Proteic and phenolics compounds contents in Bacupari callus cultured with glutamine and nitrogen sources / Conteúdo de proteínas e compostos fenólicos em calos de Bacupari cultivados com glutamina e fontes de nitrogênio

Abstract In this study was evaluated the influence of glutamine supplementation on the endogenous content of amino acids, proteins, total phenolics, flavonoids and proanthocyanidins in Bacupari callus. The explants were inoculated in MS medium, MS with half concentration of the nitrogen salts (MS½) and nitrogen-free MS, supplemented with glutamine (5, 10, 30 and 60mM) named as Gln5, Gln10, Gln30 and Gln60. Amino acids and proteins were analyzed after 20, 80 and 140 days and the secondary metabolites on the 140th day. There was no difference in the amino acids on the 20th day. On the 80th day the treatments MS and MS½ presented the lowest levels. On the 140th day MS and MS½ presented the lowest amino acid concentration and Gln10 the highest. Concerning proteins, there was difference only on the 140th day, being the highest concentrations observed in Gln5, and the lowest in MS½ treatment. Total phenolics content was higher in the treatment Gln60 and lowest in MS. Treatments Gln5, Gln10, Gln30 and MS½ were statistically equal. For flavonoids, the highest values occurred in the treatments Gln30, Gln60 and MS½ and the lowest in Gln5, Gln10 and MS. Similarly, for the proanthocyanidins the highest concentrations were observed in treatment Gln60 and the lowest in Gln5 and MS. In conclusion, the treatment with 60mM of glutamine favors the protein accumulation and production of secondary metabolites in Bacupari callus.

Resumo Nesse estudo foi avaliado o efeito da suplementação com glutamina no conteúdo endógeno de aminoácidos, proteínas, fenólicos totais, flavonoides e proantocianidinas em calos de Bacupari. Os explantes foram inoculados em meio MS, meio MS com metade da concentração de dos sais de nitrogênio (MS½) e meio MS sem nitrogênio suplementado com glutamina (5, 10, 30 e 60mM) denominados como Gln5, Gln10, Gln30 e Gln60. Os aminoácidos e as proteínas foram analisados após 20, 80 e 140 dias e os metabólitos secundários no 140° dia. Não houve diferença nos aminoácidos no 20° dia. No 80° dia os tratamentos MS e MS½ apresentaram os menores níveis. No 140° dia, MS e MS½ apresentaram as menores concentrações de aminoácidos e o Gln10 as maiores. A respeito das proteínas, houve diferença apenas no 140° dia, sendo as maiores concentrações observadas nos tratamentos Gln, e as menores no MS½. O conteúdo de fenólicos totais foi maior no tratamento Gln60 e menor no MS. Os tratamentos Gln5, Gln10, Gln30 e MS½ foram estatisticamente iguais. Para os flavonóides, os maiores valores ocorreram nos tratamentos Gln30, Gln60 e MS½ e os menores no Gln5, Gln10 e MS. Da mesma forma, para as proantocianidinas, as maiores concentrações foram observadas no tratamento Gln60 os menores no Gln5 e MS. Em conclusão, o tratamento com 60 mM de glutamina favorece o acúmulo de proteínas e a produção de metabólitos secundários em calos de Bacupari.

Proteomic profile of Piper tuberculatum (Piperaceae) / Perfil proteômico e metabólico de Piper tuberculatum (Piperaceae)

Abstract Piper tuberculatum (Piperaceae) is a species that accumulates especially amides as secondary metabolites and several biological activities was previously reported. In this article, we report a proteomic study of P. tuberculatum. Bidimensional electrophoresis (2D SDS-PAGE) and mass spectrometry (ESI-Q-TOF) were used in this study. Over a hundred spots and various peptides were identified in this species and the putative functions of these peptides related to defense mechanism as biotic and abiotic stress were assigned. The information presented extend the range of molecular information of P. tuberculatum.

Resumo Piper tuberculatum (Piperaceae) é uma espécie que acumula especialmente amidas como metabólitos secundários e diversas atividades biológicas dessa espécie foram relatadas anteriormente. No presente artigo, relatamos um estudo proteômico dessa espécie. Eletroforese bidimensional (2D SDS-PAGE) e espectrometria de massas (ESI-Q-TOF) foram utilizadas nesse estudos. Mais de cem spots e vários peptídeos foram identificados nesta espécie e as funções putativas desses peptídeos relacionadas a mecanismo de defesa como estresse biótico e abiótico foram atribuídos. As informações apresentadas ampliam a gama de informações moleculares dessa espécie.

