RESUMO
This work aimed to investigate the phytochemical composition, nutritional value, antioxidant, antihemolytic, antihyperglycemic, and antiproliferative activities of flaxleaf fleabane (Conyza bonariensis) leaves. Different concentrations of water and ethanol (0:100, 25:75, 50:50, 75:25, and 100:0 v/v) were used in the extraction process and results showed that the hydroalcoholic extract (50:50 v/v) presented the highest total phenolics, ortho-diphenolics, Folin-Ciocalteu reducing capacity, FRAP, and Fe2+ chelating ability values. Flaxleaf fleabane leaves (FFL) contained 19.6 g/100 g of fibers and 26 g/100 g of proteins. Ellagic acid, procyanidin A2, caffeic, rosmarinic, gallic, and 2,5-dihydroxybenzoic acids were the main phenolics. This phenolic-rich extract inhibited the lipid oxidation of Wistar rat brain (IC50 = 863.0 mg GAE/L), inhibited α-glucosidase activity (IC50 = 435.4 µg/mL), protected human erythrocytes against mechanical hemolysis at different osmolarity conditions, and showed cytotoxic/antiproliferative effects against human ileocecal adenocarcinoma cells (HCT8; IC50 = 552.6 µg/mL) but no cytotoxicity toward noncancerous human lung fibroblast (IMR90). Overall, FFL showed potential to be explored by food companies to be a source of proteins, natural color substances, and phenolic compounds. PRACTICAL APPLICATION: Flaxleaf fleabane leaves (FFL) are usually burnt or partially given to cattle, without a proper utilization as a source of nutrients for human nutrition. Here, we studied the nutritional composition, phenolic composition, and toxicological aspects of FFL using different biological protocols. FFL was proven to be a rich source of proteins and dietary fibers and showed antioxidant activity measured by chemical and in vitro biological assays. Additionally, as it did protected human red cells and did not show cytotoxicity, we assume FFL has relative safety to be consumed as a nonconventional edible plant.
Assuntos
Conyza/química , Compostos Fitoquímicos/análise , Animais , Antioxidantes/análise , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Conyza/metabolismo , Alimento Funcional/análise , Inibidores de Glicosídeo Hidrolases/análise , Inibidores de Glicosídeo Hidrolases/metabolismo , Inibidores de Glicosídeo Hidrolases/farmacologia , Humanos , Valor Nutritivo , Fenóis/análise , Fenóis/metabolismo , Fenóis/farmacologia , Compostos Fitoquímicos/metabolismo , Compostos Fitoquímicos/farmacologia , Folhas de Planta/química , Folhas de Planta/metabolismo , Plantas Comestíveis/química , Plantas Comestíveis/metabolismo , Ratos , Ratos Wistar , alfa-Glucosidases/químicaRESUMO
Most aroma compounds exist in vegetal tissues as disaccharide conjugates, rutinose being an abundant sugar moiety in grapes. The availability of aroma precursors would facilitate analytical analysis of plant-based foods. The diglycosidase α-rhamnosyl-ß-glucosidase from Acremonium sp. DSM 24697 efficiently transglycosylated the rutinose moiety from hesperidin to 2-phenylethanol, geraniol, and nerol in an aqueous-organic biphasic system. 2-Phenethyl rutinoside was synthesized up to millimolar level with an 80% conversion regarding the donor hesperidin. The hydrolysis of the synthesized aroma precursors was not detected in an aqueous medium. However, in the presence of ethanol as a sugar acceptor, the enzyme was able to transfer the disaccharide residue forming the alkyl-rutinoside. The aroma precursors were significantly hydrolyzed (up to 3-4% in 2 h at 30 °C), which indicated the potential use of the enzyme for biotechnological applications, for example, in aroma modulation of fermented foods.
Assuntos
Glucosidases/metabolismo , Plantas Comestíveis/química , Plantas Comestíveis/metabolismo , Dissacarídeos/metabolismo , Análise de Alimentos , Tecnologia de Alimentos , Glicosilação , Hesperidina/metabolismo , Odorantes/análiseRESUMO
Diversity of Pink-Pigmented Facultative Methylotrophs (PPFMs) in phyllosphere of cotton, maize and sunflower was determined based on differential carbon-substrate utilization profile and Random Amplified Polymorphic DNA data. Results indicate that six diversified groups of PPFMs are found in these crops. Sunflower and maize phyllosphere harbor four different groups of methylobacteria while cotton has only two groups.
A diversidade de microrganismos metilotróficos facultativos pigmentados (PPFMs) na filosfera de algodão, milho e girassol foi determinada baseada no perfil diferencial de utilização de substratos de carbono e em dados de RAPD. Os resultados indicaram a existência de seis grupos diferentes de PPFMs nessas plantas. As filosferas de girassol e milho apresentaram quatro grupos diferentes de metilobactérias enquanto a de algodão apresentou apenas dois grupos.
