Cambios microestructurales en los granos de Phaseolus vulgaris endurecidos / Microstructural changes in hardened beans (Phaseolus vulgaris)

El endurecimiento de los granos de Phaseolus vulgaris almacenados a alta temperatura y alta humedad relativa es una de las principales limitantes para su consumo. El objetivo de esta investigación fue evaluar por microscopia de barrido electrónico los cambios estructurales ocurridos en los cotiledones y en la testa de los granos endurecidos. Los granos recién cosechados se almacenaron durante doce meses bajo dos condiciones: 5°C-34% HR y 37°C-75% HR. Esta última con el fin de propiciar el endurecimiento. Los granos almacenados crudos y cocidos se liofilizaron y se fracturaron. Las secciones de testa y cotiledones se observaron en un microscopio electrónico JSM-6390. Al cabo de doce meses se constató que los granos almacenados a 37°C-75% HR aumentaron su dureza en un 503%, mientras que los granos almacenados a 5°C-34% HR no incrementaron su dureza significativamente. A nivel microestructural, en los cotiledones de los granos crudos se notaron claras diferencias en el aspecto de la pared celular, en el tamaño del espacio intercelular y en la textura de la matriz proteica. Mientras que en la testa de los granos crudos se evidenciaron diferencias en la compactación de la empalizada y de la capa sub-epidérmica. En los granos cocidos se observó una total separación entre las células de los cotiledones de los granos blandos y una muy limitada separación en los granos duros. Se concluye que las diferencias observadas en los granos duros y blandos, demostraron una participación importante de ambas estructuras, cotiledones y testa, en el endurecimiento de los granos.

The hardening of Phaseolus vulgaris beans stored at high temperature and high relative humidity is one of the main constraints for consumption. The objective of this research was to evaluate by scanning electron microscopy, structural changes in cotyledons and testa of the hardened beans. The freshly harvested grains were stored for twelve months under two conditions: 5 ° C-34% RH and 37 ° C-75% RH, in order to promote hardening. The stored raw and cooked grains were lyophilized and fractured. The sections of testa and cotyledons were observed in an electron microscope JSM-6390. After twelve months, grains stored at 37 ° C-75% RH increased their hardness by 503%, whereas there were no significant changes in grains stored at 5 ° C-34% RH. At the microstructural level, the cotyledons of the raw grains show clear differences in appearance of the cell wall, into the intercellular space size and texture matrix protein. There were also differences in compaction of palisade and sub-epidermal layer in the testa of raw grains. After cooking, cotyledon cells of the soft grains were well separated while these of hard grains were seldom separated. In conclusion, the found differences in hard and soft grains showed a significant participation of both structures, cotyledons and testa, in the grains´ hardening.

Efeitos da faseolamina, farinhas de feijão cru e cozido no perfil nutricional e bioquímico de ratos jovens saudáveis / Effects of phaseolamine, white bean raw and baked flours on the nutritional status and biochemical profile of healthy young rats

OBJECTIVE: To evaluate the effect of phaseolamine, white bean raw and baked flours on the nutritional status and biochemical profile of young healthy rats. Methods: We used 28 male rats, divided into 4 groups, receiving the following diets: C - standart diet; FA - standard diet added with phaseolamine (9g/kg of body weight); FF - standard diet with white bean raw flour (9g/kg of body weight); and FC - standard diet with white bean baked flour (9g/kg of body weight). The animals were kept in a controlled environment, receiving their respective diets and water ad libitumfor 28 days. The following variables were taken weekly: body weight, food and water intakes, urinary and fecal excretion. At the end of the study, blood collection was carried out for biochemical (glucose, lipid, liver and kidney profiles) and organ determinations for weight comparison between groups. RESULTS: It was possible to verify that the use of white bean raw flour, white bean baked flour, or phaseolamine showed no significant changes in the results of any of the variables analyzed. CONCLUSIONS: The use of phaseolamine and white bean raw and baked flours has no effects on the nutritional status and biochemical profile of young healthy rats

