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1.
Molecules ; 26(13)2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34209163

RESUMO

The feasibility of obtaining resistant starch type III (RS3) from malanga flour (Xanthosoma sagittifolium), as an unconventional source of starch, was evaluated using the hydrothermal treatment of autoclaving. The physicochemical characterization of RS3 made from malanga flour was carried out through the evaluation of the chemical composition, color attributes, and thermal properties. In addition, the contents of the total starch, available starch, resistant starch, and retrograded resistant starch were determined by in vitro enzymatic tests. A commercial corn starch sample was used to produce RS3 and utilized to compare all of the analyses. The results showed that native malanga flour behaved differently in most of the evaluations performed, compared to the commercial corn starch. These results could be explained by the presence of minor components that could interfere with the physicochemical and functional properties of the flour; however, the RS3 samples obtained from malanga flour and corn starch were similar in their thermal and morphological features, which may be related to their similarities in the content and molecular weight of amylose, in both of the samples. Furthermore, the yields for obtaining the autoclaved powders from corn starch and malanga flour were similar (≈89%), which showed that the malanga flour is an attractive raw material for obtaining RS3 with adequate yields, to be considered in the subsequent research.


Assuntos
Farinha , Amido Resistente , Xanthosoma/química , Zea mays/química
2.
Food Chem ; 344: 128666, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33248837

RESUMO

The corms of cocoyams, specifically Colocasia esculenta (L.) Schott and Xanthosoma sagittifolium (L.) Schott are usually consumed as pastes. Nevertheless, the secondary corms, also named cormels, are not fully exploited. In this study, the chemical composition and functional properties of cormels from different botanical sources were evaluated, and the digestibility of the resulting pastes investigated. Colocasia spp. flour contained significantly higher protein (10.32% vs 9.65%), ash (5.65% vs 5.05%) and oxalates (0.32% vs 0.22%) content, and exhibited lower Amylab gel strength (773 g vs 1040 g) than Xanthosoma spp. flour. In the resulting pastes, micrographs revealed that starch gelatinization depended on cocoyam variety. Indeed, the very tight and closed microstructure of pastes containing Colocasia spp. flour led them to better stability during storage with lower syneresis. Lower protein digestibility was obtained in Colocasia spp. gels (67.56% vs 70.91%), but they showed faster (higher k) in vitro starch hydrolysis (0.0140 vs 0.0050) with lower estimated glycemic index (61.29 vs 65.84) than Xanthosoma spp. gels. The present findings offer ways to develop cocoyam based foods by using cormels, enhancing the applicability of cocoyams.


Assuntos
Fenômenos Químicos , Colocasia/química , Farinha/análise , Alimentos , Valor Nutritivo , Xanthosoma/química , Índice Glicêmico , Pomadas , Amido/química
3.
Curr Protoc Protein Sci ; 101(1): e113, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32882112

RESUMO

Glycosylated proteins, namely glycoproteins and proteoglycans (collectively called glycoconjugates), are indispensable in a variety of biological processes. The functions of many glycoconjugates are regulated by their interactions with another group of proteins known as lectins. In order to understand the biological functions of lectins and their glycosylated binding partners, one must obtain these proteins in pure form. The conventional protein purification methods often require long times, elaborate infrastructure, costly reagents, and large sample volumes. To minimize some of these problems, we recently developed and validated a new method termed capture and release (CaRe). This method is time-saving, precise, inexpensive, and it needs a relatively small sample volume. In this approach, targets (lectins and glycoproteins) are captured in solution by multivalent ligands called target capturing agents (TCAs). The captured targets are then released and separated from their TCAs to obtain purified targets. Application of the CaRe method could play an important role in discovering new lectins and glycoconjugates. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Preparation of crude extracts containing the target proteins from soybean flour Alternate Protocol 1: Preparation of crude extracts from Jack bean meal Alternate Protocol 2: Preparation of crude extracts from the corms of Colocasia esculenta, Xanthosoma sagittifolium, and from the bulbs of Allium sativum Alternate Protocol 3: Preparation of Escherichia coli cell lysates containing human galectin-3 Alternate Protocol 4: Preparation of crude extracts from chicken egg whites (source of ovalbumin) Basic Protocol 2: Preparation of 2% (v/v) red blood cell suspension Basic Protocol 3: Detection of lectin activity of the crude extracts Basic Protocol 4: Identification of multivalent inhibitors as target capturing agents by hemagglutination inhibition assays Basic Protocol 5: Testing the capturing abilities of target capturing agents by precipitation/turbidity assays Basic Protocol 6: Capturing of targets (lectins and glycoproteins) in the crude extracts by target capturing agents and separation of the target-TCA complex from other components of the crude extracts Basic Protocol 7: Releasing the captured targets (lectins and glycoproteins) by dissolving the complex Basic Protocol 8: Separation of the targets (lectins and glycoproteins) from their respective target capturing agents Basic Protocol 9: Verification of the purity of the isolated targets (lectins or glycoproteins).


