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Taro corms contain valuable bioactive molecules effective against cancer and cancer-related risk factors, such as carcinogens and biological agents, several pathophysiological conditions, including oxidative stress and inflammation, while controlling metabolic dysfunctions and boosting the immunological response. Such broad effects are achieved by the taro health-influencing compounds displaying antitumoral, antimutagenic, immunomodulatory, anti-inflammatory, antioxidant, anti-hyperglycemic, and anti-hyperlipidemic activities. Taro bioactivities are attributed to the combination of tarin, taro-4-I polysaccharide, taro polysaccharides 1 and 2 (TPS-1 and TPS-2), A-1/B-2 α-amylase inhibitors, monogalactosyldiacylglycerols (MGDGs), digalactosyldiacylglycerols (DGDGs), polyphenols, and nonphenolic antioxidants. Most of these compounds have been purified and successfully challenged in vitro and in vivo, proving their involvement in the aforementioned activities. Although these health-promoting effects have been recognized since ancient times, as well as other valuable features of taro for food profit, such as hypo-allergenicity, gluten-free, and carbohydrates with medium-glycemic index, taro crop remains underexploited. The popularization of taro intake should be considered a dietary intervention strategy to be applied to improve the overall health status of the organism and as supportive therapy to manage tumorigenesis.

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Throughout evolution, plants have developed the ability to produce secondary phenolic metabolites, which are important for their interactions with the environment, reproductive strategies and defense mechanisms. These (poly)phenolic compounds are a heterogeneous group of natural antioxidants found in vegetables, cereals and leguminous that exert beneficial and protective actions on human health, playing roles such as enzymatic reaction inhibitors and cofactors, toxic chemicals scavengers and biochemical reaction substrates, increasing the absorption of essential nutrients and selectively inhibiting deleterious intestinal bacteria. Polyphenols present in some commodity grains, such as soy and cocoa beans, as well as in other vegetables considered security foods for developing countries, including cassava, taro and beetroot, all of them cropped in Brazil, have been identified and quantified in order to point out their bioavailability and the adequate dietary intake to promote health. The effects of the flavonoid and non-flavonoid compounds present in these vegetables, their metabolism and their effects on preventing chronic and degenerative disorders like cancers, diabetes, osteoporosis, cardiovascular and neurological diseases are herein discussed based on recent epidemiological studies.

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O objetivo desta pesquisa foi comparar as propriedades do amido nativo de taro (Colocasia esculenta L. Schott), clone Macaquinho, com o seu amido modificado por oxidação para utilização pela indústria alimentícia. As amostras foram avaliadas com base nas alterações referentes à sua morfologia e propriedades funcionais. Os percentuais de grupos carboxila e carbonila obtidos após modificação classificou o tratamento empregado como brando, o qual é determinante para a caracterização funcional desse amido. A microscopia revelou grânulos com formatos circulares e poliédricos, aglomerados, tendo o amido oxidado apresentado grânulos um pouco mais volumosos. O amido oxidado mostrou maior poder de intumescimento e solubilidade na temperatura prevista para gelatinização (75ºC), embora tenha sido superado pelo homólogo nativo em temperatura próxima a 80ºC, com valores máximos para ambos os amidos a 95ºC. O amido oxidado também apresentou maior capacidade de absorção de água e óleo, transparência e propriedades de pasta em relação ao amido nativo. A modificação conduzida evidenciou excelentes vantagens para a indústria alimentícia que necessita de produtos com propriedades específicas em temperaturas mais baixas em virtude da rapidez desejada no preparo de sopas, molhos e sobremesas, entre outros alimentos instantâneos.

The objective of this study was to compare the properties of native starch from taro (Colocasia esculenta L. Schott), clone "Macaquinho" with its starch modified by oxidation to be utilized in the food industry. The samples were evaluated based on the alterations of morphology and functional properties. The percentage of carbonyl and carboxyl groups obtained after modifi cation, classify the applied treatment as mild, and that is a determiningfactor for the functional characterization of starch. Microscopy revealed beads with circular and polyhedral, clusters, where the oxidized starch granules showed a little more bulky. The oxidized starch obtained the highest swelling power and solubility due to gelatinization temperature (75°C), although it has been overcome by the native starch at a temperature close to 80°C, with maximum values for both starches at 95°C. The oxidized starch presented better capability of absorbing water and oils, transparency and paste properties in comparison with native starch. The performed modifi cation presents great advantages for the food industry that needs more products with specifi c properties at lower temperatures, due to the speed required to prepare products such as soups, sauces, desserts, and other instant foods.

