Pronase hydrolysis as a pretreatment for quantifying Maillard intermediates during toasting of cornflakes

Some of the products generated by the Maillard reaction are desired and very important for defining consumer acceptance of breakfast cereals. However, in recent years there has been an increased concern about compounds that are potentially harmful such as furfurals. The aim of this work was to analyze the effectiveness of protein hydrolysis with pronase as a pretreament for the evaluation of furfurals generated by the Maillard reaction during toasting of cornflakes and the parallel development of brown and fluorescent compounds. Furfurals were more accurately quantified with the pronase hydrolysis pretreatment because the protein matrix binds furfurals and fluorescent compounds. For control of the early reaction steps in the toasting process, the most sensitive parameter was fluorescence.EEA PergaminoFil: Cueto, Mario Alberto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Farroni, Abel Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio de Calidad de Alimentos, Suelos y Aguas; ArgentinaFil: Buera, María del Pilar. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Carotenoid and color changes in traditionally flaked and extruded products

The objective of this study was to evaluate the impact of process and formulation on individual carotenoid loss in traditionally prepared cornflakes and those prepared by extrusion. The first step in the traditional process (maize grits cooking) promoted a 60% lutein content reduction and 40% in zeaxanthin loss, showing lutein more susceptibility to isomerization and decomposition. After toasting, the last step, the total loss averaged 80% for both compounds. The extruded maize in a plain formulation showed a 35% lutein and zeaxanthin reduction. However, in samples containing quinoa the decrease reached 60%, and the major loss (80%) was found in chia-containing formulations. Correlations between the color coordinate b⁄, total and individual carotenoid content, were obtained. It is of a major importance that the efforts to increase carotenoid content in raw materials are complemented with attempts to reduce the losses during processing.EEA PergaminoFil: Cueto, Mario. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industria; ArgentinaFil: Farroni, Abel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio Calidad de Alimento, suelos y agua; ArgentinaFil: Schoenlechner, Regine. Universidad de Recursos Naturales y Ciencias de la Vida. Departamento de Ciencias y Tecnología de los Alimentos; AustriaFil: Schleining, Gerhard. Universidad de Recursos Naturales y Ciencias de la Vida. Departamento de Ciencias y Tecnología de los Alimentos; AustriaFil: Buera, Pilar. Cueto, Mario. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industria-Departamento de Química Orgánica; Argentin

Toasting time and cooking formulation affect browning reaction products development in corn flakes

During toasting, the last stage of corn flake production, Maillard reaction takes place, favored by the high temperature and low water content. The cooking formulation ingredients influence color and flavor of the final product and, therefore, consumer acceptance. However, some undesirable components are also formed. The impact of cooking formulation and toasting time on color development and on the formation of chemical markers was investigated. Samples (flakes) were equilibrated at water activity (aw) 0.8 and toasted at 230 ° C. After extraction of fluorescent pigments with pronase, fluorescence, absorbance at 420 nm, and furfurals analysis was performed. Sucrose showed a synergistic interaction with malt and salt. Formulation highly affected the amount of HMF and furfural formed. L* and a* were sensitive variables to measure overall browning reaction. These results allow for further understanding of the influence of formulation used during cooking and would help to mitigate the formation of undesirable compounds.EEA PergaminoFil: Cueto, Mario. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Perez Burillo, Sergio. Universidad de Granada. Facultad de Farmacia. Departamento de Nutrición y Ciencias de los Alimentos; EspañaFil: Rufián Henares, José. Universidad de Granada. Facultad de Farmacia. Departamento de Nutrición y Ciencias de los Alimentos; EspañaFil: Farroni, Abel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio de Calidad de Alimento, Suelos y Agua; ArgentinaFil: Buera, M. del Pilar. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentin

Efecto de la formulación y las condiciones de procesamiento sobre el desarrollo del pardeamiento no enzimático y la estabilidad de carotenoides en copos de maíz

