60 resultados para ß-carotene

em Scielo Saúde Pública - SP


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Butia capitata is a palm tree, widely found in the Brazilian savanna. Their fruits are largely used by local communities to prepare juices, jellies and ice-creams. The main objective of this work was to determine the carotenoids profile of Butia capitata fruits and their provitamin A values. Total carotenoids content ranged from 11.1 to 43.9 μg.g-1; β-carotene was the predominant carotenoid (5.2-22.8 μg.g-1), followed by γ-carotene, phytoene, phytofluene, ζ-carotene, α-cryptoxanthin (or zeinoxanthin) and α-carotene. Provitamin A values varied from 50 to 200 RAE.100g-1. This result suggests that B. capitata pulp may be a good source of β-carotene and provitamin A.

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Objective: to investigate the effect of administration of supraphysiological âcaroteno on biological parameters (ectoscopy and blood pressure), laboratory (malondialdehyde) and histological (liver and carotid arteries) of spontaneously hypertensive rats prone to stroke (SHR-sp).Methods: we used 36 male rats were divided into three groups, each containing 12 rats Wistar, SHR and SHR-sp, subdivided into six control animals and six animals treated with supraphysiological doses of âcaroteno for two periods of ten weeks interspersed with one week interruption. In the experiment were assessed daily physical examination and blood pressure (plethysmography). At sacrifice, blood was collected for measurement of serum malondialdehyde, liver and carotid arteries for histological examination.Results: temporary change in color of the fur, decreased significantly (p<0.0001) blood pressure (20mg supplementation âcaroteno) and serum levels of malondialdehyde (p<0.05) and increased amount of elastic fibers in the carotid wall of SHR and SHR-sp.Conclusion: supplementation of supraphysiological âcaroteno caused no toxic effects, showed positive response in the modulation of blood pressure and lower serum malondialdehyde. No significant morphological changes were found in both groups, except an increase in the number of elastic fibers in the muscle layer carotid suggesting elastosis in SHR and SHR-sp.

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It has been suggested that iron overload may be carcinogenic. In the present study, we evaluated the effect of plasma and prostate carotenoid concentration on oxidative DNA damage in 12-week-old Wistar rats treated with intraperitoneal (ip) ferric nitrilotriacetate (Fe-NTA) (10 mg Fe/kg). Plasma ß-carotene and lycopene concentrations were measured as a function of time after ip injection of carotenoids (10 mg kg-1 day-1 ß-carotene or lycopene) in rats. The highest total plasma concentration was reached 3 and 6 h after ip injection of lycopene or ß-carotene, respectively. After 5 days of carotenoid treatment, lycopene and ß-carotene were present in the 0.10-0.51 nmol/g wet tissue range in the prostate. Using a sensitive method to detected 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) by HPLC/EC, the level of 8-oxodGuo in rat prostate DNA was significantly higher (6.3 ± 0.6 residues/10(6) dGuo) 3 h after Fe-NTA injection compared with control rats (1.7 ± 0.3 residues/10(6) dGuo). Rats supplemented with lycopene or ß-carotene for 5 days prior to Fe-NTA treatment showed a reduction of about 70% in 8-oxodGuo levels to almost control levels. Compared with control rats, the prostate of Fe-NTA-treated animals showed a 78% increase in malondialdehyde accumulation. Lycopene or ß-carotene pre-treatment almost completely prevented lipid damage. Epidemiological studies have suggested a lower risk of prostate cancer in men reporting a higher consumption of tomato products. However, before associating this effect with tomato sauce constituents, more information is required. The results described here may contribute to the understanding of the protective effects of carotenoids against iron-induced oxidative stress.

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This study aims to analyze the influence of dehydration and different preparation methods during home processing related toalpha-carotene, beta-carotene and total carotenoids stability in carrots. Vitamin A values were evaluated after different treatments. Thus, carrots were submitted to steam cooking, water cooking with and without pressure, moist/dry cooking and conventional dehydration. Determination of alpha- and beta-carotenes was made by High-Performance Liquid Chromatography (HPLC) (conditions were developed by us) using spectrophotometric detection visible-UV at 470 nm; a RP-18 column and methanol: acetonitrile: ethyl acetate (80: 10: 10) as mobile phase. Total carotenoids quantification was made by 449 nm spectrophotometer. The retention of the analyzed carotenoids ranged from 60.13 to 85.64%. Water cooking without pressure promoted higher retention levels of alpha- and beta-carotene and vitamin A values, while water cooking with pressure promoted higher retention levels of total carotenoids. Dehydration promoted the highest carotenoid losses. The results showed that, among the routinely utilized methods under domestic condition, cooking without pressure, if performed under controlled time and temperature, is the best method as it reduces losses in the amount of alpha- and beta-carotene, the main carotenoids present in the carrots. Despite the significant carotenoid losses, carrots prepared through domestic methods, remain a rich source of provitamin A.