Assuntos
Galectina 3/isolamento & purificação , Glicoconjugados/isolamento & purificação , Testes de Inibição da Hemaglutinação/normas , Testes de Hemaglutinação/normas , Proteoglicanas/isolamento & purificação , Animais , Proteínas Sanguíneas , Bovinos , Eletroforese em Gel de Poliacrilamida/métodos , Eritrócitos/química , Eritrócitos/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Filtração/métodos , Farinha/análise , Galectina 3/química , Galectina 3/genética , Galectina 3/metabolismo , Galectinas , Glicoconjugados/química , Glicosilação , Humanos , Ligação Proteica , Proteoglicanas/química , Coelhos , Glycine max/química , Tireoglobulina/farmacologia , Xanthosoma/química
4.
Polim Med ; 50(1): 21-31, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32975053

RESUMO

BACKGROUND: Ibuprofen is used both for acute and chronic disorders, such as ankylosing spondylitis, osteoarthritis and rheumatoid arthritis; however, ibuprofen causes gastrointestinal disturbances. Therefore, it would be desirable to design it as a sustained-release preparation. OBJECTIVES: To design ibuprofen microbeads using polymers obtained from Xanthosoma sagittifolium starch and Dillenia indica mucilage to provide sustained-release delivery of ibuprofen. MATERIAL AND METHODS: The polymers were extracted using standard methods and characterized by their material, physicochemical, elemental, and rheological profiles. Microbeads loaded with ibuprofen were prepared using the ionotropic gelation method utilizing blends of the polymers and sodium alginate. The microbeads were evaluated using particle shape, particle size, swelling index, entrapment efficiency, and release assays. RESULTS: The results showed that the polymers have distinct material and physicochemical properties unique to their botanical sources. The microbeads were spherical and free-flowing, and they rolled without friction. The swelling properties ranged from 47.62 ±2.74% to 79.49 ±3.66%. The particle size of the microbeads ranged from 88.14 ±68.57 µm to 214.90 ±66.95 µm, while the encapsulation efficiencies ranged from 20.67 ±4.66% to 83.61 ±6.35%. The dissolution times suggested that the concentration of the natural polymers in the bead formulation could be used to modulate the dissolution properties. Generally, formulations containing the mucilage yielded higher dissolution times than those containing the starch. The kinetics of drug release from the microbeads containing the polymer blends generally fitted the Korsmeyer-Peppas model. The highest similarity was found between formulations C6 and D4 with f2 of 81.07. CONCLUSIONS: The microbeads prepared with polymers obtained from Xanthosoma and Dillenia showed acceptable physicochemical properties, dependent upon polymer type, blend and concentration.