Assuntos
Carbono , Técnicas In Vitro , Methylobacterium/genética , Methylobacterium/metabolismo , Plantas Comestíveis/genética , Plantas Comestíveis/metabolismo , Técnica de Amplificação ao Acaso de DNA Polimórfico , Substratos para Tratamento Biológico , Biodiversidade , MétodosRESUMO
The alcoholic beverage parakari is a product of cassava (Manihot esculenta Crantz) fermentation by Amerindians of Guyana. While fermented beverage production is nearly universal among indigenous Amazonians, parakari is unique among New World beverages because it involves the use of an amylolytic mold (Rhizopus sp., Mucoraceae, Zygomycota) followed by a solid substratum ethanol fermentation. The mycological significance of this dual fermentation process previously was unrecognized. A detailed study of parakari fermentation was made in the Wapisiana Amerindian village of Aishalton, South Rupununi, Guyana. Thirty steps were involved in parakari manufacture, and these exhibited a high degree of sophistication, including the use of specific cassava varieties, control of culture temperature and boosting of Rhizopus inoculum potential with purified starch additives. During the fermentation process, changes in glucose content, pH, flavor, odor and culture characteristics were concomitant with a desirable finished product. Parakari is the only known example of an indigenous New World fermentation that uses an amylolytic mold, likely resulting from domestication of a wild Rhizopus species in the distant past. Parakari production is remarkably similar to dual fermentations of Asia, yet it was independently derived.
Assuntos
Bebidas , Glucose/metabolismo , Manihot/metabolismo , Rhizopus/metabolismo , Amido/metabolismo , Fermentação , Guiana , Manihot/química , Plantas Comestíveis/metabolismo , Rhizopus/crescimento & desenvolvimento , Rhizopus/isolamento & purificaçãoRESUMO
The performance and gut measurements of broilers fed on diets containing different amounts of chaya (Cnidoscolus aconitifolius) leaf meal (CLM) were examined in two experiments. In the first experiment, 60 Hubbard chickens (30 males and 30 females; 2 weeks old) were fed on five maize diets; these were formulated using 0, 150 (CLM150), 250 (CLM250) or 350 (CLM350) g CLM/kg, and the fifth diet contained soyabean. In the second experiment, 148 Ross male chicks, 1 day old, were fed on three isonitrogenous and isoenergetic maize-soyabean-based diets, which included 0 (control), 150 (C150) or 250 (C250) g CLM/kg. The diets were offered ad libitum for 2 or 3 weeks in the first and second experiments, respectively. Food intake, weight gain and the food:weight gain ratio were recorded. The weight of the gizzard and intestine and the weight and length of the caeca were also determined in the second experiment. In experiment 1, the birds fed on the maize-soyabean diet had a higher (p < 0.05) weight gain and final weight than birds fed on maize only or on the CLM150 diets. There were no differences for any of the variables studied between the birds fed on the maize-soyabean diet and those fed on the CLM250, nor between males and females. In the second experiment, weight gain, food intake and the food:weight gain ratio for birds fed on C250 were lower (p < 0.05) than those in birds fed on either the control or C150 diets. The weights of the gizzard and intestine were the lowest and the highest, respectively, in birds fed on C250 (p < 0.05). The length and weight of the caecum from birds fed on the control diet were lower (p < 0.05) than those of birds fed on either the C150 or C250 diets. The results from this study suggest that CLM may be included up to 150 g/kg in commercial diets without having an adverse effect on poultry performance, and may also be mixed with maize up to 250 g/kg to improve the performance of chickens fed on low-protein diets.
Assuntos
Ração Animal , Galinhas/metabolismo , Plantas Comestíveis/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Peso Corporal/fisiologia , Ceco/fisiologia , Galinhas/crescimento & desenvolvimento , Ingestão de Alimentos , Euphorbiaceae , Feminino , Masculino , México , Folhas de Planta/metabolismo , Distribuição AleatóriaRESUMO
The report presented in the 7th ONU's Conference (USA, 2001) about climatic changes that took place at the end of 2001 informs that, in less than 50 years, more than 45% of the world population will be suffering from lack of water. This fact occurs by the absence of management on water resources, mainly, in agriculture. As the excess as the lack of humidity in soil can change the harvest quality, causing physiologic anomalies in food and promoting soil diseases incidence caused by bacteria and fungus. In order to establish a larger control in the food quality, a study has been performed, through the neutron radiographic technique, that proposes the optimization of agricultural harvests in relation to the minimum quantity of water necessary for the plant to develop and, also, of the soil compactness. Thus, neutron radiographic images of the system root-soil can be produced so that each root will be evaluated for its ability to penetrate in the soil layers, having the advantage of not interfering in this system what it is not possible through the usual techniques yet. The initial tests using bean roots showed that the soil thickness, which involved the roots, resulted in low contrast images, what impeded their visualization with enough clearness so that their grow could not be observed. For this reason, it was opted to the gadolinium as a contrast agent so that we have been studying its transport through the roots.
