Improving self-defense in plants. Martial arts for vegetables*

Abstract: From the dawn of agriculture there has been an ever-intensifying human effort to improve yields by having crops with enhanced biological similarity (i.e., characteristics of product, maturation time, height, color, etc.). The ultimate stage is to plant a crop where all individuals behave in exactly the same way, being clones of each other. This very intensive approach leads to loss of intrapopulation biodiversity and to unstable systems, prone to disastrous losses should anything go wrong. Biological evolutionary success is usually derived from high adaptability to everchanging external conditions. Highly specialized plants (such as certain orchids) or animals survive by correctly performing a high-wire act of enormous risk. External disbalances have catastrophic results on these species. Nature excels and corrects imbalances increased biodiversity within natural populations. Given this situation, we should study the defensive systems used by plants and improve on those natural systems

Effect of Acid Treatment on Interfacial and Foam Properties of Soy Proteins

The goal of the present work was to study the effects of acid treatment on the foaming properties of a soybean protein isolate (SPI) and its fractions, glycinin (11S) and β-conglycinin (7S). The structural characteristics, interfacial properties, foaming capacity and stability of the treated proteins were studied. Results from surface hydrophobicity and differential scanning calorimetry (DSC) showed that the acid treatment caused the complete denaturation of 11S and a partial denaturation of 7S. This protein unfolding affected their interfacial properties, which led to an improvement in the foaming properties of both protein fractions and isolate. Treated 7S showed the best behavior in the rearrangement process, probably due to its smaller size and its modified structural characteristics. All treated proteins showed stronger interfacial films. The foams of treated proteins were destabilized mostly due to gravitational drainage rather than Ostwald ripening.Centro de Investigación y Desarrollo en Criotecnología de AlimentosConsejo Nacional de Investigaciones Científicas y Técnica

Effect of Acid Treatment on Interfacial and Foam Properties of Soy Proteins

The goal of the present work was to study the effects of acid treatment on the foaming properties of a soybean protein isolate (SPI) and its fractions, glycinin (11S) and β-conglycinin (7S). The structural characteristics, interfacial properties, foaming capacity and stability of the treated proteins were studied. Results from surface hydrophobicity and differential scanning calorimetry (DSC) showed that the acid treatment caused the complete denaturation of 11S and a partial denaturation of 7S. This protein unfolding affected their interfacial properties, which led to an improvement in the foaming properties of both protein fractions and isolate. Treated 7S showed the best behavior in the rearrangement process, probably due to its smaller size and its modified structural characteristics. All treated proteins showed stronger interfacial films. The foams of treated proteins were destabilized mostly due to gravitational drainage rather than Ostwald ripening.Centro de Investigación y Desarrollo en Criotecnología de AlimentosConsejo Nacional de Investigaciones Científicas y Técnica

Morphological and chemical diversity in the Type IV glandular trichomes of Solananeae (S. sisymbrifolium and N. glauca) as germplasm resources for agricultural and food uses

Morphological variation in type IV trichomes in Ss and Ng was studied through SEM. The differences can be related to chemical differences in the excreted sugar esters. Ng trichomes exude two fractions, one of glucose tri-esters and the other one of sucrose tetra-esters, in a 3:7 ratio. The main acid found forming these esthers, is 3-methylvalerianic acid, in consonance to those secreted by other Solanaceae. Esters from Ss are novel structures, which can also be separated into three fractions, two of arabinoxylans, and the other one of arabinose, all glycosilated with \u3b2-hydroxipalmitic acid and sterified with the C12-C16 acids. All five fractions have antifungic activity at \u3bcg/cm2 concentrations, both against common and mycotoxigenic fungi, such as A. niger , A. flavus, P. chrysogenum y P. expansum. A. flavus does not grow in the presence of the SE of Ss and is not insensible to those from Ng, but these last are more effective in the inhibition of P. expansum, the other mycotoxigenic fungi studied. The differential antifungal activity observed gives the plant protection against a wide spectrum of fungi, resulting in a better adaptation to the environment. Both plants are common weeds, with the potential of contributing to germplams lines in the improvement programmes of crops such as L. esculentum, and their extracts can be used as natural fungicides to protect crops and plantations