Assuntos
Dilleniaceae/química , Portadores de Fármacos/química , Ibuprofeno/administração & dosagem , Microesferas , Xanthosoma/química , Preparações de Ação Retardada , Tamanho da Partícula , Mucilagem Vegetal/química , Polímeros , Amido/química
5.
J Texture Stud ; 50(2): 148-154, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30548624

RESUMO

Growing interest in processed frozen products with similar characteristics to natural products has generated the study of new products in the food industry field. The characteristics of each matrix, the process of elaboration, composition, and structure of the additives and the interactions amongst these modify the food's texture, structure, physical and sensory properties and, hence, interfere directly with consumer acceptance. This research studied the effect of adding cryoprotectors during frozen storage on the rheological, physicochemical, structural, and microbiological properties in a Mafafa-quinoa-olive oil puree. To carry out the study, the rheological properties were determined through dynamic oscillatory tests and in steady state; likewise, the physicochemical properties (humidity, color, pH, and syneresis) were analyzed. Regarding physicochemical properties, the humidity content in the purees formulated varied between 57 and 74%, without important variation (p > .05) with respect to the formulation, however, in the storage during the freezing/thawing process, this parameter diminished in greater proportion in those purees containing carrageenan as cryoconservant. Both the addition of cryoconservants and the storage time affected significantly (p < .05) the puree's syneresis, with the degree of exudation being lower in the formulation containing xanthan gum at 1% w/w. During the freezing/thawing process, decreased apparent viscosity was noted. Additionally, the analysis of the viscoelastic properties of the purees evidences that already described, given that a significant effect (p < .05) was observed of the formulation of purees in the elastic component G', in contrast with a notable decrease in the viscous component G″.


Assuntos
Fenômenos Químicos , Chenopodium quinoa/química , Crioprotetores/farmacologia , Reologia , Xanthosoma/química , Aditivos Alimentares/farmacologia , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Congelamento , Azeite de Oliva/química , Polissacarídeos Bacterianos , Viscosidade
6.
An Acad Bras Cienc ; 90(2): 1775-1787, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29694497

RESUMO

The objective of this study was to characterize the nutritional compounds of interest present in vegetables known as non-conventional, in Brazil. The following evaluations were carried out: antioxidant activity, phenolic compounds, vitamin C, calories, carbohydrates, humidity, lipids, proteins, fiber, acidity and quantification of minerals (P, K, Ca, Mg, S, Cu, Fe, Mn, Zn and B). The species studied were Amaranthus hybridus L., Amaranthus viridis L., Basella alba L., Eryngium campestre L., Hibiscus sabdariffa L., Lactuca canadensis L., Rumex acetosa L., Stachys byzantina K. Koch, Tropaeolum majus L. and Xanthosoma sagittifolium L. Representative samples of plant structures of interest were harvested from each species suitable for human consumption such as leaves, flowers and flower buds. The results were submitted to multivariate analysis - principal components analysis (PCA). All the species present nutritional compounds of interest in different levels among the evaluated structures.


Assuntos
Flores/química , Magnoliopsida/química , Valor Nutritivo , Brotos de Planta/química , Verduras/química , Amaranthus/química , Antioxidantes/metabolismo , Ácido Ascórbico/análise , Brasil , Caryophyllales/química , Fibras na Dieta/análise , Eryngium/química , Hibiscus/química , Minerais/análise , Fenóis/análise , Folhas de Planta/química , Rumex/química , Stachys/química , Tropaeolum/química , Xanthosoma/química
7.
Drug Res (Stuttg) ; 67(6): 337-342, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28288491