OBJETIVO: Avaliar o efeito da faseolamina, farinhas de feijão branco cru e cozido no perfil nutricional e bioquímico de ratos jovens saudáveis. MÉTODOS: Foram utilizados 28 ratos, machos, distribuídos em quatro grupos, recebendo: C ­ dieta padrão; FA ­ dieta padrão e acréscimo de faseolamina (9g/kg de peso corporal); FF ­ dieta padrão com farinha de feijão branco cru (9g /kg de peso corporal); FC ­ dieta padrão com farinha de feijão branco cozido (9g/kg de peso corporal). Os animais permaneceram em ambiente controlado, recebendo a respectiva dieta e água ad libitum por 28 dias. Foram coletados semanalmente peso corporal, consumo alimentar, ingestão hídrica, excreção urinária e fecal. Ao final do estudo realizou-se coleta de sangue para determinações bioquímicas (perfil glicídico, lipídico, hepático e renal) e de órgãos para comparação do peso entre grupos. RESULTADOS: Verificou-se que o uso da farinha de feijão branco cru, farinha de feijão branco cozido ou faseolamina não resultou em alterações significativas em quaisquer das variáveis analisadas. CONCLUSÕES: A utilização de faseolamina e farinha de feijão branco cru não possui efeitos sobre o estado nutricional e bioquímico de ratos jovens saudáveis

Respuesta glicémica al consumo de una barra de cereales-leguminosa (Phaseolus vulgaris) en individuos sanos / Glycemic response to consumption of a cereals and legume (Phaseolus vulgaris) bar on healthy individuals

El objetivo de la presente investigación fue formular una barra de cereales y leguminosa (Phaseolus vulgaris) y evaluar su impacto sobre la respuesta glicémica de individuos sanos, a fin de contribuir con la oferta de alimentos beneficiosos para la salud del consumidor. Para esto se formuló una barra con una mezcla de cereales (maíz y avena) y dos porcentajes (20% y 30%) de Phaseolus vulgaris. Adicionalmente, se preparó una barra de cereales sin leguminosa (barra control). Mediante evaluación sensorial, se seleccionó la barra con 30% de Phaseolus vulgaris, por ser evaluada con mejor sabor y textura, además esa combinación de cereales y leguminosas favorece la complementación aminoacídica y los criterios de formulación previamente establecidos. La caracterización química indicó un contenido de proteínas mayor en la barra con 30% de Phaseolus vulgaris (13,55%), en relación a la barra control (8,5%). Los contenidos de grasa, cenizas y fibra dietética no presentaron diferencias (p>0,05) entre ambas barras evaluadas. Sin embargo, el contenido de fibra soluble y de almidón resistente de la barra seleccionada resultó un 32,05% y 18,67% mayor, respectivamente, que en la barra control, con lo cual se podría contribuir con la disminución de la velocidad de absorción de la glucosa. La barra seleccionada presentó un índice glicémico bajo (49) y carga glicémica intermedia (12,0) en voluntarios sanos, lo que podría traducirse en una posible reducción de la tasa de absorción de glucosa al torrente sanguíneo, asociada a un contenido de carbohidratos de absorción lenta. La barra formulada representa una propuesta de merienda saludable para el consumidor.

The objective of this work was to formulate a cereals and legume (Phaseolus vulgaris) bar and assess its impact on the glycemic response of healthy individuals, in order to contribute to the healthy food supply beneficial to consumers. A mixture of cereals (corn and oats) and different percentages (20 and 30%) of Phaseolus vulgaris was used to formulate the bar. Additionally, a legume cereal bar without legumes (bar control) was prepared. The bar with 30% of Phaseolus vulgaris was selected through sensory evaluation, being scored with better flavor and texture. This combination of cereals and legumes aminoacid improves complementation and reaches the formulation criteria previously established. Chemical characterization indicated a higher protein content in the bar with 30% of Phaseolus vulgaris (13,55%) relative to the bar control (8,5%). The contents of fat, ash and dietary fiber did not differ between the two bars evaluated. However, the soluble fiber and resistant starch of the selected bar was a 32,05% and 18,67%, respectively, than in the control bar; this may contribute to decreasing the rate of glucose uptake. The selected bar presented a low glycemic index (49) and intermediate glycemic load (12,0) in healthy volunteers, which could lead to a possible reduction in the rate of absorption of glucose into the bloodstream, associated with a carbohydrate content of slow absorption. This bar represents a proposal of a healthy snack for the consumer.

Antioxidant activity of commonly consumed cereals, millets, pulses and legumes in India.

Plant foods are important due to their antioxidant activity (AOA) attributed to the phenolics which are known to protect organisms against harmful effects of oxygen radicals. However, information on antioxidant activity of Indian plant foods is scanty. Therefore, the present study evaluated the AOA of cereals, millets, pulses and legumes, commonly consumed in India and assessed the relationship with their total phenolic content (TPC). AOA was assessed by DPPH (2,2-Diphenyl-1-picryl hydrazyl) radical scavenging assay, ferric reducing antioxidant power (FRAP) assay and reducing power. DPPH scavenging activity ranged from 0.24 and 1.73 mg/g, whereas FRAP ranged from 16.21 to 471.71 micromoles/g. Finger millet (Eleusine cora cana) and Rajmah (Phaseolus vulgaris) had the highest FRAP 471.71, 372.76 and DPPH scavenging activity 1.73, 1.07. Similar trends were observed with reducing power. Among cereals and legumes, Finger millet (Ragi) and black gram dhal (Phaseolus mungo Roxb) had the highest TPC, the values being 373 and 418 mg/100 g respectively, while rice (Oryza sativa) and green gram dhal (Phaseolus aureus Roxb) showed the least (47.6 and 62.4 mg/100 g). In the present study, FRAP (r = 0.91) and reducing power (r = 0.90) showed significant correlation with TPC in cereals and millets, but not in pulses and legumes. The results suggest that TPC contributes significantly to the AOA of Indian cereals and millets.

