Efecto de la cáscara o pulpa de Solanum Tuberosum sobre el peso de órganos y estrés oxidativo hepático en ratas obesas / Effect of Solanum Tuberosum peel or pulp on organ weight and hepatic oxidative stress in obese rats

RESUMEN Con el objetivo de determinar el efecto del consumo de harina de cáscara o harina de pulpa de dos variedades de Solanum tuberosum (papa Yungay y papa Canchán) sobre la acumulación de tejido adiposo, peso de órganos y estrés oxidativo en hígado de ratas realizamos un estudio experimental en 24 ratas Holtzman obesas, divididos en cuatro grupos y, sometidas a dietas que contenían 10% de harina de las dos variedades de papa. Los grupos fueron T1: cáscara Yungay, T2: pulpa Yungay; T3: cáscara Canchán; y T4: pulpa Canchán. Al finalizar, se sacrificaron todos los animales para registrar los pesos de órganos y tejido adiposo, y extraer muestras para determinar la actividad enzimática de superóxido dismutasa y catalasa en el hígado. El grupo de ratas obesas que consumió pulpa de variedad Yungay tuvo menor estrés oxidativo en el hígado; además, independientemente de la parte de tubérculo consumido, esta variedad redujo el peso de los riñones.

ABSTRACT This study aimed to determine the effect of the consumption of peel flour or pulp flour from two varieties of Solanum tuberosum (Yungay potato and Canchán potato) on the accumulation of adipose tissue, organ weight, and oxidative stress in the liver of rats. We carried out an experimental study in 24 obese Holtzman rats, divided into four groups and subjected to diets containing 10% flour from both varieties of potato. The groups were T1: Yungay peel; T2: Yungay pulp; T3: Canchán peel; and T4: Canchán pulp. When the study was completed, all the animals were slaughtered to record the weights of organs and adipose tissue and to extract samples to determine the enzyme activity of superoxide dismutase and catalase in the liver. The group of obese rats that consumed the pulp of the Yungay variety had less oxidative stress in the liver. Also, regardless of the tuber part consumed, this variety reduced the weight of the kidneys.

Papas nativas con potencial antioxidante, cultivadas en el norte del Perú / Native potatoes with antioxidant potential, grown in northern Peru

Peru is not only megadiverse in flora and fauna, but also in "native varieties of potatoes" that have been used by pre-Inca civilizations. In this context, "native potatoes" not only have a high nutritional value in antioxidants, but also a high capacity to cure and/or alleviate diseases; providing quality of life that is reflected in the longevity of the Andean population. However, in the absence of documentation and dissemination, many varieties and their ethnobotanical knowledge is being lost. To preserve and disseminate this valuable ancestral knowledge, a taxonomic, phytogeographic and ethnobotanical inventory was carried out, based on periodic botanical explorations during the period 1997-2017. The information obtained was complemented with other researches and reports by other authors. 317 "varieties of native potato" are reported for the North of Peru, of which 86, are "native varieties of colored pulp".

El Perú no sólo es megadiverso en flora y fauna, sino también en "variedades nativas de papas" que han sido utilizadas desde las civilizaciones preincas. En este contexto las "papas nativas" no sólo poseen un elevado valor nutricional en antioxidantes, sino también una alta capacidad de curar y/o aliviar enfermedades; brindando calidad de vida que se refleja en la longevidad de la población andina. Sin embargo, ante la falta de documentación y difusión, muchas variedades y su conocimiento etnobotánico se está perdiendo. Para preservar y difundir este valioso conocimiento ancestral, se llevó a cabo un inventario taxonómico, fitogeográfico y etnobotánico, en base a exploraciones botánicas periódicas durante el período 1997-2017. La información obtenida se complementó con otras investigaciones y reportes de otros autores. Se reportan para el Norte del Perú 317 "variedades de papa nativa", de las cuales 86, son variedades "nativas de pulpa de color".