RESUMO

The management of diabetes mellitus (DM) targets glycemic control as well as prevention or reversal of other complications associated with the metabolic disorder. One of such complications is the infertility which has been traced to oxidative stress and DNA damage caused by DM. In this study, experimentally-induced diabetic male Wistar rats were fed with Xanthosoma sagittifolium (cocoyam) for 14 days and its effect on sperm morphology and characteristics, as well as histology of the testes were assessed. X. sagittifolium corm feed (Xs) were reconstituted with commercial rat feed to contain 25, 50, 75 or 100% X. sagittifolium on a weight/weight basis. One primary and 7 secondary cell abnormalities were observed with overall increased total abnormal sperm cells in the diabetic rats. Sperm cell motility was significantly (p<0.05) reduced in all diabetic rats, but diabetic rats fed with Xs showed increased motility and liveability. Sperm volume was unchanged, but the depressed sperm count in the untreated diabetic rats was increased in Xs-fed rats. Histology of Xs-fed diabetic rats showed reduction in seminiferous tubule diameter and luminal diameter which was significantly enlarged in untreated diabetic rats. X. sagittifolium significantly (p<0.05) prevented further deterioration of sperm cell quality and reversed cell apoptosis as presented by increased sperm motility, liveability and count. In the overall, the chances of fertilization by sperm cells from diabetic patients will be increased as well as achievement of good glycemic control and prevention of further damage by the disease condition.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Genitália Masculina/efeitos dos fármacos , Preparações de Plantas/farmacologia , Xanthosoma/química , Aloxano , Animais , Glicemia/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Diabetes Mellitus Experimental/complicações , Relação Dose-Resposta a Droga , Masculino , Medicina Tradicional , Estresse Oxidativo/efeitos dos fármacos , Preparações de Plantas/administração & dosagem , Ratos , Ratos Wistar , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Espermatozoides/metabolismo , Testículo/efeitos dos fármacos
8.
BMC Complement Altern Med ; 16: 9, 2016 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-26753836

RESUMO

BACKGROUND: The present study was designed to investigate the antibacterial activities of the methanol extract of three edible plants, namely Xanthosoma mafaffa, Moringa oleifera and Passiflora edulis and their synergistic effects with some commonly used antibiotics against MDR Gram-negative bacteria expressing active efflux pumps. METHODS: Broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of the extracts, as well as those of antibiotics in association with the extracts. RESULTS: The phytochemical test indicate that all tested crude extracts contained polyphenols, triterpenes and steroids whilst other phytochemical classes were selectively distributed. Extracts showed antibacterial activities with minimum inhibitory concentrations ranging from 128-1024 µg/mL on the majority of the 19 tested Gram-negative bacterial strains. Extract from the pericarp of P. edulis inhibited the growth of 89.5% of the 19 tested bacterial strains, the lowest minimal inhibitory concentration (MIC) value of 128 µg/mL being recorded against Escherichia coli AG100 strain. In the presence of Phenylalanine-Arginine ß-Naphtylamide (PAßN)], an efflux pump inhibitor (EPI), the activity of the extract from X. mafaffa increased on 40% of tested strains. In combination with antibiotics, extracts of X. mafaffa, M. oleifera and pericarp of P. edulis showed synergistic effects with some antibiotics against more than 75% of the tested bacteria. CONCLUSION: The results of the present study indicate that the tested plants may be used in the treatment of bacterial infections including the multi-resistant bacteria.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Moringa oleifera , Passiflora , Extratos Vegetais/farmacologia , Xanthosoma , Colorimetria , Farmacorresistência Bacteriana Múltipla , Sinergismo Farmacológico , Testes de Sensibilidade Microbiana , Moringa oleifera/química , Passiflora/química , Plantas Comestíveis/química , Xanthosoma/química
9.
BMC Complement Altern Med ; 14: 335, 2014 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-25216815

