Functional properties of guava seed glutelins

Five guava seed glutelin extracts were obtained with different buffer solutions: Na2B4O7 alone (Glut.Bo) or containing SDS (Glut.BoSDS), 2-mercaptoethanol (Glut.Bo2-ME), or a combination of both (Glut.BoSDS2-ME) and NaOH (Glut.Na). All borate buffer solutions were at pH 10. The higher yield of glutelins corresponded to the Glut.BoSDS extract (81.9% dry basis) and the lower to Glut.Bo (6.8%). The functional properties of the five guava seed glutelin extracts were determined. Glut.BoSDS, Glut.BoSDS2-ME, and Glut.Na showed high values for several properties, including surface hydrophobicity (7.7, 10.8, and 0.6, respectively), solubility at pH 10 (91.1, 77.9, and 96.7, respectively), water-holding capacity at pH 3.6 (1.7, 2.5, and 2.8, respectively), emulsifying activity index (pH 10; 503.5, 238.2, and 838.0, respectively), and foaming properties (pH 10; V0 = 0.14, 0.25, and 0.19, respectively; Vmax = 6.1, 5.59, and 4.51, respectively; t1/2 = 266, 255.3, and 94 s, respectively). These results suggest that the denaturing reagent (SDS or NaOH) during extraction conferred on the proteins a structure that facilitated the development of their functional properties.Fil: Bernardino Nicanor, Aurea. INSTITUTO POLITÉCNICO NACIONAL (IPN);Fil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Scilingo, Adriana Alicia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Dávila Ortíz, Gloria. INSTITUTO POLITÉCNICO NACIONAL (IPN)

Functional Properties of Guava Seed Glutelins

Five guava seed glutelin extracts were obtained with different buffer solutions: Na2B4O7 alone (Glut.Bo) or containing SDS (Glut.BoSDS), 2-mercaptoethanol (Glut.Bo2-ME), or a combination of both (Glut.BoSDS2-ME) and NaOH (Glut.Na). All borate buffer solutions were at pH 10. The higher yield of glutelins corresponded to the Glut.BoSDS extract (81.9% dry basis) and the lower to Glut.Bo (6.8%). The functional properties of the five guava seed glutelin extracts were determined. Glut.BoSDS, Glut.BoSDS2-ME, and Glut.Na showed high values for several properties, including surface hydrophobicity (7.7, 10.8, and 0.6, respectively), solubility at pH 10 (91.1, 77.9, and 96.7, respectively), water-holding capacity at pH 3.6 (1.7, 2.5, and 2.8, respectively), emulsifying activity index (pH 10; 503.5, 238.2, and 838.0, respectively), and foaming properties (pH 10; V0 ) 0.14, 0.25, and 0.19, respectively; Vmax ) 6.1, 5.59, and 4.51, respectively; t1/2 ) 266, 255.3, and 94 s, respectively). These results suggest that the denaturing reagent (SDS or NaOH) during extraction conferred on the proteins a structure that facilitated the development of their functional properties.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Influence of starch source in the required hydrolysis time for the production of maltodextrins with different dextrose equivalent

The starches were statistically different (p < 0.05) in their protein, ash, fat, phosphorus, amylose and amylopectin content. The amylose/amylopectin ratios in corn, potato and rice starches were 0.389, 0.282 and 0.220, respectively. The phosphorus content in the same order of starches was: 0.15 ± 0.01; 0.80 ± 0.02 and 0.95 ± 0.02 g/kg, respectively. The chemical composition of the different starches, and specifically its amylose and amylopectin content, its phosphorus content and the way it is bound to the starch molecule, affect the functional properties like the viscosity of gels and the enzymatic hydrolysis rate of these molecules. The rice starch is easily hydrolyzed by the á-amylase enzyme from Aspergillus oryzae and therefore, it required less time to obtain maltodextrin by enzymatic hydrolysis from rice starch compared with those from corn or potato starch. Under saturation conditions of the enzyme, the dextrose equivalent content was proportional to the hydrolysis time, regardless of the starting starch source.Key words: Starch, maltodextrins, dextrose equivalent, amylose, amylopectin

Effect of the fructose and glucose concentration on the rheological behavior of high fructose syrups

The objective of this work was to study the effect of fructose and glucose content on the rheological behavior of syrups. Initially, high fructose syrup from the fructans present in leaves, bases and head of Agave tequilana Weber blue was obtained. Then, its contents of moisture, ash, fructose, glucose and direct and total reducing sugars were determined. Finally, the physicochemical properties of the syrups were evaluated and compared with a high commercial fructose corn syrup (Frudex 55) and other fructose, glucose and sucrose syrups. All of them had the same temperature and concentration of total solids. All syrups behaved as Newtonian fluids and had no statistically significant differences (p <0.05) in their density, water activity and in direct and total reducing sugars. The viscosity and surface tension of syrup depended on its fructose and glucose content. Also, greater fructose content produces syrups with lower viscosity and lower surface tension.Keywords: High fructose syrups, viscosity, rheological behavior, Newtonian fluidsAfrican Journal of Biotechnology, Vol. 12(12), pp. 1401-140