Plant antiherbivore defenses in Fabaceae species of the Chaco / Defesas das plantas anti-herbivoria em espécies de Fabaceae do Chaco

Abstract The establishment and maintenance of plant species in the Chaco, one of the widest continuous areas of forests in the South American with sharp climatic variations, are possibly related to biological features favoring plants with particular defenses. This study assesses the physical and chemical defenses mechanisms against herbivores of vegetative and reproductive organs. Its analyses of 12 species of Fabaceae (Leguminosae) collected in remnants of Brazilian Chaco shows that 75% present structural defense characters and 50% have chemical defense - defense proteins in their seeds, like protease inhibitors and lectins. Physical defenses occur mainly on branches (78% of the species), leaves (67%), and reproductive organs (56%). The most common physical characters are trichomes and thorns, whose color represents a cryptic character since it does not contrast with the other plant structures. Defense proteins occur in different concentrations and molecular weight classes in the seeds of most species. Protease inhibitors are reported for the first time in seeds of: Albizia niopoides, Anadenanthera colubrina, Mimosa glutinosa, Prosopis rubriflora, and Poincianella pluviosa. The occurrence of physical and chemical defenses in members of Fabaceae indicate no associations between defense characters in these plant species of the Chaco.

Resumo O estabelecimento e a manutenção de espécies no Chaco, uma planície semi-árida da América do Sul com variações climáticas importantes, possivelmente estão relacionados a características biológicas que favorecem as plantas detentoras de defesas particulares. Este estudo teve como objetivos avaliar os mecanismos de defesa física e química anti-herbivoria em órgãos vegetativos e reprodutivos. Analisamos 12 espécies da família Fabaceae (Leguminosae) obtidas em remanescentes de Chaco brasileiro. Observamos que 75% das espécies estudadas apresentam atributo de defesa física e 50% possuem defesa química - proteínas de defesa nas sementes, como inibidores de protease e lectinas. As defesas físicas ocorrem principalmente nos ramos (78% das espécies), nos órgãos reprodutivos (56% das espécies) e nas folhas (67%). Os atributos físicos mais frequentes são tricomas e espinhos, cuja coloração não contrastante com as demais estruturas das plantas representa um caráter críptico. Proteínas de defesa ocorrem nas sementes da maioria das espécies, com diferentes concentrações e classes de pesos moleculares. Inibidores de protease nas sementes estão sendo relatados pela primeira vez em: Albizia niopoides, Anadenanthera colubrina, Mimosa glutinosa, Prosopis rubriflora e Poincianella pluviosa. A ocorrência de defesas física e química entre os membros de Fabaceae indica que não há associações entre as características de defesa das espécies de plantas avaliadas no Chaco.

Dark septate endophyte decreases stress on rice plants

Abstract Abiotic stress is one of the major limiting factors for plant development and productivity, which makes it important to identify microorganisms capable of increasing plant tolerance to stress. Dark septate endophytes can be symbionts of plants. In the present study, we evaluated the ability of dark septate endophytes isolates to reduce the effects of water stress in the rice varieties Nipponbare and Piauí. The experiments were performed under gnotobiotic conditions, and the water stress was induced with PEG. Four dark septate endophytes were isolated from the roots of wild rice (Oryza glumaepatula) collected from the Brazilian Amazon. Plant height as well as shoot and root fresh and dry matter were measured. Leaf protein concentrations and antioxidant enzyme activity were also estimated. The dark septate endophytes were grown in vitro in Petri dishes containing culture medium; they exhibited different levels of tolerance to salinity and water stress. The two rice varieties tested responded differently to inoculation with dark septate endophytes. Endophytes promoted rice plant growth both in the presence and in the absence of a water deficit. Decreased oxidative stress in plants in response to inoculation was observed in nearly all inoculated treatments, as indicated by the decrease in antioxidant enzyme activity. Dark septate endophytes fungi were shown to increase the tolerance of rice plants to stress caused by water deficiency.

Proteomic analysis of latex from Jatropha curcas L. stems and comparison of two classic proteomic sample isolation methods: the phenol extraction and the TCA/acetone extraction

Background: Jatropha curcas is a wide-spreading latex-rich biodiesel plant with high oil content in seeds that have always been under intense studies. However, studies are lacking on the latex component that is considered rich in proteins with potentially important physiological functions and secondary metabolites that are a promising source for new drugs. The proteomic analysis, which would be the first step to study these substances, was hampered by the presence of interfering components. Phenol extraction and Trichloroacetic acid (TCA)/ acetone extraction, two major plant proteomic isolation methods, were used and compared in this study. Results: We identified 459 proteins from the J. curcas latex proteome using the combination of the two extraction techniques. Although more number of latex proteins were identified by the phenol extraction (401 proteins vs. 123 proteins by the TCA/acetone extraction), only 65 proteins were commonly isolated by both methods. Analysis of the biochemical properties revealed that relatively more number of lower isoelectric point (pI) proteins were isolated by the TCA/acetone method (pI mode: 4.79, 6.51 for phenol). Moreover, GO, COG, and KEGG analyses showed that certain classes/categories/pathways annotated more number of proteins than others, and most of them had proportionally comparable protein counts by both the methods, however, with exemplified exceptions. Conclusions: A large number of proteins were found and exclusively identified by either method, indicating that a better proteome coverage of plant samples in a similar context needs the combined use of multiple isolation methods. In addition, the core biological function of the latex may be uncovered by certain GO, COG, and KEGG classes/categories/pathways that annotate more proteins.