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Carotenoids are important constituents of food due to their color and because their degradation products generate important volatile compounds in foods. Aroma compounds derived from carotenoids are widely distributed in nature, and they are precursors of many important aromas in foods such as fruits and in flowers as well. They present high aromatic potential and are therefore of great interest to the industries of aromas and fragrances. In this study, more than 300 previously isolated microorganisms with potential for biotransformation of β-carotene present in the culture medium were selected using the plate method; about 80 strains presented capacity to produce aroma compounds and 7 strains were selected by an untrained panel of tasters to generate aroma compounds. The β-ionone was the main compound produced by CS1 (34.0 mg.L-1) and CF9 (42.4 mg.L-1) microorganisms at 72 and 24 hours of fermentation, cultured with and without pre-inoculation, respectively. The β-damascone and pseudoionone were found in low concentrations, 1,1,6-trimethyl-1,2,3,4-tetrahydronaphthalen (TTN) was tentatively identified and other compounds such as apocarotenoids, apparently obtained from the cleavage of the central part of the carotenoid, were detected.

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Iron availability in the diet is very important because iron deficiency affects a large population in the world. The matrix where iron is present has an influence in its availability. The presence of β-carotene is a factor that alters the availability of iron. This research aims to estimate the iron availability in the presence of β-carotene in food mixtures: M1 = egg and pumpkin; M2 = spinach and pumpkin; M3 = spinach and cabbage; M4 = egg and cabbage; M5 = spinach and carrot; M6 = egg and carrot; M7 = bean and carrot; M8 = bean and pumpkin and M9 = bean and cabbage. After cooking, the following figures were determined: proximate composition, oxalic acid, phytic acid, tannin, iron, iron availability in vitro and β-carotene. The data were analyzed by Tukey test (5%). There were no significant statistical differences for oxalic acid. Tannin presented greater results in mixtures with spinach (M2 and M5); phytic acid was greater in bean samples (M7, M8 and M9) and with spinach (M2). Mixtures M5 e M7, with carrot, presented more β-carotene than the others. The best result for iron availability appeared in mixture (M6). A positive correlation was verified between protein and iron dialysis, and between lipids and iron dialysis. Dietetic fiber was an inhibitor to iron availability. Mixtures with egg showed greater iron availability

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The objective of this work was to verify the availability of iron in the presence of vitamin A as components of foods and in combinations with medicines. The iron available was measured in the presence of vitamin A in foods - common bean (B), beef liver (Li) and carrot (C) - and medicines - Fer-In-Sol® (Fer) (Mead Johnson), Arovit® (A) (Roche) and Neutrofer® (N) (Sigma Pharma) - as well as in combinations of both. β-carotene, vitamin A, total iron, heme and non heme iron, percentage of dialyzable iron and amount of dialyzable iron was determined. Vitamin A and β-carotene had a positive effect on the percentage of iron dialysis. Carrot and liver had a better percentage of dialyzable iron than their respective medicine at similar concentrations. Therefore, we can conclude that there has been an influence of vitamin A over the dialysis of iron, being the mixtures containing liver the ones which achieved the highest concentrations of dialyzable iron, and also that, according to the amounts needed to obtain the daily recommended intake of iron, they are good for consumption.

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Abstract Apricot is one of the fruits dried by using different methods, such as sun, convective or microwave drying. The effects of drying methods on the components of this fruit differ depending upon the temperature or time parameters. In this research, the impacts of convective, microwave and microwave–convective drying techniques on color, β-carotene, minerals and antioxidant activity of apricots were investigated. The color values (L*, b*,ΔEab, h° and C*ab) of dried fruit were decreased, while the a* values increased. Compared with a fresh sample, the dried apricots showed a 1.4-3.9-fold proportional increase in β-carotene based on the increment of dry matter. The samples dried at high temperature and microwave levels, at 75 °C+90 watt and 75 °C+160 watt, showed lower antioxidant activity. Of the different drying treatments, the microwave-convective method (50 °C+160 watt) obtained a higher β-carotene content while maintaining antioxidant activity with a short drying time.

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Maytenus guyanensis Klotzch. is an Amazonian medicinal tree species known in Brazil by the common name chichuá and in Peru and Colombia by the name chuchuhuasi. It is used in traditional medicine as stimulant, tonic, and muscle relaxant, for the relief of arthritis, rheumatism, hemorrhoids, swollen kidney, skin eruptions, and skin cancer prevention, among others. Initially, different extraction solvents and methods were applied to dried, ground bark which made possible the preparation of extracts having both significant lethality to brine shrimp larvae (Artemia franciscana Leach) as well as antioxidant activity in vitro based on tests involving reactions with 2,2,-diphenyl-1-picrylhydrazyl (DPPH). Analysis of fractions from serial extractions with solvents of increasing polarity supports the notion that antioxidant activity is associated with compounds of intermediate polarity and cytotoxicity is associated with compounds of low to intermediate polarity. Variation of extraction time and conditions revealed that hot, continuous ethanol extraction provided good yields of bark extract in several hours. Hot extraction also provided ethanol extracts having greater lethality to brine shrimp and antioxidant activity (compared to the flavonoid rutin in semi-quantitative methods based on DPPH) than extracts obtained from maceration at room temperature. Freeze-dried ethanol extracts were prepared by: 1) maceration at room temperature and 2) hot extraction (eight hours) on several hundred gram scales and the latter extract was shown to have partial screening effects on UVB light. In this work, cytotoxic, antioxidant and potential sun-screening activity are shown for the first time in M. guyanensis.