Morphological and chemical diversity in the Type IV glandular trichomes of Solananeae (S. sisymbrifolium and N. glauca) as germplasm resources for agricultural and food uses

Morphological variation in type IV trichomes in Ss and Ng was studied through SEM. The differences can be related to chemical differences in the excreted sugar esters. Ng trichomes exude two fractions, one of glucose tri-esters and the other one of sucrose tetra-esters, in a 3:7 ratio. The main acid found forming these esthers, is 3-methylvalerianic acid, in consonance to those secreted by other Solanaceae. Esters from Ss are novel structures, which can also be separated into three fractions, two of arabinoxylans, and the other one of arabinose, all glycosilated with \u3b2-hydroxipalmitic acid and sterified with the C12-C16 acids. All five fractions have antifungic activity at \u3bcg/cm2 concentrations, both against common and mycotoxigenic fungi, such as A. niger, A. flavus, P. chrysogenum y P. expansum. A. flavus does not grow in the presence of the SE of Ss and is not insensible to those from Ng, but these last are more effective in the inhibition of P. expansum, the other mycotoxigenic fungi studied. The differential antifungal activity observed gives the plant protection against a wide spectrum of fungi, resulting in a better adaptation to the environment. Both plants are common weeds, with the potential of contributing to germplams lines in the improvement programmes of crops such as L. esculentum, and their extracts can be used as natural fungicides to protect crops and plantations

Comparison of Interfacial and Foaming Properties of Soy and Whey Protein Isolates

A comparative study on the foaming properties and behavior at the air-water interface of soy and whey protein isolates were made. Foams were obtained by the method of gas bubbling. The initial rate of passage of liquid to the foam (vi) and the maximum volume of liquid incorporated to the foam (VLEmax) were determined. The destabilization process of the formed foams was analyzedby a biphasic second order equation. Measurements of equilibrium surface tension (water/air) and surface rheological properties were carried out in a dynamic drop tensiometer. The foaming capacity (vi and VLEmax) and the stability of foams prepared with the whey protein isolates (WPI) were better than those formulated with the soy protein isolates (SPI). WPI foams were more stable showing the lower values of rate constants of gravity drainage and disproportion. There were significant differences (P ≤ 0.05) in the dilatational modulus in the surface rheology measurements, which were higher at the interface with WPI, implying greater resistance of the film formed to collapse and disproportion. In conclusion, WPI formed better and more stable foams than the SPI.Fil: Abirached, Cecilia. Universidad de la República; UruguayFil: Medrano, Claudia Alejandra. Universidad de la República; UruguayFil: Araujo, Ana Claudia. Universidad de la República; UruguayFil: Moyna, Patrick. Universidad de la República; UruguayFil: 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: Panizzolo, Luis Aberto. Universidad de la República; Urugua