RESUMO

BACKGROUND: Xanthosoma violaceum is commonly observed in fallow areas of Bangladesh but almost no scientific studies exist on this plant. Rural people consume the plant on a frequent basis. The objective of this study was to scientifically analyze the antinociceptive property of methanol extract of aerial parts of the plant along with antihyperglycemic activity. METHODS: Antihyperglycemic activity was measured by oral glucose tolerance test (OGTT). Antinociceptive activity was determined by observed decreases in abdominal constrictions in intraperitoneally administered acetic acid-induced pain model in mice. RESULTS: Administration of methanol extract of aerial parts led to dose-dependent and significant reductions in blood glucose levels in glucose-loaded mice. At doses of 50, 100, 200 and 400 mg per kg body weight, the extract reduced blood sugar levels by 19.3, 23.2, 31.8, and 47.1%, respectively compared to control animals. By comparison, a standard antihyperglycemic drug, glibenclamide, when administered at a dose of 10 mg per kg body weight, reduced blood glucose level by 48.9%. In antinociceptive activity tests, the extract at the above four doses reduced the number of abdominal constrictions by 41.4, 44.8, 48.3, and 55.2%, respectively. A standard pain relieving (antinociceptive) drug, aspirin, reduced the number of writhings by 31.0 and 51.7%, respectively, when administered at doses of 200 and 400 mg per kg body weight. CONCLUSION: To our knowledge, this is the first report on oral glucose tolerance and antinociceptive activity evaluation of aerial parts of the plant. Since the plant is widely available in Bangladesh, the aerial parts can be a readily available source for particularly the rural population for lowering blood sugar in diabetic patients and for alleviating pain.


Assuntos
Analgésicos/administração & dosagem , Diabetes Mellitus/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Dor/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Xanthosoma/química , Analgésicos/isolamento & purificação , Animais , Glicemia/metabolismo , Diabetes Mellitus/metabolismo , Teste de Tolerância a Glucose , Humanos , Hipoglicemiantes/isolamento & purificação , Masculino , Camundongos , Componentes Aéreos da Planta/química , Extratos Vegetais/isolamento & purificação
10.
Int J Biol Macromol ; 65: 222-8, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24463263

RESUMO

This work presents the physicochemical and pasting characterization of isolated mafafa starch and mafafa flour (Xanthosoma robustum). According to SEM images of mafafa starches in the tuber, these starches form Lego-like shaped structures with diameters between 8 and 35 µm conformed by several starch granules of wedge shape that range from 2 to 7 µm. The isolated mafafa starch is characterized by its low contents of protein, fat, and ash. The starch content in isolated starch was found to be 88.58% while the amylose content obtained was 35.43%. X-ray diffraction studies confirm that isolated starch is composed mainly by amylopectin. These results were confirmed by differential scanning calorimetry and thermo gravimetric analysis. This is the first report of the molecular parameters for mafafa starch: molar mass that ranged between 2×10(8) and 4×10(8) g/mol, size (Rg) value between 279 and 295 nm, and molecular density value between 9.2 and 9.7 g/(mol nm(3)). This study indicates that mafafa starch shows long chains of amylopectin this fact contributes to higher viscosity development and higher gel stability. The obtained gel phase is transparent in the UV-vis region. The viscosity, gel stability and optical properties suggest that there is potential for mafafa starch applications in the food industry.


Assuntos
Fenômenos Químicos , Reologia , Amido/química , Xanthosoma/química , Amilopectina/análise , Amilose/análise , Farinha/análise , Fenômenos Ópticos , Temperatura
11.
J Food Sci ; 78(12): H1929-34, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24266602

RESUMO

Several studies have shown that fruits and vegetables contribute to protect against degenerative pathologies such as cardiovascular diseases, diabetes, and cancer, mainly due to the presence of dietary fiber (DF) and polyphenols. Taioba (Xanthosoma sagittifolium) is an edible aroid widely grown in many parts of Africa, America, and Asia. The tubers portions of taioba are widely consumed; however, the leafy portions are generally discarded, despite their high nutritive value. In this study, we have partly characterized the DF of lyophiized taioba leaf (LTL), and assessed the possible protective effects on biochemical parameters and on bile acid (BA) production in colon and cecum, when fed to healthy rats for 4 wk. Forty-five Wistar rats were assigned to either of 5 groups: group 1 received AIN 93G diet (CG: Control); group 2 received AIN 93G containing 2.5% of cellulose + 2.5% inulin (CEIN_5%); group 3 received AIN 93G containing 2.5% of cellulose + 2.5% taioba fiber (CETA_5%); group 4 received AIN 93G containing 5% cellulose + 2.5% taioba fiber (CETA_7.5%); group 5 received AIN 93G containing 5% cellulose + 2.5% of inulin (CEIN_7.5%). LTL showed high contents of total fiber, predominantly comprising insoluble DF with glucose as the major monomer. Rats receiving LTL had increased fecal mass and fat excretion, and improved BA profiles by diminishing the proportion of secondary acids, thus suggesting that consumption of taioba leaf may have the property of lowering the risk of colon cancer.