Assuntos
Agricultura/métodos , Plantas Comestíveis/crescimento & desenvolvimento , Meios de Contraste , Gadolínio/farmacocinética , Umidade , Nêutrons , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plantas Comestíveis/metabolismo , Solo/análise , Abastecimento de ÁguaRESUMO
The identification and characterization of differential gene expression from tissues subjected to stress has gained much attention in plant research. The recognition of elements involved in the response to a particular stress enhances the possibility of promoting crop improvement through direct genetic modification. However, the performance of some of the 'first generation' of transgenic plants with the incorporation of a single gene has not always been as expected. These results have stimulated the development of new transgenic constructions introducing more than one gene and capable of modifying complex pathways. Several techniques are available to conduct the analysis of gene regulation, with such information providing the basis for novel constructs specifically designed to modify metabolism. This review deals with techniques that allow the identification and characterization of differentially-expressed genes and the use of molecular pathway information to produce transgenic plants.
Assuntos
Regulação da Expressão Gênica de Plantas , Plantas Comestíveis/genética , Plantas Geneticamente Modificadas/genética , Impressões Digitais de DNA , DNA de Plantas/genética , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Genoma de Planta , Estresse Oxidativo , Plantas Comestíveis/metabolismo , Plantas Geneticamente Modificadas/metabolismoRESUMO
Plant-food-derived antioxidants and active principles such as flavonoids, hydroxycinnamates (ferulic acid, chlorogenic acids, vanillin etc.), beta-carotene and other carotenoids, vitamin E, vitamin C, or rosemary, sage, tea and numerous extracts are increasingly proposed as important dietary antioxidant factors. In this endeavor, assays involving oxidative DNA damage for characterizing the potential antioxidant actions are suggested as in vitro screens of antioxidant efficacy. The critical question is the bioavailability of the plant-derived antioxidants.
Assuntos
Antioxidantes , Dano ao DNA , Estresse Oxidativo , Plantas Comestíveis/química , Antioxidantes/análise , Antioxidantes/metabolismo , Cobre/metabolismo , Adutos de DNA/análise , Adutos de DNA/genética , Nitratos/antagonistas & inibidores , Nitratos/metabolismo , Fenantrolinas/metabolismo , Plantas Comestíveis/metabolismoRESUMO
Crop residues, such as sugar cane bagasse (SCB), have been largely used for cattle feeding. However, the close association that exists among the three major plant cell-wall components, cellulose, hemicellulose, and lignin, limits the efficiency by which ruminants can degrade these materials. Previously, we have shown that pretreatment with 3% (w/w) phosphoric acid, under relatively mild conditions, increased considerably the nutritional value for SCB. However, in this preliminary study, pretreated residues were not washed prior to in situ degradability assays because we wanted to explore the high initial solvability of lowmol-wt substances that were produced during pretreatment. We have now studied the suitability of water-and/or alkali-washed residues to in situ ruminal digestion. Alkali washing increased substrate cellulose content by removing most of the lignin and other residual soluble substances. As a result the ruminal degradability of these cleaner materials had first-order rate constants five times higher than those substrates with higher lignin content (e.g., stem-exploded bagasse). However, alkali washing also increased the time of ruminal lag phase of the cellulosic residue, probably because of hemicellulose and/or lignin removal and to the development of substrates with higher degree of crystallinity. Therefore, longer lag phases appear to be related to low microbial adherence after extensive water and alkali extraction, as Novell as to the slower process of cellulase induction during ruminal growth. The kinetic data on ruminal digestion were shown to be very well adjusted by a nonlinear model. Although pretreatment enhances substrate accessibility, the occurrence of an exceedingly high amount of lignin byproducts within the pretreated material reduces considerably its potential degradability.
Assuntos
Bovinos/metabolismo , Dieta , Digestão/fisiologia , Plantas Comestíveis/metabolismo , Álcalis , Animais , Estudos de Avaliação como Assunto , Cinética , Modelos Lineares , Ácidos Fosfóricos , Espectrofotometria , VaporRESUMO
The study of Atriplex suberecta leaf protein concentrate has been included within our work line entitled "Biological value of the leaf protein of Atriplex" amino acid profile and chemical score. In order to evaluate nitrogen retention, net protein utilization (NPU), true digestibility (TD) and biological value (BV) data were obtained. Weight gain was studied after determining net protein ratio (NPR) and relative net protein ratio (RNPR) with the following results: CS = 96, calculated for sulphur amino acids; NPU = 60 +/- 4.00; TD = 76 +/- 5.20; BV = 87; NPR = 3.34 +/- 2.50 and RNPR = 88%, which enable us to infer that its protein is of good quality. These data, therefore, should indicate that the product studied could be a good complement for cereals, considering its high lysine content (CS superior to 100).