Measurement of expansin activity and plant cell wall creep by using a commercial texture analyzer

Background: Expansins play an important role in cell wall metabolism and fruit softening. Determination of expansin activity is a challenging problem since it depends on measuring cell wall properties by using ad hoc extensometers, a fact that has strongly restricted its study. Then, the objective of the work was to adapt a methodology to measure cell wall creep and expansin activity using a commercial texture meter, equipped with miniature tensile grips and an ad hoc cuvette of easy construction. Results: It was possible to measure hypocotyls acid growth and expansin activity in a reliable and reproducible way, using a commercial texture meter, common equipment found in laboratories of food science or postharvest technology. Expansin activity was detected in protein extracts from cucumber hypocotyls, tomato and strawberry fruits, and statistical differences in expansin activity were found in both fruit models at different ripening stages. Conclusions: The possibility of measuring expansin activity following this adapted protocol with a commercial texture meter could contribute to ease and increase the analysis of expansin in different systems, leading to a better understanding of the properties of these proteins under different experimental conditions.

In silico structural and functional analysis of protein encoded by wheat early salt-stress response gene (WESR3).

Salt stress is one of the major abiotic stresses limiting grain yield in wheat (Triticum aestivum L.). Wheat early salt-stress response gene (WESR3) is one of the major salt stress genes, which is affected in the first phase of salt stress. In this study, sequence and structural analysis of protein coded by WESR3 gene was carried out using various bioinformatics tools. Sequence analysis of WESR3 protein revealed the presence of highly conserved regions of Mlo gene family. Three-dimensional modeling was carried out to elucidate its structure and its active site. The sequence analysis revealed that WESR3 protein might be involved in fungal pathogen attack pathway. Thus, in addition to its involvement in abiotic stresses, it also seemed to play an important part in biotic stress pathways. Out of the three modeled protein structures obtained from I-TASSER, HHPred and QUARK, the I-TASSER protein model was the best model based on high confidence score and lesser number of bad contacts. The Ramchandran plot analysis also showed that all amino acid residues of I-TASSER model lie in the allowed region and thus indicating towards the overall good quality of the predicted model. Seventeen active sites were predicted in the protein bearing resemblance to the Mlo family conserved regions. In conclusion, a detailed analysis of WESR3 protein suggested an important role of WESR3 in biotic and abiotic stress. These results aid to the experimental data and help to build up a complete view of WESR3 proteins and their role in plant stress response.

Experimental infection with the Toxoplasma gondii ME-49 strain in the Brazilian BR-1 mini pig is a suitable animal model for human toxoplasmosis

Toxoplasma gondii causes toxoplasmosis, a worldwide disease. Experimentation with pigs is necessary for the development of new therapeutic approaches to human diseases. BR-1 mini pigs were intramuscularly infected with T. gondii with tachyzoites (RH strain) or orally infected with cysts (ME-49 strain). Haematology and serum biochemistry were analysed and buffy coat cells were inoculated in mice to determine tachyzoite circulation. No alterations were observed in erythrocyte and platelet values; however, band neutrophils increased seven days after infection with ME-49. Serology of the mice inoculated with pig blood leucocytes revealed circulating ME-49 or RH strain tachyzoites in the pigs' peripheral blood at two and seven or nine days post-infection. The tachyzoites were also directly observed in blood smears from the infected pigs outside and inside leucocytes for longer periods. Alanine-aminotransferase was high at days 21 and 32 in the RH infected pigs. After 90 days, the pigs were euthanised and their tissue samples were processed and inoculated into mice. The mice serology revealed the presence of parasites in the hearts, ileums and mesenteric lymph nodes of the pigs. Additionally, cysts in the mice were only observed after pig heart tissue inoculation. The infected pigs presented similar human outcomes with relatively low pathogenicity and the BR-1 mini pig model infected with ME-49 is suitable to monitor experimental toxoplasmosis.

Mannitol-induced drought stress on calli of Trigonella foenum-graecum L. Var. RMt-303.