MECANISMOS DE SILENCIAMIENTO GÉNICO DURANTE EL DESARROLLO DEL GAMETOFITO FEMENINO EN Arabidopsis thaliana (MECHANISMS OF GENE SILENCING DURING THE DEVELOPMENT OF THE FEMALE GAMETOPHYTE IN Arabidopsis thaliana)

ResumenSilenciar un gen significa disminuir la expresión del mismo y a partir de los efectos, afectar su función, actuando a diferentes niveles, por ejemplo, silenciamiento transcripcional (TGS), silenciamiento post-transcripcional (PTGS) y traduccional. Los cuales, presentan elementos comunes mediados por ARNs pequeños (RNAp), que proporcionan especificidad y se acomplejan con proteínas efectoras del silenciamiento génico. Recientemente se reportó la participación de ARNs pequeños  en la determinación de la identidad de la célula madre de la megaspora. En este trabajo se plantea una estrategia para estudiar las rutas de silenciamiento que participan en la regulación de la identidad celular durante el desarrollo del gametofito femenino. Para lo anterior se generaron líneas silenciadoras del gen GUS (GUSRNAi). Posteriormente se seleccionaron algunas de estas líneas para ser cruzadas con los marcadores del desarrollo del gemetofito femenino. Se obtuvieron imágenes que reflejaron la actividad de las líneas marcadoras durante el desarrollo reproductivo. En las plantas de la línea GUSRNAi;Marcadora se observó una expresión atenuada o nula del marcador de identidad. Lo anterior demostró la capacidad de la lineas para llevar a cabo silenciamiento génico en células del gametofino femenino.Palabras clave: Gametogénesis, linaje celular, ARNs. AbstracSilencing a gene means decreasing its expression affecting its function, acting at different levels, for example transcriptional silencing (TGS), post-transcriptional silencing (PTGS) and translational silencing. They present common elements mediated by small RNAs (RNAs), which provide specificity and form complexes with gene silencing effector proteins. The participation of small RNAs in the determination of the identity of the megaspore mother cell was recently reported. In this work, a strategy is proposed to study the gene silencing pathways involved in the regulation of cell identity during the development of the female gametophyte. For this, we generated silencing lines of the GUS gene (GUSRNAi). Subsequently, some of these lines were selected to be crossed with the developmental marker of the female gametophyte, ET2209. Images that reflected the activity of the marker lines during reproductive development were obtained. While in plants GUSRNAi;ET2209 we observed an attenuated or null expression of the identity cell marker. The above demonstrated the ability of these lines to carry out gene silencing in female gametophyte cells.Keywords: Gametogenesis, cell lineage, RNAs

Agave Seeds: Physical and Chemical Characterization and Identification of Storage Proteins

ABSTRAC

Quistes del ovario, su curación radical : Tesis para el doctorado en medicina

Incluye nómina de Catedráticos y Asignaturas. Tesis con dedicatoria

Efecto de la utilización de bagazo de naranja como extensor funcional sobre las propiedades fisicoquímicas y texturales de jamón cocido

The substitution effect of carrageenan, soy protein and potato starch by orange bagasse on physico-chemical characteristics of cooked ham was evaluated. A 33 factorial design was used, with substitution levels of 0, 50 and 100%. The results indicate that the substitution of potato starch for orange bagasse results in increase in the ham yield, but to replace the carrageenan and/or soy protein by orange bagasse, cause decrease in yield below that non-substituted ham. Moreover, if even yields increase with substitution of potato starch by orange bagasse, however, the textural characteristics of the product obtained showed deficiency in comparison with thenon-substituted ham. Apparently orange bagasse substitution does not alter the matrix stability formation in ham, so there was no significant difference in expressible moisture. Substitution of carrageenan, soy protein and potato starch by orange bagasse in ham has highest influence on pH and color parameters, this due probably to compounds presents in the fruit (citric acid and carotenoids). Orange bagasse has high potential as a novel source of dietary fiber in food industry.Se evaluó el efecto de la sustitución de la carragenina, fécula de papa y proteína de soya, por bagazo de naranja sobre las características físico-químicas de jamón cocido, para lo cual se utilizó un diseño factorial 33, teniendo como niveles de sustitución de cada componente 0, 50 y 100%, los resultados indicaron que la sustitución de fécula de papa por bagazo de naranja, permite obtener menores pérdidas con respecto a la muestra estándar por efecto del tratamiento térmico, sin embargo al sustituir la carragenina o proteína de soya, las pérdidas se incrementan. Por otra parte, aun cuando los rendimientos se incrementan con la sustitución de fécula de papa por bagazo de naranja, el producto muestra deficientes características texturales en comparación con la muestra estándar. Aparentemente, la sustitución con bagazo de naranja, no altera la estabilidad de la matriz formada en el jamón, por lo que no hubo diferencia significativa en la humedad exprimible. Los parámetros en los que se observó mayor influencia de la sustitución con bagazo fueron pH y color, esto se debe a los compuestos que contiene el fruto (ácido cítrico y carotenoides). El bagazo de naranja tiene un alto potencial para ser utilizado en la industria cárnic