Avaliação do teor de sódio contido em salgadinhos industrializados comercializados em supermercados / Evaluation of the sodium content contained in industrialized salted snacks marketed in supermarkets

Objetivo: Analisar experimentalmente o teor de sódio de sal-gadinhos industrializados disponíveis no comércio da Cidade de Maceió, Alagoas. Material e Métodos: Classificar o teor de sódio de acordo com a legislação vigente. Vinte amostras de salgadinho de milho, trigo e batata, de diferentes sabores foram avaliadas utilizando-se a metodologia de espectrofotometria de emissão com atomização em chama. Resultados: Verificou-se que todas as amostras apresentavam a classificação de "alto teor" de sódio, tendo por base a RDC n° 24 de 2010 da Anvisa e que 65% das amostras apresentaram valores reais do teor de sódio superiores aos que estavam declarados nos rótulos. Conclusão: Com relação ao teor de sódio encontrado nos salgadinhos analisados, verificou-se que todas as amostras apresentaram a classificação de "alto teor" de sódio. (AU)

Objective:The objective of the study was to analyze experi-mentally the sodium content of commercially available savory foods in the city of Maceió, Alagoas,. Method: to classify this content according to the current legislation. Twenty samples of corn flakes, wheat and potato snacks of random flavors were evaluated using the emission spectrophotometry with in-line flame atomization method. Results: It was verified that all The samples presented a sodium "high content" classification, based on Anvisa's RDC nº 24 of 2010 and that it was also observed that 65% of the samples had actual values of sodium content higher than those declared on the labels. Conclusion: Regarding the sodium content found in the analyzed snack foods, it was found that all samples had the classification of "high" sodium. (AU)

Terapia electroquímica: relación del patrón espacial del daño tisular con la forma del arreglo de electrodos / Electrochemical therapy: relationship of the tissular damage space pattern with the form of electrodes repair

Se realizó una investigación en la Escuela Superior de Ingeniería Mecánica y Eléctrica del Instituto Politécnico Nacional de Ciudad de México, desde mayo hasta junio de 2016, con el objetivo de determinar cómo cambia el patrón espacial del daño tisular con la forma del arreglo de electrodos en piezas tridimensionales de papa (Solanum tuberosum L) bajo la acción de 10 mA durante 30 min para los arreglos de electrodos con formas colineal, circular, elíptica, parabólica e hiperbólica). Los resultados mostraron la estrecha relación entre el daño tisular y la forma del arreglo de electrodos, así como algunos hallazgos que se observan también en tumores, tales como: necrosis circular alrededor de todos los electrodos, daño tisular extensivo en espacio y en tiempo, burbujeo alrededor del cátodo, zona blanca alrededor del ánodo; igualmente, se observó que las regiones alejadas de los electrodos no se afectaron

An investigation in the Mechanical and Electric Engineering Higher School of the National Polytechnic Institute of Mexico City, was carried out from May to June, 2016, aimed at determining how the tissue damage space pattern changes with the electrodes position form in three-dimensional pieces of potato (Solanum tuberosum L) under the 10 MA action during 30 minutes for electrodes position with cholineal, round, elliptic, parabolic and hyperbolic forms). The results showed a close relationship between the tissue damage and the electrodes position form, as well as some findings that are also observed in tumors, such as: circular necrosis around all the electrodes, extensive tissue damage in space and time, bubbling around the cathode, white area near the anode; likewise, it was observed that the regions far from the electrodes were not affected

Efficient production of pullulan by Aureobasidium pullulans grown on mixtures of potato starch hydrolysate and sucrose

Abstract Pullulan is a natural exopolysaccharide with many useful characteristics. However, pullulan is more costly than other exopolysaccharides, which limits its effective application. The purpose of this study was to adopt a novel mixed-sugar strategy for maximizing pullulan production, mainly using potato starch hydrolysate as a low-cost substrate for liquid-state fermentation by Aureobasidium pullulans. Based on fermentation kinetics evaluation of pullulan production by A. pullulans 201253, the pullulan production rate of A. pullulans with mixtures of potato starch hydrolysate and sucrose (potato starch hydrolysate:sucrose = 80:20) was 0.212 h−1, which was significantly higher than those of potato starch hydrolysate alone (0.146 h−1) and mixtures of potato starch hydrolysate, glucose, and fructose (potato starch hydrolysate:glucose:fructose = 80:10:10, 0.166 h−1) with 100 g L−1 total carbon source. The results suggest that mixtures of potato starch hydrolysate and sucrose could promote pullulan synthesis and possibly that a small amount of sucrose stimulated the enzyme responsible for pullulan synthesis and promoted effective potato starch hydrolysate conversion effectively. Thus, mixed sugars in potato starch hydrolysate and sucrose fermentation might be a promising alternative for the economical production of pullulan.