Assuntos
Compostos Fitoquímicos/farmacologia , Folhas de Planta/química , Xanthosoma/química , Animais , Ácidos e Sais Biliares/metabolismo , Ceco/metabolismo , Celulose/análise , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Colo/metabolismo , Fezes/química , Insulina/sangue , Inulina/análise , Valor Nutritivo , Ratos , Ratos Wistar , Triglicerídeos/sangue
12.
J Nat Prod ; 74(5): 969-75, 2011 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-21520894

RESUMO

Bacterial infections directly affect the world's population, and this situation has been aggravated by indiscriminate use of antimicrobial agents, which can generate resistant microorganisms. In this report, an initial screening of proteins with antibacterial activity from corms of 15 species of the Xanthosoma genus was conducted. Since Xanthosoma blandum corms showed enhanced activity toward bacteria, a novel protein with bactericidal activity was isolated from this particular species. Edman degradation was used for protein N-termini determination; the primary structure showed similarities with Kunitz inhibitors, and this protein was named Xb-KTI. This protein was further challenged against serine proteinases from different sources, showing clear inhibitory activities. Otherwise, no hemolytic activity was observed for Xb-KTI. The results demonstrate the biotechnological potential of Xb-KTI, the first proteinase inhibitor with antimicrobial activity described in the Xanthosoma genus.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Peptídeos/isolamento & purificação , Peptídeos/farmacologia , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Xanthosoma/química , Sequência de Aminoácidos , Antibacterianos/química , Testes de Sensibilidade Microbiana , Peptídeos/química , Proteínas de Plantas/química , Serina Endopeptidases/metabolismo , Xanthosoma/genética
13.
J Food Sci ; 72(6): S367-72, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17995692

RESUMO

The physical proximate composition and physicochemical characteristics, microbiological stability, and in vitro alpha-amylolysis rate of flours produced by conventional dehydration techniques of the edible portions of the aroids Xanthosoma sagittifolium and Colocasia esculenta were investigated. Flours from the edible portion of both tubers did not show significant statistical differences in moisture, Aw, crude protein, total sugars, amylose, and amylopectin contents. C. esculenta flour showed higher crude fat, total, soluble, and insoluble dietary fiber, and mineral (P, Ca, Fe, and Zn) contents, whereas X. sagittifolium flour showed higher starch, ash, and reducing sugar content than its counterpart. With regard to physical and physicochemical characteristics, X. sagittifolium flour showed higher titratable acidity and relative density values, being darker and more yellowish than its counterpart. On the other hand, X. sagittifolium flour showed higher gelatinization temperature than C. esculenta flour. Parameters such as viscosity during the holding time (95 degrees C for 30 min), viscosity at 50 degrees C, setback, and consistency were lower in C. esculenta flour than X. sagittifolium flour. The viscosity peak and breakdown indexes were higher in C. esculenta flour than in the X. sagittifolium sample. The colony forming units (CFU) of the microorganisms were much lower than those reported in the literature for similar products. Moreover, due to their moisture content and water activity, these flours could be classified as dry foods and they are shelf-stable foods. The results reflect that flours with good chemical, physicochemical, and nutritional quality and satisfactory microbiological stability may be produced from these aroids.