Different explants of fenugreek, T. foenum-graecum L. (Var. RMt-303), were compared for their callus induction and subsequent shoot regeneration capabilities on Murashige and Skoog media supplemented with different phytohormones in varying concentration. The highest percentage of callus induction frequency was observed in 1ppm benzylaminopurine (BAP). Maximum shoots were induced on media supplemented with 0.5ppm BAP using leaf and stem tissues as explants. However, root tissues showed only callusing with no subsequent shooting. Cotyledonary node responded better than hypocotyls in terms of shoot induction on media supplemented with thidiazuron (0.1ppm). The callus was subjected to drought stress as simulated by reduced water potential of growth media due to addition of mannitol. Calli could withstand -2 MPa water potential till 30 days indicating that the drought stress tolerance mechanisms are functional in this variety. Chlorophyll a and b and total chlorophyll, proline and total phenolic contents, total peroxidase and catalase activities increased under stress conditions suggesting the tolerance of callus to drought stress. However, ascorbate peroxidase, guaiacol peroxidase activities were found to decrease slightly. Malondialdehyde and H2O2 contents were found to decrease while only a slight disturbance was found in membrane stability index. These results underline the mechanisms that are crucial for drought stress tolerance in fenugreek.

Nutritional reserves of Vochysiaceae seeds: chemical diversity and potential economic uses

Contents of proteins, carbohydrates and oil of seeds of 57 individuals of Vochysiaceae, involving one species of Callisthene, six of Qualea, one of Salvertia and eight of Vochysia were determined. The main nutritional reserves of Vochysiaceae seeds are proteins (20 percent in average) and oils (21. 6 percent). Mean of carbohydrate contents was 5. 8 percent. Callisthene showed the lowest protein content (16. 9 percent), while Q. cordata was the species with the highest content (30 percent in average). The contents of ethanol soluble carbohydrates were much higher than those of water soluble carbohydrates. Oil contents lay above 20 percent for most species (30. 4 percent in V. pygmaea and V. pyramidalis seeds). The predominant fatty acids are lauric (Q. grandiflora), oleic (Qualea and Salvertia) or acids with longer carbon chains (Salvertia and a group of Vochysia species). The distribution of Vochysiaceae fatty acids suggests for seeds of some species an exploitation as food sources (predominance of oleic acid), for other species an alternative to cocoa butter (high contents or predominance of stearic acid) or the production of lubricants, surfactants, detergents, cosmetics and plastic (predominance of acids with C20 or C22 chains) or biodiesel (predominance of monounsaturated acids). The possibility of exploitation of Vochysiaceae products in a cultivation regimen and in extractive reserves is discussed.

Teores de proteínas, carboidratos solúveis e óleos de sementes de 57 indivíduos de Vochysiaceae, compreendendo uma espécie de Callisthene, seis de Qualea, uma de Salvertia e oito de Vochysia foram determinados. As principais reservas de sementes de Vochysiaceae são proteínas (20 por cento em média) e óleos (21, 6 por cento). A média dos teores de carboidratos foi de 5, 8 por cento. Callisthene apresentou o mais baixo teor de proteínas (16, 9 por cento), enquanto Q. cordata foi a espécie com o mais elevado teor (30 por cento em média). Teores de carboidratos solúveis em etanol foram muito superiores aos solúveis em água. Os teores de óleo foram superiores a 20 por cento na maioria das espécies (30, 4 por cento em V. pygmaea e V. pyramidalis). Ácidos graxos predominantes foram láurico (Q. grandiflora), oleico (Qualea e Salvertia) ou ácidos com cadeias mais longas (Salvertia e um grupo de espécies de Vochysia). A distribuição de ácidos graxos de Vochysiaceae sugere para as sementes de algumas espécies o uso em alimentação (predominância de ácido oléico), para outras, uma alternativa à manteiga de cacau (teores elevadosde ácido esteárico) ou produção de lubrificantes, tensoativos, detergentes, cosméticos e plásticos (predominância de ácidoscom cadeias C20 ou C22) ou biodiesel (predominância de ácidos monoinsaturados). Discute-se a possibilidade de aproveitamento de produtos de Vochysiaceae em regime de cultivo eem reservas extrativas.

Efecto de la variedad y la fertilización en indicadores de calidad proteica in-vitro de dos variedades y una línea de garbanzo (cicer arietinum) / Variety and fertilization effect on indicators of protein quality in-vitro of two varieties and one line of chickpea (cicer arietinum)

Protein quality in relation to the degree of fertilization of two varieties (Costa and Blanco Sinaloa) and an advanced line (Hoga L10) of chickpeas obtained from the Campo Experimental Costa de Hermosillo, Sonora, Mexico from INFAP was evaluated. They were grown in similar conditions with 3 levels of nitrogen fertilization (60,120 and 200K/Ha.). Protein and non-protein nitrogen, digestibility and available lysine were analyzed. Significant differences between the varieties and the advanced line in protein and non-protein nitrogen and available lysine were found. The effect of the degree of fertilization on protein quality was significant, showing that a level ofl20KI Ha an increase is observed in protein and non-protein nitrogen and in the percent of digestibility. No significant differences were observed between 60 and 200KIHa. Available lysine was higher at the 200KIHa level. These indicators of protein quality can be used to complement commercial and agricultural aspects that are evaluated for improvement and selection of new varieties of chickpeas.