Efecto del extracto acuoso de la papa nativa Solanum tuberosum "puca simi" sobre enzimas de detoxificación de fase II en un modelo de hiperbilirrubinemia / Effect of the aqueous extract of the native potato Solanum tuberosum "puca simi" on phase II detoxification enzymes in a model of hyperbilirubinemia

El objetivo del presente estudio fue evaluar el efecto del extracto acuoso de la papa nativa Solanum tuberosum "puca simi" sobre enzimas de detoxificación de fase II en un modelo de hiperbilirrubinemia. Se empleó 28 ratas de cepa Rattus norvegicus de 200 a 250 g de peso en cuatro grupos de siete cada uno, a los que se le administró el siguiente tratamiento por vía orogastrica: Grupo I Control, suero fisiológico; Grupo II, Fenilhidrazina 60 mg/kg de peso; Grupo III, extracto de papa 665 mg/kg de peso; Grupo IV, Extracto de papa y Fenilhidrazina. Se determinó los niveles de proteínas totales, bilirrubina total, malondialdehido (MDA), hematocrito y la actividad de glutatión S-transferasa (GST), UDP-glucuroniltransferasa. En el estudio fitoquímico de encontró polifenoles, flavonoides y saponinas, se halló una disminución significativa (p<0,05) de los niveles de hematocrito, bilirrubina total en los grupos III y IV respecto a los grupos I y II. También se encontró una disminución significativa (p<0,05) de la lipoperoxidación en el grupo III (1,53 ng/g tej) y IV (1,56 ng/g tej) respecto al grupo II (2,03 ng/g tej) y grupo I (1,63 ng/g tej), asimismo la actividad específica de la UDP-glucuroniltransferasa aumentó significativamente (p<0,01) en el grupo IV con respecto a los demás grupos, pero la actividad específica y total de la glutatión S-transferasa no exhibe ninguna diferencia ignificativa en los cuatro grupos, incrementa de manera significativa el efecto del GSH total en los grupos III y IV respecto a los grupos I y II (p<0,05). Se concluye que el extracto de papa nativa "puca simi" contiene metabolitos secundarios que protegen la lipoperoxidación e incrementa de manera significativa la actividad de la UDP glucuroniltransferasa, enzima de detoxificación de fase II.

Profiling carbohydrate composition, biohydrogen capacity, and disease resistance in potato

Background: Potato (Solanum tuberosum) is one of the most important sources of carbohydrates in human diet. Because of its high carbohydrate levels it recently has also received attention in biohydrogen production. To exploit the natural variation of potato with respect to resistance to major diseases, carbohydrate levels and composition, and capacity for biohydrogen production we analyzed tubers of native, improved, and genetically modified potatoes, and two other tuberous species for their glucose, fructose, sucrose, and starch content. Results: High-starch potato varieties were evaluated for their potential for Caldicellulosiruptor saccharolyticus-mediated biohydrogen production with Desirée and Rosita varieties delivering the highest biohydrogen amounts. Native line Vega1 and improved line Yagana were both immune to two isolates (A291, A287) of Phytophthora infestans. Conclusions: Our data demonstrate that native potato varieties might have great potential for further improving the multifaceted use of potato in worldwide food and biohydrogen production.