Assuntos
Colocasia/química , Farinha , Manipulação de Alimentos/métodos , Xanthosoma/química , Fenômenos Químicos , Físico-Química , Qualidade de Produtos para o Consumidor , Carboidratos da Dieta/análise , Gorduras na Dieta/análise , Fibras na Dieta/análise , Proteínas Alimentares/análise , Farinha/análise , Farinha/microbiologia , Farinha/normas , Tecnologia de Alimentos , Géis , Humanos , Valor Nutritivo , Reologia , Viscosidade
14.
Bull Environ Contam Toxicol ; 79(4): 377-9, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17673943

RESUMO

Cocoyam (Xanthosoma sagititolium) and Watercocoyam (Colocasia esculenta) have gained increased importance in the diets of majority of people in developing countries such as Ghana. The concentration levels of arsenic, cadmium, and mercury in Cocoyam (X. sagititolium) and Watercocoyam (C. esculenta) in Tarkwa and its surrounding villages a mining community in Ghana were measured in this study. From the results of the study, the levels of arsenic, cadmium and mercury in X. sagititolium and C. esculenta were higher than the WHO recommended levels. These root tubers absorb or uptake toxic chemicals from the soil as a result of the mining operations. This means that, the consumption of X. sagititolium and C. esculenta by humans from such environments may pose a serious health risk. There is therefore the need for a concerted effort by all to minimize the negative impact of gold mining in the study area.


Assuntos
Cádmio/análise , Colocasia/química , Contaminação de Alimentos/análise , Mercúrio/análise , Mineração , Poluentes do Solo/análise , Xanthosoma/química , Arsênio/análise , Arsênio/toxicidade , Cádmio/toxicidade , Exposição Ambiental , Gana , Humanos , Mercúrio/toxicidade , Poluentes do Solo/química , Poluentes do Solo/toxicidade
15.
Int J Vitam Nutr Res ; 75(2): 161-8, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15929638

RESUMO

The present study investigated the effect of malanga leaf powder and its carotenoids oil extract on oxidative damage in rat tissues. A group of rats received AIN-93G diet devoid of vitamin A (AD) and three other groups were treated with AD diet supplied with synthetic beta-carotene (beta-car) or malanga leaf powder (MP) or malanga carotenoids extract (CE). The diets' carotenoids bioavailability was determined through carotenoids intake/liver retinol content. Lipid thiobarbituric acid reactive substances (TBARS) and protein (carbonyl) oxidation, and reduced (GSH) and oxidized (GSSG) glutathione concentrations were determined in liver, heart, and brain. Synthetic beta-carotene bioavailability was higher than that of pro-vitamin A carotenoids from MP and CE diets, and no difference was observed between the latter two groups. Liver and heart lipid peroxidation was lower in the beta-car and CE groups than the AD group, while no difference was observed for the MP group. The beta-car, MP, and CE groups showed lower liver protein oxidation than the AD group, and only the CE group had lower heart protein oxidation in relation to AD. The MP group had a lower liver GSSG concentration and higher GSH/GSSG ratio than the AD group, while no difference was observed for heart glutathione concentration among the groups. The results indicate that at physiological levels, beta-car, malanga carotenoids extract, and malanga leaf powder have antioxidant effects in rats.


Assuntos
Carotenoides/farmacologia , Dieta , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/química , Xanthosoma/química , Animais , Peso Corporal , Carotenoides/administração & dosagem , Carotenoides/farmacocinética , Ingestão de Alimentos , Glutationa/análise , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/química , Masculino , Oxirredução , Proteínas/química , Ratos , Ratos Wistar , Vitamina A/análise
16.
Ann Nutr Metab ; 48(4): 288-95, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15452401

RESUMO

AIM: This study examined the ability of tropical vegetables to reduce oxidative stress induced by vitamin A deficiency. METHODS: Vitamin A-deficient male Wistar rats were divided into four groups which were treated for 30 days with different diets: AIN-93G vitamin A-deficient diet (DD), DD supplemented with pure beta-carotene (beta-D) and DD supplemented with malanga (Xanthosoma sagittifolium) (MD) or purslane (Portulaca oleracea) (PD) leaves as the only source of vitamin A. The thiobarbituric acid-reactive substances (TBARS), reduced (GSH) and oxidized (GSSG) glutathione, and antioxidant enzyme activities were determined in the heart and liver. RESULTS: The rats fed beta-D, MDand PD showed liver and heart TBARS concentrations lower than did DD rats. The liver GSH concentration of beta-D, MD and PD rats was lower compared to DD rats. The heart GSSG concentration of the vegetable groups was significantly lower than in DD rats. Liver and heart catalase activities were not significantly different among the groups, nor was heart glutathione peroxidase (GPX) activity, however the beta-D rats showed the highest liver GPX activity. There was no difference in liver glutathione-S-transferase level among the groups, while heart activity was higher in rats fed the vegetable leaves. CONCLUSION: This study evidences that the ingestion of purslane or malanga leaves may have a protective effect against oxidative stress caused by vitamin A deficiency.