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In the present paper the author reported the results obtained for the chemical caracterization of the pigments of some species of Bryozoa (Polyzoa), living in the bay and the coast near Rio de Janeiro. The pigments (biochromes) of "Bugula neritina", "Schizoporella unicornis", "Steganoporella magnilabris", "Bugula flabellata" and "Trigonospora sp", were extracted and the results showed that carotene was found in all the species, except, "Bugula neritina" and "Bugula flabellata". A new water-soluble pigment was described for "Bugula neritina". Spectrophotometric curves obtained with the Beckman spectrophotometer are reported for the "Bugula" pigment and for the carotenoids. Chromatographic analysis and the treatment with immiscible solvents were performed for all the extracts of the animals considered. A study of the biochromes of other "phyla" will be published in a near future.

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An experiment was conducted to determine the fruit size, mineral composition and quality of trickle-irrigated tomatoes as affected by potassium fertilizer rates. Six potassium (K) rates were applied as KCl, corresponding to 0, 48.4, 118.6, 188.8, 259.0 and 399.4 kg ha-1, with four replicates, following a randomized block design. Quadratic responses to K rates were observed for double extra large (diameter > 60 mm), extra large (56 to 60 mm) and large (52 to 56 mm) fruit yields. Maximum yields of these classes were achieved with K rates of 116, 190 and 233 kg ha-1, respectively. Fruit dry matter, phosphorus, sulfur and magnesium contents were not affected by K rates, but nitrate and K contents showed significant increments as K rates were increased. Vitamin C, total soluble solids, lycopene and beta-carotene contents in the fruits were not affected by K rates. Increments in the K rate lowered the fruit pH and increased total acids content.

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Mauritia vinifera (buriti) is a palm tree that grows wild in different areas of Brazil, particularly in the Amazonian region. The buriti oil is rich in carotenoids, especially in β-carotene. The growing interest in other natural sources of β-carotene has stimulated the industrial use of buriti as a raw material for pulp oil extraction. Most processes are based on the conventional technologies, involving drying and pressing the pulp for oil recovery and further separation of carotenoids in a liquid phase using organics solvents. In the present work, the ethanol-based process was evaluated for simultaneous carotenoids recovering and fractionating from buriti pulp. The raw material and ethanol, 1:4 ratio, were placed in an erlenmeyer flask and maintained at 30rpm for 1 hour in a temperature-controlled bath at 65ºC. The mixture was filtered under vacuum and cooling at 10ºC to allow for the separation of the solvent in two phases. Carotenoids composition, determined by HPLC, has indicated a β-carotene concentration about 12 times greater in the lower phase than in the upper phase. The profile of the carotenoids in the denser phase is quite similar to that of raw buriti oil, and the concentration of total carotenoids is 40% higher than that of the original raw oil, making the ethanol-based process particularly attractive for industrial applications.

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Pereskia aculeata Mill. (Ora-pro-nóbis) is a native cactaceae from tropical America, whose leaves have high protein content. In Brazil it is found in all territorial extension between the states of Bahia and Rio Grande do Sul. Most studies have focused on chemical characterization of the leaves of this specie. The objective was to assess the carotenoids profile and the total polyphenols present in the fruits of P. aculeate. Carotenoids were determined by HPLC-PAD (high performance liquid chromatography - photodiode array detector), total polyphenols were determined by Folin-Ciocalteu and vanillin methods. Trans-β-carotene was the main carotenoid, followed by α-carotene, lutein and other minor carotenoids. It was found 64.9 ± 1.1 mg.100g-1 of gallic acid equivalent, 14.8 ± 0.2 mg.100g-1 of catechin equivalent. Carotenoid identification of P. aculeate fruits are presented here by the first time and indicate that these fruits can be researched as source of bioactive substances, especially antioxidant and provitamin A carotenoids.

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Carotenoid polyenes play a wide role in nature and their photophysical properties make of these pigments a focus of research in photochemistry, photobiology and photomedicine. Some aspects of the singlet and triplet states and, their interaction with molecular and singlet oxygen and free radicals are briefly reviewed in this article.

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This paper reports on the development of a simple and fast procedure for β-carotene extraction from carrots and its quantification by UV/Vis spectroscopy. Carotenoids extracted from carrots may also be used as alternative reagents for TLC (thin layer chromatography) detection of natural compounds with antioxidant properties, replacing the commercial p.a. grade β-carotene. Although this reagent had around 10% b-carotene, it proved to be as efficient for TLC analysis as the commercial p.a. grade β-carotene. This practice is a useful alternative for teaching undergraduate organic chemistry laboratory classes.