En este trabajo se evaluó la calidad proteica in-vitro en dos variedades y una línea avanzada de garbanzo, así como su relación con el grado de fertilización aplicado durante su cultivo. Se utilizaron dos variedades comerciales de garbanzo (Costa y Blanco Sinaloa) y una línea avanzada Hoga L10, sembradas en condiciones ambientales similares, con tres niveles de fertilización de nitrógeno (60, 120 y 200K/Ha.), las cuales fueron obtenidas del Campo Experimental Costa de Hermosillo, Sonora, México del INIFAP. Se llevó a cabo un análisis químico proximal, determinaciones de calidad proteica como: nitrógeno proteico y no proteico utilizando extracciones con ácido tricloroacético, digestibilidad in-vitro por el método multienzimático y lisina disponible. A excepción de digestibilidad in-vitro se observaron diferencias significativas entre las variedades y línea avanzada en: nitrógeno proteico, no proteico y lisina disponible. El efecto de la fertilización fue observado en todos las determinaciones de calidad proteica, los resultados indicaron que al aumentar el nivel de fertilización a 120K/Ha se obtiene un incremento significativo en el porcentaje de nitrógeno proteico y no proteico, así como el porcentaje de digestibilidad. Entre los niveles de 60 y 200K/Ha no se observaron diferencias significativas. La lisina disponible fue mayor en las variedades y líneas con nivel de fertilización de 200K/Ha. Estos indicadores de calidad proteica pueden complementar a los aspectos agronómicos y comerciales que son evaluados en los programas de mejoramiento, en la selección de nuevas variedades de garbanzo para su explotación comercial.

QTL identification of grain protein concentration and its genetic correlation with starch concentration and grain weight using two populations in maize (Zea mays L.).

Protein is one of the three main storage chemical components in maize grains, and is negatively correlated with starch concentration (SC). Our objective was to analyse the influence of genetic backgrounds on QTL detection for protein concentration (PC) and to reveal the molecular genetic associations between PC and both SC and grain weight (GWP). Two hundred and eighty-four (Pop1) and 265 (Pop2) F(2:3) families were developed from two crosses between one high-oil maize inbred GY220 and two normal maize inbreds 8984 and 8622 respectively, and were genotyped with 185 and 173 pairs of SSR markers. PC, SC and GWP were evaluated under two environments. Composite interval mapping (CIM) and multiple interval mapping (MIM) methods were used to detect single-trait QTL for PC, and multiple-trait QTL for PC with both SC and GWP. No common QTL were shared between the two populations for their four and one PC QTL. Common QTL with opposite signs of effects for PC and SCGWP were detected on three marker intervals at bins 6.07-6.08, 8.03 and 8.03-8.04. Multiple-traits QTL mapping showed that tightly-linked QTL, pleiotropic QTL and QTL having effects with opposite directions for PC and SCGWP were all observed in Pop1, while all QTL reflected opposite effects in Pop2.

Efecto de la extrusión sobre la biodisponibilidad de proteína y almidón en mezclas de harinas de maíz y frijol lima / Effect of extrusion on protein and starch bioavailability in corn and lima bean flour blends

La extrusión se emplea para producir expandidos (botanas o snacks), crujientes y quebradizos. El impacto nutricional de este tipo de proceso no ha sido suficientemente estudiado, por ello se evaluó la biodisponibilidad “in vitro” e “in vivo” de la proteína y el almidón en mezclas de harinas de maíz (Zea mays) (M) y de frijol lima (Phaseolus lunatus) (F), tanto crudas como extrudidas. Las mezclas de harinas 75M/25F y 50M/50F (p/p) y fueron procesadas en un extrusor Brabender a 160°C, 100 rpm, y 15,5% de humedad. La composición proximal indicó un aumento del tenor de proteína y cenizas y una disminución de la grasa en los productos extrudidos. La digestibilidad in vitro de la proteína fue mayor en los extrudidos (82%) que en las harinas crudas (77%). Los contenidos de almidón potencialmente disponible y almidón resistente total disminuyeron con la extrusión. Los ensayos in vitro indican que la extrusión mejora la digestibilidad de la proteína y el almidón en las mezclas estudiadas. La biodisponibilidad in vivo se evaluó utilizando gorgojos de arroz (Sithophilus oryzae) como modelo biológico. Los biomarcadores más descriptivos de los cambios sugeridos por las pruebas in vivo fueron: el contenido de proteínas corporales, que incrementó por efecto de la extrusión, y la actividad de la alfa-amilasa intestinal, que disminuyó a consecuencia del procesamiento. Se concluye que la extrusión mejora apreciablemente la calidad nutricional de mezclas de maíz y frijol de lima.