Pilot screening of acrylamide level in some Egyptian brands of potato aaaand corn products

Acrylamide is a chemical compound produced in starchy foods that have been cooked at high temperatures. Acrylamide is proven to be carcinogenic in rodents and a probable human carcinogen, with increasing evidence of positive associations with human cancers. Acrylamide is formed in potato crisps, chips, bread and crisp bread. lt was first discovered by scientists in Sweden in 2002. To determine the level of acrylamide in popular Egyptian brands of potato crisps and corn products produced by domestic food industrial factories. Seven brands of potato and eight brands of corn products were collected, crashed and after preparing the extracts of each sample, high performance liquid chromatography [HPLC] was used for measuring the amount of acrylamide. The amounts of acrylamide ranged 247-1677 micro g/kg in potato brands and <35-419 micro g/kg in corn products. As acrylamide is a dangerous toxin for human health, its level in these products, that are used extensively by people especially children, should be strictly traced and reduced

Organogénesis directa in vitro a partir de hojas de la planta antiplasmodial solanum nudum dunal / Direct organogenesis in vitro from leaves of solanum nudum dunal – antiplasmodial plant

Solanum nudum Dunal (Solanaceae), es una especie vegetal con potencial para desarrollar un tratamiento quimioterapéutico contra la malaria. Este es el primer reporte de un protocolo rápido, eficiente y reproducible de organogénesis directa a partir de segmentos de hoja de plántulas in vitro de esta especie.Los segmentos de hojas de plántulas de 5 meses de germinadas fueron cultivados sobre medio Murashige y Skoog (MS) a mitad de sales y vitaminas, con diferentes concentraciones de Bencilaminopurina (BAP), en combinación con Acido Indolacético (AIA). Se evaluó también el efecto de la iluminación en periodos 0/45, 15/30 y 30/15 días oscuridad/ luz, sobre la inducción de brotes. Se registró un promedio alto de formación de brotes (4,83) en explantes cultivados en medio suplementado con 2,0 mg/L de BAP y 0,1 mg/L de AIA, bajo condición de iluminación por un periodo de 30/15 días oscuridad/luz. Luego de la inducción, los brotes obtenidos fueron transferidos a medio MS suplementado con 0,3 mg/L de Giberelina (GA3), y mantenidos en condiciones de luz donde también enraizaron. Las plántulas regeneradas se llevaron a condiciones de invernadero y fueron morfológicamente similares a las plantas madres.

Solanum nudum Dunal (Solanaceae) is a plant with a potential for developing chemotherapeutic treatments against malaria. This is the first report of a fast, efficient, and reproducible direct organogenesis protocol from leave segments from in vitro seed-grown plantlets.Leaves segments from 5 months old germinated plantlets were placed on half concentration Murashige and Skoog medium (MS), supplemented with several concentrations of Bencilaminopurin (BAP) combinated with Indolacetic Acid (IAA). Dark/ light incubation effect in periods 0/45, 15/30 and 30/15 dark/light days were evaluated on the buds induction. High frequency buds formation was shown (4,83) in explants cultured on MS supplemented with BAP 2,0 mg/L and AIA 0,1 mg/L under a period of 30 days of dark condition incubation. After induction, buds obtained were transferred to MS medium supplemented with gibberellic acid (GA3) 0,3 mg/L and maintained under artificial cool light, there the plantlets rooted. Regenerated plantlets were placed under greenhouse conditions and these were morphologically similar to donor plants.

Estudo da influência da área específica nas alterações do óleo de soja utilizado em frituras descontínuas com batata inglesa / Study of the influence of the specific area in the alterations of the oil of soy used in frying with potato

Para verificar as possíveis influências de áreas específicas no óleo de soja refinado utilizado em frituras descontínuas com batata inglesa, conduziu-se o experimento, viariando-se as áreas específicas de três fritadeiras, F1, F2 e F3, as quais inicialmente foram de 0,11; 0,17 e 0,23 (cm² mL), respectivamente. A temperatura e o tempo de aquecimento utilizados foram de 190 + 10° C por 36 horas. Em cada fritadeira foram realizadas duas frituras diárias com batata inglesa. As alterações ocorridas no óleo de soja durante o processo de frituras diárias com batata inglesa. As alterações ocorridas no óleo de soja durante o processo de fritura foram monitoradas nos tempos 0; 12; 24 e 36 horas de aquecimento, através das principais determinações, que caracterizam a identidade e a qualidade dos óleos comestíveis. As características de identidade foram avaliadas pelas determinações da composição em ácidos graxos e dos índices de iodo e de refração; as de qualidade através da acidez, dienos e conjugados, índice de peróxido, cor e compostos polares e apolares. Os resultados das determinações utilizadas para avaliar as características de identidade e qualidade no óleo original, mostraram que o mesmo se encontrava dentro dos padrõe exigidos pela legislação brasileira (M.S./ANVISA, 1999) e pelo Codex Alimentarius (CODEX / FAO / WHO, 1989).