El proceso de producción de copos de maíz por laminación comprende las etapas de cocción al vapor, atemperado, laminado y tostado. Durante la cocción y además en el tostado, ocurre la reacción de Maillard, favorecida por las elevadas temperaturas y el bajo contenido de agua en este último paso. Además, se produce la pérdida de compuestos de interés, como los carotenoides. Los diferentes ingredientes que constituyen la formulación de los copos de maíz influyen sobre el color y el flavor del producto final y, por lo tanto, sobre la aceptación por parte de los consumidores. Sin embargo, en el proceso también se forman ciertos compuestos indeseables. Por lo tanto, es importante evaluar el papel de la formulación y del tiempo de tostado en el desarrollo de color y la formación de marcadores químicos. Los copos de maíz se equilibraron a aw 0,8 y tostaron a 230ºC. Luego de la extracción de pigmentos fluorescentes con pronasa, se realizaron análisis de fluorescencia, absorbancia a 420 nm, coordenadas de color y contenido de furfurales. Por otro lado, se evaluó la estabilidad de los carotenoides en las distintas etapas del proceso de elaboración. Respecto a la formulación, la sacarosa mostró un efecto sinérgico con la sal y la malta para acelerar la reacción de Maillard. La formulación afectó significativamente la cantidad de HMF y furfural formados. Los parámetros cromáticos L* y a* fueron variables adecuadas para evaluar reacción de pardeamiento. Durante el proceso de cocción se perdió un 60% de luteína y un 40% de zeaxantina. Luego del tostado, la etapa final, el porcentaje de pérdida de ambos compuestos fue del 80%. Estos resultados permiten profundizar en el conocimiento de las reacciones que ocurren durante el procesamiento de los cereales, para poder definir las condiciones que disminuyan la generación de compuestos indeseables y la mayor retención de las sustancias de interés.EEA PergaminoFil: Cueto, Mario Alberto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industria y Química Orgánica; Argentina. Consejo Nacional de Investigaciónes Científicas y Tecnicas (CONICET); Argentina.Fil: Rolandelli, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industria y Química Orgánica; Argentina. Consejo Nacional de Investigaciónes Científicas y Tecnicas (CONICET); Argentina.Fil: Perez Burillo, S. Universidad de Granada. Facultad de Farmacia. Departamento de Nutrición y Bromatología; España.Fil: Rufián-Henares, J.A. Universidad de Granada. Facultad de Farmacia. Departamento de Nutrición y Bromatología; España.Fil: Farroni, Abel Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio Calidad de Alimento, Suelo y Agua; Argentina.Fil: Buera, María del Pilar. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industria y Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Tecnicas (CONICET); Argentina

Pronase hydrolysis as a pretreatment for quantifying Maillard intermediates during toasting of cornflakes

Some of the products generated by the Maillard reaction are desired and very important for defining consumer acceptance of breakfast cereals. However, in recent years there has been an increased concern about compounds that are potentially harmful such as furfurals. The aim of this work was to analyze the effectiveness of protein hydrolysis with pronase as a pretreament for the evaluation of furfurals generated by the Maillard reaction during toasting of cornflakes and the parallel development of brown and fluorescent compounds. Furfurals were more accurately quantified with the pronase hydrolysis pretreatment because the protein matrix binds furfurals and fluorescent compounds. For control of the early reaction steps in the toasting process, the most sensitive parameter was fluorescence. </p

On the Influence of Anti-Roll Stiffness on Vehicle Stability and Proposal of an Innovative Semi-Active Magnetorheological Fluid Anti-Roll Bar

Modern vehicles are equipped with several active and passive devices whose function is to increase active safety. This paper is focused on the anti-roll stiffness influence on vehicle handling, and follows a theoretical approach. The work firstly develops a quadricycle theoretical model, useful to study the influence of anti-roll stiffness on the vehicle local stability. The model, involving non-linear phenomena, is simplified by proper linearizations. This procedure allows local stability analysis with low computational load. At the same time, the linearized model takes into account the dynamic effects induced by load transfers through a tyre-road interaction model sensitive to the vertical load. The study is conducted considering the anti-roll stiffnesses of the two axles as parameters. The proposed model defines the relationship between the anti-roll bars stiffness and the system state. In order to realize an adaptive system able to provide a variable roll stiffness, a semi-active anti-roll bar prototype, employing magnetorheological fluid, is described. Such device gives the possibility to quickly change the roll stiffness, according to the system state, to preserve its stability