Effect of extrusion on protein and starch bioavailability in corn and lima bean flour blends. Extrusion is used to produce crunchy expanded foods, such as snacks. The nutritional impact of this process has not been studied sufficiently. In this study, in vitro and in vivo protein and starch bioavailability was evaluated in both raw and extruded corn (Zea mays)(C) and lima bean (Phaseolus lunatus)(B) flour blends, prepared in 75C/25B and 50C/ 50B (p/p) proportions. These were processed with a Brabender extruder at 160°C, 100 rpm and 15.5% moisture content. Proximate composition showed that in the extruded products protein and ash contents increased whereas the fat level decreased. In vitro protein digestibility was higher in the extrudates (82%) than in the raw flours (77%). Potentially available starch and resistant starch contents decreased with extrusion. The in vitro assays indicated that extrusion improved protein and starch availability in the studied blends. In vivo bioavailability was evaluated using the rice weevil (Sithophilus oryzae) as a biological model. The most descriptive biomarkers of the changes suggested by the in vivo tests were body protein content (increased by extrusion) and intestinal alpha-amylase activity (decreased by processing). Overall, results suggest that extrusion notably increases the nutritional quality of corn and lima bean flour blends.

Efecto de las prolaminas del grano de maíz (Zea mays L. ) sobre la textura de la tortilla / Effect of the prolamins in maize (Zea mays L. ) grain on tortilla texture

Las prolaminas (zeínas) representan la principal proteína de reserva en el grano de maíz y poco se conoce sobre su participación en la textura de la tortilla. Para determinar su efecto, se evaluaron 6 híbridos de tipo normal y 6 de calidad proteínica (QPM, por sus siglas en inglés). Las variables químicas incluyeron prolaminas, amilosa y almidón. Se determinó la viscosidad de las harinas y la textura de las tortillas en términos de la fuerza de ruptura a tensión y elongación. El contenido de prolaminas en los maíces normales fue 64% más elevado en comparación con los QPMs. No se observó relación entre el contenido de prolaminas y las propiedades de viscosidad de las harinas, como tampoco se halló relación de esta fracción proteínica con la dureza de la tortilla, pero si con la elongación, que mostró una correlación negativa con la cantidad de prolaminas. Las tortillas con mejores características de textura fueron H-161 en maíces normales y H-143C en maíces QPM, ambos maíces presentaron los granos más pequeños dentro de su grupo. Los resultados muestran que un elevado contenido de prolaminas en el grano de maíz podría estar limitando la textura de la tortilla en términos de su elongación.

The prolamins (zeins) are the main storage proteins in the maize grain. There are limited investigations related to their participation on tortilla texture. For determining their effect, normal (6) and Quality Protein Maize (QPM) (6) genotypes were used. The chemical variables comprised prolamins, amylose and starch in whole grain and endosperm. Viscosity of the raw endosperm flour was determined as well as the tortilla texture, expressed in terms of tension force and elongation. Prolamin content in the normal maizes was 64 % higher than that in the QPMs. It was not observed any relationship between prolamin content and flour viscosity. The prolamin content was not related with tortilla hardness, measured as the tension force to rupture the tortilla, but a negative correlation was observed with tortilla elongation. The tortillas with the best texture characteristics were from H-161nomal maize and H-143 QPM maize, both genotypes showed the smallest grain in its respective gruop. According to the results obtained in the present work, a high prolamin content in maize grain could be affecting tortilla elongation.

Fotosíntesis en tres poblaciones altitudinales de la planta andina Espeletia schultzii (Compositae) / Photosynthesis in three altitudinal populations of the Andean plant Espeletia schultzii (Compositae)

Photosynthesis was compared in three altitudinal populations of Espeletia schultzii: 3,100, 3,550 and 4,200 masl. The measured parameters were Rubisco activity (EC 4.1.139), chlorophyll, soluble protein and soluble sugars contents, and specific leaf area (SLA). The 4,200 m population had a higher Rubisco activity (at 4 degrees C) followed by those at 3,550 m and 3,100 m. There were no significant differences between populations at 3,100 m and 3,550 m (ANOVA), but their activities were different from those of the 4,200 m population. Chlorophyll a content decreased slightly with elevation, while chlorophyll b was constant; therefore, the Ra/b ratio decreased with elevation, but not significantly. The leaf soluble sugars content increased along the altitudinal gradient. Leaf protein content did not differ. The SLA decreased with altitude. The increase in Rubisco activity might reflect higher enzyme activation and not higher enzyme protein. The increase in soluble sugars is probably associated to Rubisco activity. Three out of the five measured parameters revealed differences with altitude, suggesting a compromise between a higher metabolic activity and a smaller cellular volume.