Teores de ácidos graxos trans de alguns alimentos consumidos no Rio de Janeiro / Trans fatty acids of some foods consumed in Rio de Janeiro, Brazil

Desconhecem-se os teores de ácidos graxos trans em diversos alimentos. Este estudo analisou os teores de ácidos graxos trans, saturados, monoinsaturados e poliinsaturados em batatas fritas, biscoitos e sorvetes. As batatas fritas foram dos tipos chips e de duas redes de fast food, os sorvetes, de duas marcas comerciais e de duas lojas de fast food, e os biscoitos, de marcas diferentes. As amostras de batatas chips e de biscoitos pertenciam a lotes distintos e foram adquiridas em supermercados da região. Analisaram-se seis amostras por produto, através de cromatografia gasosa. O valor médio dos ácidos trans de batatas fritas de redes de fast food foi de 4,74g/100g, enquanto em batatas chips estes ácidos graxos não foram detectados. Nos sorvetes os valores variaram de 0,041g a 1,41g e em biscoitos, de 2,81g a 5,60g. Biscoitos tipo cream cracker apresentaram teores de ácidos graxos trans mais altos e de insaturados mais baixos. Concluiu-se que alguns produtos apresentaram, em 100g, teores de ácidos graxos trans superiores aos recomendados para ingestão total diária em diversos países.

Important amino acid residues of potato plant uncoupling protein (StUCP)

Chemical modifications were used to identify some of the functionally important amino acid residues of the potato plant uncoupling protein (StUCP). The proton-dependent swelling of potato mitochondria in K+-acetate in the presence of linoleic acid and valinomycin was inhibited by mersalyl (Ki = 5 æM) and other hydrophilic SH reagents such as Thiolyte MB, iodoacetate and 5,5'-dithio-bis-(2-nitrobenzoate), but not by hydrophobic N-ethylmaleimide. This pattern of inhibition by SH reagents was similar to that of brown adipose tissue uncoupling protein (UCP1). As with UCP1, the arginine reagent 2,3-butadione, but not N-ethylmaleimide or other hydrophobic SH reagents, prevented the inhibition of StUCP-mediated transport by ATP in isolated potato mitochondria or with reconstituted StUCP. The results indicate that the most reactive amino acid residues in UCP1 and StUCP are similar, with the exception of N-ethylmaleimide-reactive cysteines in the purine nucleotide-binding site

Studies on ATP-diphosphohydrolase nucleotide-binding sites by intrinsic fluorescence

Potato apyrase, a soluble ATP-diphosphohydrolase, was purified to homogeneity from several clonal varieties of Solanum tuberosum. Depending on the source of the enzyme, differences in kinetic and physicochemical properties have been described, which cannot be explained by the amino acid residues present in the active site. In order to understand the different kinetic behavior of the Pimpernel (ATPase/ADPase = 10) and Desirée (ATPase/ADPase = 1) isoenzymes, the nucleotide-binding site of these apyrases was explored using the intrinsic fluorescence of tryptophan. The intrinsic fluorescence of the two apyrases was slightly different. The maximum emission wavelengths of the Desirée and Pimpernel enzymes were 336 and 340 nm, respectively, suggesting small differences in the microenvironment of Trp residues. The Pimpernel enzyme emitted more fluorescence than the Desirée apyrase at the same concentration although both enzymes have the same number of Trp residues. The binding of the nonhydrolyzable substrate analogs decreased the fluorescence emission of both apyrases, indicating the presence of conformational changes in the neighborhood of Trp residues. Experiments with quenchers of different polarities, such as acrylamide, Cs+ and I- indicated the existence of differences in the nucleotide-binding site, as further shown by quenching experiments in the presence of nonhydrolyzable substrate analogs. Differences in the nucleotide-binding site may explain, at least in part, the kinetic differences of the Pimpernel and Desirée isoapyrases.