Desarrollo de un alimento de humedad intermedia de fréjol (Phaseolus vulgaris L.)

El consumo de fréjoles se ha asociado a la reducción del riesgo de desarrollo de enfermedades crónicas no transmisibles. En general, su consumo es menor al recomendado y se realiza mayoritariamente como granos enteros. Para aumentar su consumo, hay un especial interés en su uso en otras formas. El objetivo de esta investigación fue diseñar purés de humedad intermedia (PHI) de fréjol de buena calidad química, microbiológica y sensorial. Se prepararon purés con fréjol Tórtola remojado, cocido y molido, retirando una parte importante de la testa. En la elaboración de los PHI, se estudiaron dos niveles de humedad, 25% y 30%, y dos niveles de glicerol, 10 y 15%. Se conservaron a temperatura ambiente (20 ±2 ºC) por 30 días. En los purés iniciales se determinó su composición proximal, contenido de fitatos e inhibidores de tripsina. Los PHI se analizaron el día de su preparación y luego de 15 y 30 días de almacenamiento. Se determinó su humedad, pH y actividad de agua. Se realizó recuento total de: aerobios mesófilos, de mohos y levaduras, de coliformes totales, de coliformes fecales y de Staphylococcus aureus. Se determinó calidad y aceptabilidad sensorial. Los PHI tuvieron una aw entre 0,800 y 0,844, pH entre 6,20 y 6,24 y sus recuentos microbiológicos fueron negativos o estuvieron muy por debajo de los límites permitidos para los alimentos más exigentes. Presentaron buenas calificaciones en su calidad sensorial y todos fueron bien aceptados. Los parámetros sensoriales se mantuvieron sin variación durante el almacenamiento, excepto el color que en el tratamiento con 30% de humedad y 10% de glicerina mostró un leve oscurecimiento. Es posible elaborar purés de fréjol de humedad intermedia, con bajos niveles de compuestos antinutricionales, de buena calidad y aceptabilidad sensorial y que ofrecen condiciones adversas para el desarrollo de los microorganismos de mayor significación para la inocuidad alimentaria.

Development of an intermediate moisture food from bean (Phaseolus vulgaris L.). Beans consumption has been associated to reduction on chronic, non transmissible, diseases development. Generally, its consumption is less to the recommended and it is done principally as whole grain dishes. To increase the consumption, there is an especial interest in the use of new products. The main goal of this research was to design intermediate moisture bean purees (IMP) using soaked, cooked and grained Tortola bean, removing an important testa portion. In preparation of IMP two moisture levels, 25 and 30%, and two glycerol levels, 10 and 15%, were studied. Purees were preserved at ambient temperature (20 ±2 ºC) for 30 days. Proximal analysis, phytate content and trypsin inhibitors were determined in the original non processed purees. IMPs were analyzed at preparation time and after 15 and 30 days of storage for moisture content, pH and water activity. Besides, microbiological analysis for total plate count on aerobic mesophile microorganisms, molds and yeast, total colifoms, fecal coliforms and Staphylococcus aureus, was carried out. Global quality and sensory acceptance was also determined. IMPs presented aw values between 0.800 and 0.844, a pH between 6.20 and 6.24 and the microbiological counting was negative or far below the accepted limits for more strict foods. IMPs presented good qualifications for global quality and were well accepted. Sensory parameters maintain their values during storage, except for color that in treatment with 30% moisture and 10% glycerol showed a light darkening. It is possible to elaborate intermediate moisture bean puree, with low level of antinutritional compounds, good quality and sensory acceptance and with adverse conditions for the development of food safety importance microorganisms.

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.