Se establece una comparación de algunos parámetros fotosintéticos: actividad Rubisco (Ribulosa 1, 5-bis-fosfato carboxilasa EC 4.1.1.39) contenidos de clorofilas, azúcares solubles totales y proteínas solubles totales y área foliar específica (AFE), en tres poblaciones altitudinales de Espeletia schultzii ubicadas a 3 100, 3 550 y 4 200 msnm. De acuerdo con el análisis de varianza la población a 4 200 m presentó una actividad Rubisco significativamente mayor que las otras dos, en cuyos casos los valores no fueron diferentes. Los contenidos de clorofila a presentan una leve tendencia a la disminución con la altura; mientras que la clorofila b se mantiene constante, razón por la cual la relación a/b (R a/b) disminuye con la elevación, aunque, las diferencias no son significativas. El contenido de azúcares en cada una de las poblaciones estudiadas (gm-2), aumenta con la elevación; las diferencias entre las poblaciones son significativas. Con relación al contenido de proteínas, no existen diferencias entre las poblaciones estudiadas. El área foliar específica (AFE) disminuye significativamente con la altura. Es probable que el incremento en la actividad Rubisco sea producido por una mayor activación de la enzima y no por el mayor contenido de proteína. Los azúcares solubles presentan incremento significativo, este hecho es probable que se encuentre asociado con la actividad Rubisco. De los cinco parámetros fotosintéticos medidos, tres presentan diferencias significativas asociadas con la altitud. Esto representa un compromiso entre una mayor actividad metabólica mantenida en un menor volumen celular.

Morphological variation, histology, histochemistry and nutrient contents of Frankia root nodules in Casuarina equisetifolia.

Root nodules were collected from the existing plantation of Casuarina equisetifolia from three different agroclimatic zones of Tamil Nadu, India. Morphological variation, histology, histochemistry and nutrient contents of the nodules were studied. The nodules were found to be simple, dichotomously branched and coralloid. The stele in simple and branched nodules reached up to the tip of the nodules. Structure of Frankia nodules was described using histochemical methods to elucidate the nature of micro-symbiont within the nodules. The nodule consisted of a distinct periderm enclosing the cortex. The cortex showed patches of infected cells interspersed among the uninfected ones. Inside the cortex was a stele bound by an endodermis, which contained high amount of tannin. The micro-symbiont was observed in the nodule tisues in hyphal form and spore packed sporocorp was also seen in the cortex. The histochemical tests revealed the presence of proteins, insoluble polysaccharides and polyphenols.

Valor nutricional de los alimentos de Tayassu pecari (Artiodactyla: Tayassuidae) en el Parque Nacional Corcovado, Costa Rica / Nutritional values in the diet of white-lipped peccary Tayassu pecari (Artiodactyla: Tayassuidae) in Corcovado National Park, Costa Rica

We determined the potential nutritional levels in 25 species of plants, and in earthworms, that constitute part of the diet of white-lipped peccary (Tayassu pecari) in Corcovado National Park, Costa Rica, from January 1998 to March 1999. The highest content of fat and energy was found in seeds of the Myristicacea family. The highest content of calcium was found in vegetative parts of Dieffenbachia spp. Nutritious contents differed among plant parts (seeds, fruits, stems and leaves). Fat and energy content were larger in seeds and fruits, whereas the largest content of protein was found in fruits and leaves. Mineral content also differed among plant parts. Calcium, potassium and magnesium were higher in leaves whereas copper and zinc were higher in seeds. Differences of diet between white-lipped peccaries in Corcovado and in other tropical regions of Latin America could be partially explained by our results. We found several species with higher fat and energy content than palms, which can explain the low consumption of palm seeds in Corcovado. It is possible that the regular consumption of stems and leaves of some species is related to their high mineral content. Seasonality of reproduction in Corcovado seems to be related not only to fruit availability but also to the nutritional quality of food.