Assuntos
Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Portulaca/química , Deficiência de Vitamina A/metabolismo , Xanthosoma/química , Animais , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Fígado/enzimologia , Fígado/metabolismo , Masculino , Miocárdio/enzimologia , Miocárdio/metabolismo , Oxirredução , Folhas de Planta , Distribuição Aleatória , Ratos , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico/análise
17.
J Agric Food Chem ; 51(22): 6423-8, 2003 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-14558757

RESUMO

An extract of Xanthosoma violaceum leaves was subjected to a polyphenol profile determination, including total polyphenols, and antioxidant activity evaluation. Analysis of the extract resulted in the isolation of a new flavone C-glycoside, apigenin 6-C-beta-D-glucopyranosyl-8-C-beta-D-apiofuranoside (1), as well as known flavone C-glycosides, including vitexin (2), isovitexin (3), isovitexin 4'-O-rhamnopyranoside (4), apigenin 6-C-[beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside] (5), and apigenin 6,8-diC-beta-D-glucopyranoside (6). The antioxidant activity of the extract was assessed by means of two different in vitro tests: bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH test) and peroxidation induced by the water-soluble radical initiator 2,2'-azobis(2-amidinopropane) hydrochloride, on mixed dipalmitoylphosphatidylcholine/linoleic acid unilamellar vesicles (LP-LUV test). In both tests used, the extract and a fraction II showed a significant antioxidant/free-radical scavenging effect (fraction II, EC(50) = 11.6 microg/mL) in comparison to alpha-tocopherol (EC(50) = 10.1 microg/mL).


Assuntos
Antioxidantes/farmacologia , Apigenina , Fenóis/análise , Fenóis/farmacologia , Folhas de Planta/química , Xanthosoma/química , Compostos de Bifenilo , Flavonoides/análise , Flavonoides/farmacologia , Sequestradores de Radicais Livres/farmacologia , Glicosídeos , Monossacarídeos/análise , Monossacarídeos/farmacologia , Peróxidos/química , Picratos/química , Extratos Vegetais/farmacologia
18.
J Agric Food Chem ; 51(18): 5510-5, 2003 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-12926906

RESUMO

Starch-modifying processes, such as pyrodextrinization, are potential ways to alter the nutritional features of this polysaccharide. A widely used method for pyrodextrinizing maize starch was also applied to lentil, sorghum, cocoyam, sagu, and cassava starches, and the in vitro digestibility of the products was evaluated. Pyrodextrins were produced by heating starch at 140 degrees C for 3 h, with catalytic amounts of HCl. The enzymatically available starch content of all preparations decreased by 55-65% after modification. Thus, pyrodextrinization seems to be an effective way to produce indigestible glucans from different starches. Pyrodextrins obtained were complex mixtures of starch derivatives with a wide range of molecular weight as estimated by gel filtration chromatography. Both their molecular weight profiles and contents of indigestible fractions varied with starch source. Experiments with lentil and cassava starches showed that changing dextrinization conditions also affects the susceptibility to enzymatic hydrolysis of the product.


Assuntos
Dextrinas/química , Digestão , Temperatura Alta , Plantas/química , Amido/química , Fenômenos Químicos , Físico-Química , Fabaceae/química , Manihot/química , Raízes de Plantas/química , Poaceae/química , Sementes/química , Xanthosoma/química , Zea mays/química
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