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Se determinó el efecto depresivo sobre plantas de malanga producidas in vitro del cultivar “Amarilla Especial”, de los hongos Fusarium oxysporum Schlecht, Rhizoctonia solani Kühn y Sclerotium rolfsii Sacc aislados de plantas infectadas que presentaban síntomas de escaso desarrollo, clorosis, necrosis foliar y pudrición de las raíces. Los tratamientos consistieron en el aislamiento de los tres hongos por separado, la mezcla de los tres hongos y un control sin inocular. Se plantaron plantas previamente aclimatizadas en cámaras que tenían una dimensión de 0,90 x 0,90 x 0,90 m, en bloque completamente al azar con cuatro réplicas. Se inocularon 100 plantas por cada tratamiento y como control se dejaron igual número de plantas sin inocular, se evaluó en cada caso la altura de la planta, el número de raíces por planta y el número de raíces enfermas, y posteriormente se determinó el peso fresco y seco de las raíces y el follaje. Se cosechó a los 10 meses después de la plantación y se evaluaron algunos componentes del rendimiento, como el número de cormos y cormelos y su peso fresco, al igual que la intensidad de los daños en el momento de la cosecha. Los resultados mostraron que los hongos fitopatógenos Fusarium oxysporum Schlecht, Rhizoctonia solani Kühn y Sclerotium rolfsii Sacc asociados a las pudriciones secas, ocasionaron un efecto depresivo en las plantas de malanga producidas in vitro cultivadas en cámaras. La mezcla de estos tres hongos resultó muy agresiva, lo que provocó en las plantas una disminución en la altura, el peso fresco del follaje y en el número de raíces, cormos y cormelos.

Depressive effect was determined on plants produced in vitro taro cultivar 'Amarilla Especial', fungi Fusarium oxysporum Schlecht, Rhizoctonia solani Kühn and Sclerotium rolfsii Sacc isolated from infected plants with symptoms of poor development, chlorosis, leaf necrosis and rot the roots. Treatments consisted of the isolation of the three fungi separately, the mixture of the three fungi and uninoculated control. Previously acclimatized plants were planted in chambers had dimensions 0.90 x 0.90 x 0.90 m, in randomized complete block with four replications. 100 plants were inoculated for each treatment and control is left as an equal number of uninoculated plants was evaluated in each case the plant height, number of roots per plant and number of diseased roots and subsequently determined the fresh weight and dry the roots and foliage. Was harvested at 10 months after planting and assessed some components of performance, as the number of corms and cormels and their fresh weight, as the intensity of damage at the time of harvest. The results showed that the fungal pathogens Fusarium oxysporum Schlecht, Rhizoctonia solani Kühn and Sclerotium rolfsii Sacc associated with dry rot caused a depressive effect on taro plants grown in vitro produced cameras. The mixture of these three fungi was very aggressive, resulting in reduced plant height, fresh weight of leaves and number of roots, corms and cormels.

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El objetivo del presente trabajo fue evaluar las propiedades físicas y nutricionales de las harinas extrudidas de plátano verde, ocumo chino o taro y sus mezclas con maíz, para diversificar la producción y el uso potencial en la agroindustria. El plan de investigación se realizó con un extrusor de laboratorio, tipo monotornillo a una temperatura de alimentación 75 ºC, temperatura del barril y de la matriz 180 ºC, velocidad del tornillo 120 rpm y 16 por ciento en el contenido de humedad de las harinas. Bajo estas condiciones, se obtuvo a partir de la harina de plátano verde un extrudido de alta densidad y bajo índice de expansión, mientras que con las mezclas por separado de la harina de ocumo chino y de plátano verde con un 80 por ciento de la harina de maíz blanco, resultaron extrudidos con baja densidad y alto índice de expansión, encontrándose diferencias estadísticamente significativas (p< 0,05) en las medidas del color (“L”). Con relación a la composición nutricional, se determino que todos los extrudidos presentaron un alto contenido de almidón resistente (22 por ciento) y variaciones en el contenido de fibra dietética en el intervalo de 8,4 por ciento a 2,88 por ciento. En conclusión los extrudidos de plátano verde por su aporte en almidón resistente, fibra dietética y una digestión lenta del almidón, se podrían recomendar en alimentos precocidos para regimenes especiales de alimentación. La obtención de extrudidos de ocumo chino permitiría diversificar el uso potencial de este rubro en la industria de alimentos.

The object of the present study, was to evaluate the physical and nutritional properties of the extruded flours ofgreen plantain, taro, and their mixture with corn, to diversify the production and the potential use in the agro industry The researching plan was made with a laboratory extruder single screwed type; to a feeding temperature of 75 ºC, barrel and matrix temperature of 180 ºC, screw speed of 120 rpm, and an humidity content of 16 percent in the flours. Under these conditions, it was obtained an green plantain flour based extrusion, of high density and low ratio of expansion; in the meantime, the separated mixtures of taro and green plantain with an 80 percent white corn flour, gave as results extrudates with low density and high level of expansion, and statistically significant differences were found (p< 0,05) in the color measure (“L”). In relation with the nutritional composition, it was determined that all the extrudates presented a high content of resistant starch (22 percent), and variations in the content of dietary fiber in the interval from 8,4 percent to 2,88 percent. Finally, the green plantain extrudates, for their contribution in resistant starch, dietary fiber and slow digestion of starch; could be recommended in precooked foods for special nutrition regimes. The obtention of taro extrudates, would allow to diversify the potential use of this product in the food industry.

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