Se determinó el valor nutritivo y mineral de 25 especies vegetales y una especie animal (lombriz de tierra) que forman parte de la dieta del chancho cariblanco (Tayassu pecari) en el Parque Nacional Corcovado, Costa Rica, desde enero de 1998 hasta marzo de 1999. Los mayores contenidos de grasa y energía bruta se encontraron en semillas de la familia Myristicaceae. El mayor contenido de calcio se encontró en partes vegetativas de Dieffenbachia spp. Los contenidos nutritivos fueron diferentes entre las diferentes partes vegetativas analizadas (semillas, frutos, tallos y hojas). El contenido de grasa y energía bruta fue mayor en semillas y frutos, mientras que el mayor contenido de proteina cruda se encontró en frutos y hojas. El contenido de minerales tambien fue diferente entre las partes vegetativas analizadas. Los contenidos de calcio, potasio y magnesio fueron mayores en hojas mientras que los de cobre y zinc fueron mayores en semillas. Diferencias en la dieta de los chanchos cariblancos de Corcovado con los de otras regiones tropicales de Latinoamérica pueden ser parcialmente explicadas con los resultados nutritivos de este estudio. Se encontraron varias especies con mayor contenido de grasa y energía bruta que las palmas, lo que puede explicar el bajo consumo de semillas de palmas en Corcovado. Es posible que el consumo regular de partes vegetativas (hojas y tallos) de algunas especies se deba al alto contenido mineral de estas. La estacionalidad de la reproducción parece estar relacionada no solo a la disponibilidad de alimentos sino tambien a la calidad nutritiva de los mismos.

Nutrient enrichment of cassava peels using a mixed culture of Saccharomyces cerevisae and Lactobacillus spp solid media fermentation techniques

Cassava pulp was fermented with pure strains of Saccharomyces cerevisae and two bacteria namely Lactobacillus delbruckii and Lactobacillus coryneformis for 3 days. The squeezed liquid from the fermented pulp was used to ferment cassava peels for 7 days. Analysis of the dried fermented peels revealed that there was a significant (P < 0.05) increase in the protein content of the cassava peels fermented with squeezed liquid from the inoculated cassava pulp (21.5%) when compared with the unfermented cassava peel (8.2%). Moreover, the treatment equally brought about a significant (P < 0.05) decrease in the cyanide (6.2 mg/kg) and phytate content (789.7 mg/100g) when compared with the unfermented cassava peels, which had 44.6 mg/kg cyanide and 1043.6 mg/100g phytate. The fermented cassava peels could be a good protein source in livestock feeds.

Efecto de la extrusión sobre la actividad de factores antinutricionales y digestibilidad in vitro de proteínas y almidón en harinas de Canavalia ensiformis / Effect of extrusion on the activity of anti-nutritional factors and in vitro digestibility of protein and starch in flours of Canavalia ensiformis

The effect of the extrusion (155 degrees C, 20 per cent moisture, screw speed 75 rpm, feed speed 205 g min-1) on antinutritional factors of Canavalia ensiformis was studied. In vitro protein and starch digestibilities were assessed. The extrusion not affect protein content (23 per cent) in the flours, but significantly (P < 0.01) decrease moisture content. The protein digestibility values were improved from 57.5 to 89.5 per cent, these values were lower than casein (98.19 per cent). The digestibility of starch values were improved from 37.7 to 53 per cent. The protease inhibitors activities (trypsin and chymotrypsin) and alpha-amylase inhibitor activity were reduced by 95 per cent. The haemagglutinating activity was eliminated as result of the high temperature employed during the extrusion process. The canavanine content in the flours were not affect by the treatment of extrusion.

Ebony (Phitecellobium flexicaule Benth) and proteins fractionation, solubilization, characterization and production of an isolate

Different combinations of pHs (2 to 12) and temperatures (25, 30 and 35 degrees C) were tested to obtain a protein isolate from ebony (Pithecellobium flexicaule, Benth) seeds. Seed proteins contained 54.6 per cent albumins, 32 per cent globulins, 5.7 per cent glutelins and 1.3 per cent prolamins. The isoelectric points for albumins, globulins and glutelins were in the pH range of 2.3-2.7. The average molecular weight of albumins ranged from 92 to 100 kDa and for the four globulin subunits in the range of 28.4 to 57.3 kDa. For isolate production, proteins were sequentially extracted with distilled water and a 5 per cent NaCl solution. The resulting supernatants were mixed. The best extraction was achieved at pH 11 and 25 degrees C. 45.6 per cent of the total seed protein was precipitated at pH 2.6 yielding an isolate with 90 per cent protein (N x 6.25). The isolate contained high quantities of lysine, leucine, threonine and phenylalanine but were low in sulfur containing amino acids methionine and cysteine. The extraction process reduced tannins, phytates and trypsin inhibitor in 53, 70 and 70 per cent, respectively. In vivo protein digestibility of the protein isolate was 85.4 per cent and the corrected digestibility essential amino acid score was of 44 per cent due to the lack of sulfur containing amino acids. In order to upgrade the protein quality of ebony isolate it is recommend to supplement with methionine or sulfur containing rich foods.