Resolution of mitochondrial and chloroplast membrane protein complexes from green leaves of potato on blue-native polyacrylamide gels.

Purification of mitochondria and mitochondrial protein complexes from green tissues is often severely impaired by the presence of chloroplasts and their proteins. Here we present a method which allows analysis of respiratory protein complexes from potato leaves. The procedure includes the preparation of an organellar fraction specifically enriched in mitochondria and the separation of organellar protein complexes by blue-native polyacrylamide gel electrophoresis (BN-PAGE). For the first time mitochondrial and chloroplast protein complexes have been resolved simultaneously in a native gel. BN-PAGE allowed the separation of eleven bands, including the mitochondrial NADH-dehydrogenase, the bc1 complex and the mitochondrial F1-ATP synthase as well as the chloroplast F1-ATP synthase, the cytochrome b6f complex, the two photosystems and the light harvesting complex. The resolution of the protein complexes in the first dimension was good enough to allow identification of all subunits of individual complexes in the second dimension under denaturing conditions. Thus, BN-PAGE offers an opportunity to analyze mitochondrial and chloroplast protein complexes from a single preparation from very small amounts of tissue. The implications of our findings, for studies on protein expression and turnover in different tissues and developmental stages, are discussed.

Teor de açúcar em genótipos de batata (Solanum tuberosum L.) / Sugar content in potato (Solanum tuberosum L.) genotypes

O objetivo deste trabalho foi avaliar o teor de açúcares redutores e totais, em tubérculos de batata de germoplasma selecionado do programa de melhoramento da Embrapa Clima Temperado. Dezoito cultivares e clones, e duas cultivares de indústria (Atlantic e Bintje, testemunhas) foram avaliadas neste estudo. O experimento foi conduzido no outono de 1994, em Pelotas, RS. A concentraçäo de açúcares redutores nos tubérculos dos 20 genótipos variou de 0,21 porcento a 1,71 porcento. O clone C-1582-25-90 e a cultivar Cerrito Alegre apresentaram teores mais baixos de açúcares redutores do que as testemunhas, sem, no entanto, diferirem significativamente destas. Os outros clones e cultivares testados também näo diferiram da Atlantic. Estes resultados indicam que no germoplasma da Embrapa Clima Temperado existem genótipos com teor de açúcares redutores semelhante ao dos genótipos utilizados pelas indústrias brasileiras de processamento de batata. Entretanto, nenhum deles apresenta baixo teor de açúcares redutores. A concentraçäo de açúcares totais foi mais baixa nos tubérculos das cultivares Cristal e Macaca, e do clone C-1572-25-90, sem diferir significativamente das testemunhas.

Properties of starch recovered from effuent of snack factories

Snack factories produce effluents, which are high in starch and suspended solids. The recovery of starch from effluent shows, besides a significant improvement of the effluent quality, a very promising substrate. Analysis for chemical composition, microscopic examination, colour measurements and viscosity of recovered starch paste were carried out. The result of analysis revealed that, the recovered starch met the Egyptian standards for edible starch. The colour quality was promising and just needs little purification. Recovered potato starch has several interesting, desirable characteristics. These include swelling power that results in high viscosity of the pastes. The excellent colloidal properties of recovered starch suggest a high spreading industrial potentiality in the near future for local market. Microscopic examination supported some of these findings

Determinaçäo de resíduos de carbofuran em vegetais por cromatografia líquida de alta eficiência (HPLC) / Carbofuran residues determination in vegetables by high efficiency liquid chromatography (HPLC)