Biological evaluation of the purified alpha amylase inhibitor from kidney bean [Giza 133]

The biological evaluation of the purified alpha amylase inhibitor of kidney bean [Giza 133] by using rats was carried out. Results showed that all rats gained weight at different levels. Rats in control groups gained more weight [64g] and faster than those with inhibitor. The results indicated that using 200 Ul/100g: diet was economically recommended. Diets supplemented with .200:Ul increased BV, NPU by [16%], and reduced starch hydrolysis. Glucose absorption in blood and serum insulin in all digestion hours, with little starch hydrolysis after 4 hr digestion noticed. The results also proved that using alpha amylase inhibitor in diet caused higher level of NEFA, reduction in the rate of forming fatty substances in subcutaneous layers in rats and consequently growing rate was reduced

Phaseolus vulgaris bioprocesada: una nueva alternativa al consumo de leguminosas / Bioprocesed phaseolus vulgaris: a new alternative to legume consumption

Las leguminosas constituyen una importante fuente de proteínas en los países subdesarrollados, sin embargo, suconsumo está limitado entre otras razones, por la flatulencia que se produce después de su ingesta. Los compuestos altamente fermentables en el colón y responsables de este fenómeno, son los a-galactósidos, la fibra soluble y el almidón resistente. El objetivo de este trabajo fue evaluar el efecto de la aplicación de bioprocesos, tales como la hidrólisis enzimática y la fermentación, sobre los compuestos productores de flatulencia en la variedad oscura Tacarigua de Phaseolus vulgaris. Adicionalmente, se midió el efecto de la cocción, sobre la concentración de los factores flatulentos de los granos ya fermentados. Se encontró que la fermentación natural reduce totalmente los a-galactosidos y en un 80 por ciento la fibra soluble presente en los granos. El almidón resistente no es afectado por los bioprocesos; solo disminuye entre 63 por ciento y 70 por ciento por acción de los procesos térmicos. La hidrólisis enzimática resultó ser el método menos efectivo para disminuir los compuestos flatulentos. Se concluyó que la fermentación natural es la metodología más sencilla y efectiva para disminuir los compuestos productores de flatulencia y que el proceso de cocción que se aplica al grano previo a su consumo, no modifica los efectos de la fermentación.

Legumes are an important source of vegetable protein in undeveloped countries; nevertheless, their consumption is limited, for the flatulence they produce among other factors. In the colon the highly fermentable compounds of Phaseolus vulgaris and responsible for the flatulence are the a-galactosides, soluble fiber and resistant starch. The objective of this work was to evaluate the effect of bioprocesses, like enzymatic hydrolysis and fermentation on the flatulent compounds of a black variety Tacarigua of Phaseolus vulgaris . Additionally, the effect of cooking, a necessary process to make beans edible, on the flatulence compounds of the fermented beans was evaluated. It was found that the natural fermentation decrease totally the ¦Á-galactosides and partially (80%) the soluble fiber in beans. Resistant starch was not affected by the bioprocesses; it decreases from 63% to 70% with the thermic process. Enzymatic hydrolysis was the worst method to diminish the flatulent compounds. It was concluded that the natural fermentation is the easiest and most effective method to decrease the flatulence compounds. The cooking required to make beans edible does not affect the fermentation effect on the flatulence factors of beans.

Hypocholesterolemic effect of protein prepared from Phaseolus aconitifolius (Jacq.).

Hypocholesterolemic effect of protein concentrate (PC) prepared from moth bean (Phaseolus aconitifolius Jacq.) seeds relative to that of pigeon pea PC and casein were investigated in rats fed on hypercholesterolemic diet containing two per cent cholesterol. The test diets containing casein and legume PCs at 10% protein level were fed to albino rats (Wistar strain) for 45 days. Compared to casein, the two legume PCs produced significantly lower levels of liver total lipid and cholesterol levels except that pigeon pea PC produced only non-significant decrease of total cholesterols in the heart. In addition, the legume PCs produced significantly lower levels of serum triglycerides and total lipids as well as lower levels of total and low-density lipoprotein cholesterol. Moreover, only moth bean PC produced a significantly higher level of serum high-density lipoprotein cholesterol. Generally, PC of moth bean seemed to be more potent at lowering the elevated hepatic and serum lipids and cholesterol levels, which were attributed to the amino acid profile of this lesser-known legume as these indices well correlated with serum cholesterol levels.

The resistance of seeds of cowpea (Vigna unguiculata) to the cowpea weevil (Callosobruchus maculatus)

Cowpea (Vigna unguiculata) seeds are heavily damaged during storage by the bruchid Callosobruchus maculatus. Seeds of some Nigerian varieties showed a strong resistance to this bruchid. By utilizing biochemical and entomological techniques we were able to rule out the paticipation of proteolytic enzyme (trypsin, chimotrypsin, subtilisin and papain) inhibitors, lectins, and tannins in the resistance mechanisms. Fractionation of the seed meal of a resistant variety suggests that the factor(s) responsible for the effect is (are) concentrate in the globulin fraction.