On the Influence of Anti-Roll Stiffness on Vehicle Stability and Proposal of an Innovative Semi-Active Magnetorheological Fluid Anti-Roll Bar

Modern vehicles are equipped with several active and passive devices whose function is to increase active safety. This paper is focused on the anti-roll stiffness influence on vehicle handling, and follows a theoretical approach. The work firstly develops a quadricycle theoretical model, useful to study the influence of anti-roll stiffness on the vehicle local stability. The model, involving non-linear phenomena, is simplified by proper linearizations. This procedure allows local stability analysis with low computational load. At the same time, the linearized model takes into account the dynamic effects induced by load transfers through a tyre-road interaction model sensitive to the vertical load. The study is conducted considering the anti-roll stiffnesses of the two axles as parameters. The proposed model defines the relationship between the anti-roll bars stiffness and the system state. In order to realize an adaptive system able to provide a variable roll stiffness, a semiactive anti-roll bar prototype, employing magnetorheological fluid, is described. Such device gives the possibility to quickly change the roll stiffness, according to the system state, to preserve its stability

Influence of Tyre and Vehicle Constructive Characteristics on Linear Stability of a Four Wheel Vehicle Model

The study of vehicle handling behaviour is of fundamental importance in order to improve vehicle safety, especially as concerns the loss of stability in the lateral direction resulting from unexpected lateral disturbances like side wind force, tyre pressure loss, μ-split braking due to different road pavements such as icy, wet, and dry pavement, etc. The interest for vehicle stability has been actually increasing, and consequently the study of the local stability has become a fundamental discipline in the field of vehicle dynamics, being a vehicle a strongly non linear system mainly because of tyres behaviour. The study of the driving stability of a vehicle travelling on a curve in steady state conditions is the first and most important step in order to understand the effects of perturbations inevitably occurring during vehicle motion. Such a study may have a dual application: first of all it can contribute to develop and optimize control logic of the vehicle subsystems; secondly it may be useful to identify the physical quantities affecting stability and to find out their optimal set under this point of view. At this purpose it is fundamental to dispose of suitable stability maps, which typically are constituted by curves in a phase plane delimiting zones in which the system of equations describing the vehicle dynamics admits stable and strongly attractive solutions. Outside of such zones only unstable or marginally stable solutions exist. In the recent years several ways to construct these maps have been proposed. A great number of studies in literature are mainly oriented to the development of control systems strategies aimed to improve vehicle stability and so in such papers the authors proposed methods based on vehicle and tyre models extremely simplified. Typical simplifications consist in considering a bicycle model (i.e. neglecting roll dynamics and the lateral load transfer) and/or in linearising the tyre-road interaction (i.e. underestimating saturation effects in the tyre lateral forces). No studies have been found aimed to find out which vehicle physical characteristics affect significantly its stability and the influence of their variation on stability. This paper pursues precisely this purpose and hence it is necessary to use a sufficiently detailed vehicle model allowing to take into account all the physical parameters on which investigate. The stability of a complete four wheel, two axle, vehicle model will be discussed, Pacejka magic formula will be adopted to model the pure tyre-road interaction, lateral load transfer will also be considered. Two different methods will be presented: a “mathematical” method consisting in the evaluation of the state matrix eigenvalues and a ”geometrical” method inspired to the so called “handling diagram” construction. The influence exerted on the stability zone extension in the phase plane by some vehicle parameters, such as tyre cornering stiffness and front/rear roll stiffness will be evidenced with the aim to suggest solutions able to increase vehicle stability

A Combined Use of Phase Plane and Handling Diagram Method to Study the Influence of Tyre and Vehicle Characteristics on Stability

This paper deals with in-curve vehicle lateral behaviour and is aimed to find out which vehicle physical characteristics affect significantly its stability. Two different analytical methods, one numerical (phase plane) and the other graphical (handling diagram) are discussed. The numerical model refers to the complete quadricycle, while the graphical one refers to a bicycle model. Both models take into account lateral load transfers and nonlinear Pacejka tyre–road interactions. The influence of centre of mass longitudinal position, tyre cornering stiffness and front/rear roll stiffness ratio on vehicle stability are analysed. The presented results are in good agreement with theoretical expectations about the above parameters influence, and show how some physical characteristics behave as saddle-node bifurcation parameters