O pesticida carbofuran (2,3-dihydro-2,2-dimethyl-7-benzo-furanyl-N-methylcarbamate) é um inseticida-nematicida de amplo espectro de aplicaçao, sendo empregado em escala crescente em muitos países tropicais, devido a sua eficácia contra numerosos insetos e pestes de frutas, vegetais e graos. Apresenta natureza polar e aromaticidade que tornam a determinaçao por HPLC com detecçao no UV atrativa. A análise foi efetuada em cromatógrafo Shimadzu com detector espectrofotométrico ajustado em 275 nm. Na separaçao foi empregada uma coluna Nucleosil C-18 (250 x 4 mm, 5 mum) e metanol-água (50:50, v/v; l mL/min). O volume injetado foi de 20 muL. A eficiência do procedimento foi investigada com amostras de tomate e batata fortificadas com carbofuran em O,1 e 1,0 mg/kg. As amostras foram trituradas em metanol. Após procedeu-se extraçao líquido-líquido com diclorometano. Para remover coextrativos ácidos foi empregada lavagem com hidróxido de sódio diluído. As recuperaçoes variaram entre 94,7 e 98,3 por cento para tomate e entre 95,3 e 97,2 por cento para batata. O limite de detecçao de O,14 mg/L corresponde a concentraçao mínima detectável de O,01l mg/kg em vegetais após a extraçao de 25 g de amostra. Estes resultados indicam o grande potencial do método descrito na determinaçao de resíduos de carbofuran nos vegetais estudados.

Arsénico en tubérculos de papa de las zonas de Junín (Valle de Mantaro) y Lima / Arsenic

Se ha cuantificado arsénico por el método espectrofotométrico de Vasac y Sedivec en tubérculos de papas de cultivos expuestos. Las muestras proceden del Valle del Mantaro (Junín) y de las zonas de Cañete, Barranca, Puente Piedra y Huachipa (Lima). La investigación se realizó en 50 tubérculos de diferentes variedades y formas de riego. El nivel medio de Arsénico en las muetras fue de 0,2572 ppm ñ 0,0132, con una desviación standard de 0,0927ñ0,0093 y cifras extremas de 0,095-0.500 ppm. Los valores promedios obtenidos de arsenico en los tubérculos es menos que los valores máximos aceptables de Canadá ya que solo constituyen el 25,72 por ciento de 1ppn, que es la cantidad máxima de arsénico aceptada en la papa, ya que a partir de ella produce efectos nocivos y tóxicos.

Prevençäo do escurecimento em batatas frescas descascadas e fatiadas / Prevention of browning in fresh sliced peeled potatoes

Foram examinados métodos alternativos para prevençäo do escurecimento em batatas frescas fatiadas, sem emprego de agentes dulfitantes. A inativaçäo de enzimas pelo calor, o emprego de agentes redutores, agentes quelantes e reduçäo do teor de oxigênio na embalagem foram os meios utilizados, isoladamente ou em associaçäo, para evitar o desencadeamento das reaçöes enzimáticas. Os resultados evidenciaram que o pré-tratamento da batata fatiada, por imersäo em soluçäo contendo 0,3 por cento de ácido cítrico e 0,3 por cento de ácido ascórbico, associado a uma embalagem com baixa permeabilidade ao oxigênio, permite conservar o produto sem escurecimento e com boa textura por um período de 17 dias, sob refrigeraçäo. O controle do desenvolvimento de microrganismos foi satisfatório, durante o armazenamento, com a adiçäo de 0,2 por cento de sorbato de potássio à soluçäo de imersäo

Contenido de fibra dietética y digestibilidad del nitrógeno en alimentos centroamericanos: Guatemala / Dietary fiber content and nitrogen digestibility in Central American foods: Guatemala

El presente estudio informa sobre el contenido de fibra dietética en cuatro grupos de alimentos de la América Central: cereales y productos; frijol crudo y procesado; verduras crudas y procesadas y alimentos farináceos, como la papa, yuca y plátano. Además de proporcionar información sobre fibra soluble e insoluble, se dan a conocer datos sobre digestibilidad de la proteína in vitro. El contenido de fibra dietética total de los productos de harina de trigo varió de 1.62 a 2.83% en base fresca, con la excepción del pan integral que mostró un contenido de 7.57%. La tortilla de maíz acusó valore de 3.96 a 5.21% respecto a los frijoles, y los valores de frijol cocido y colorado fluctuaron entre 6.36 y 7.00% independientemente del color; sin embargo, el frijol refrito mostró valores de 15.28 a 17.58%. Las verduras contienen cantidades de fibra dietética total, de 1.51 a 4.34%, y tubérculos, entre 1.31 y 2.86%