were 99.0 ± 64.4 ug/dL and 160.1 ± 94,4 ug/dl 6 hours afier supplementation; 68.9 ± 33.5 ug/dL for the transitional milk, and 30.6 ± 15.2 ug/dL for the mature milk of the supplemented group. Ali the difterences between means were statistically significant. The difterence between retinol means in the control group were also significant, with these being greater in the colostrum, 88.6 ± 62.1 ug/dL with 61.9 ± 30.1 ug/dl in the transition milk and 32.9 ±32.9 ± 17.6 ug/dL in the mature milk. No significant difference was observed in the retinol means of the three types ot milk in the supplemented group when compared to their respective means in the control group. The prevalence in serum (35.1 % and 81.1 % for the cutting point 20 ug/dL, respectively) and in milk (51.4%) revealed vitamin A deficiency as a public health problem. COlostrum, transition, and mature milk tats varied similarly in the supplemented group (1,92 ± 0,96; 3,25 ± 1,27 and 3,31 ± 1,36 grams) and in the control group (1,87 ± 1,14; 3,25 ± 1,31 and 3,36 ± 1,67 grams), with an observed difference between the colostrum/transition milk and the colostrum/mature milk fats. No difference was observed between the groups. The study showed that the 200.000UI supplementation was not sufficient to increase the milk retinol to the desired levels nor to meet the demands of the mothers with deprived hepatic reserves. It is suggested that another similar dose be offered within 30 days or less, and within 2 months post-partum, while continual/y monitoring for possible pregnancy