Estabilidad de espumas formuladas con proteínas de soja tratadas a pH ácido

Se estudió la influencia del tratamiento a pH ácido de aislados proteicos de soja sobre las propiedades espumantes mediante el análisis de las constantes cinéticas de desproporción y drenado y el relacionamiento de éstas con los parámetros de reología interfacial. Los aislados proteicos de soja fueron obtenidos a partir de harina desgrasada. Una porción se llevó a pH 8,0 y otra porción se trató a pH 2,0. De la porción a pH 2,0 una parte se dejó a este pH y otra parte se neutralizó a pH 8,0. Todas las porciones se liofilizaron. Para la identificación y caracterización estructural de las muestras se realizaron análisis de electroforesis desnaturalizante, calorimetría diferencial de barrido, solubilidad e hidrofobicidad superficial. Se obtuvieron espumas por el método de burbujeo de gas. Se determinó la velocidad inicial de pasaje de líquido a la espuma y el volumen máximo de líquido incorporado a la espuma. El proceso de desestabilización de las espumas formadas se analizó ajustando los datos obtenidos a una cinética de segundo orden bifásica. Se realizaron estudios de reología interfacial con un tensiómetro de gota. El tratamiento a pH ácido mejoró tanto la espumabilidad como la estabilidad de las espumas. La proporción de líquido drenado por escurrido gravitatorio fue significativamente superior al volumen drenado debido a la desproporción. El tratamiento a pH 2,0 redujo la desestabilización por desproporción de Ostwald, lo que sugiere la formación en la interfase de una película más cohesiva, que se confirma con los parámetros de reología interfacial.In this work the influence of the acid pH treatment of soy protein isolate on the foaming properties by analysis of the kinetic constants of disproportion and drainage and their relation with the interfacial rheology parameters was studied. Soy protein isolates were obtained from defatted flour. A portion was brought to pH 8.0, another portion was treated at pH 2.0. From the portion treated at pH 2.0 a portion was left at this pH and another was neutralized to pH 8.0. All portions were lyophilized. For the identification and structural characterization of the samples were performed denaturing electrophoresis analysis, differential scanning calorimetry, solubility and surface hydrophobicity. Foams were obtained by the method of gas bubbling. The initial rate of passage of liquid to foam and the maximum volume of fluid incorporated to the foam were determined. The process of destabilization of foams formed was analyzed by fitting the data to a biphasic second-order kinetics. Studies were performed with an interfacial rheology drop tensiometer. Acid pH treatment improved both the foam and foam stability. The proportion of liquid drained by gravity was significantly higher than the drained volume because of the disproportion. Treatment at pH 2.0 reduced the Ostwald disproportion destabilization, suggesting the formation at the interface of a more cohesive film, which is confirmed by the interfacial rheology parameters.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Desestabilización de emulsiones aceite-agua preparadas con proteínas de soja

En este trabajo se realizó un estudio de las propiedades emulsionantes de las proteínas de soja glicinina y β-conglicinina en comparación con el aislado proteico de soja. Para esto se aislaron las fracciones por precipitación isoeléctrica, se les determinó la solubilidad, hidrofobicidad superficial y comportamiento térmico. Se estudió la estabilidad frente al cremado de las emulsiones por medio de un analizador óptico vertical y se establecieron dos constantes de desestabilización correspondientes a los tamaños de partícula observados con un analizador de partículas, mediante una ecuación de segundo orden bifásica (Panizzolo, 2005). Se determinó que las emulsiones preparadas con glicinina son las más inestables en cuanto al cremado y que las preparadas con β-conglicinina presentan un comportamiento similar al aislado proteico de soja

Estabilidad de espumas formuladas con proteínas de soja tratadas a pH ácido

Se estudió la influencia del tratamiento a pH ácido de aislados proteicos de soja sobre las propiedades espumantes mediante el análisis de las constantes cinéticas de desproporción y drenado y el relacionamiento de éstas con los parámetros de reología interfacial. Los aislados proteicos de soja fueron obtenidos a partir de harina desgrasada. Una porción se llevó a pH 8,0 y otra porción se trató a pH 2,0. De la porción a pH 2,0 una parte se dejó a este pH y otra parte se neutralizó a pH 8,0. Todas las porciones se liofilizaron. Para la identificación y caracterización estructural de las muestras se realizaron análisis de electroforesis desnaturalizante, calorimetría diferencial de barrido, solubilidad e hidrofobicidad superficial. Se obtuvieron espumas por el método de burbujeo de gas. Se determinó la velocidad inicial de pasaje de líquido a la espuma y el volumen máximo de líquido incorporado a la espuma. El proceso de desestabilización de las espumas formadas se analizó ajustando los datos obtenidos a una cinética de segundo orden bifásica. Se realizaron estudios de reología interfacial con un tensiómetro de gota. El tratamiento a pH ácido mejoró tanto la espumabilidad como la estabilidad de las espumas. La proporción de líquido drenado por escurrido gravitatorio fue significativamente superior al volumen drenado debido a la desproporción. El tratamiento a pH 2,0 redujo la desestabilización por desproporción de Ostwald, lo que sugiere la formación en la interfase de una película más cohesiva, que se confirma con los parámetros de reología interfacial