Hugo Diego Sánchez

Use of Response Surface Methodology to Optimize Gluten-Free Bread Fortified with Soy Flour and Dry Milk

The percentages of soy flour (X1) and dry milk (X2) were varied for the production of gluten-free bread to optimize batter softness (Y1), specific volume (Y2), crumb grain score (Y3), bread score (Y4) and bread protein content (Y5). A central composite design was used and second-order models for Y1 were employed to generate response surfaces. When bread protein content was decreased from 10 to 3%, specific volume increased from 3.2 to 4.6 cm3/g and bread score increased too. Nevertheless, the highest crumb grain score was obtained at 7.3% of bread protein content. The results demonstrated that a gluten-free bread can be prepared by adding 7.5% soy flour and 7.8% dry milk to a previously developed formulation, increasing its protein content from 1 to 7.3% and modifying in a small degree, its sensory quality.

Use of sodium stearoyl lactylate and azodicarbonamide in wheat flour breads with added pea flour

Different amounts of sodium stearoyl lactylate (SSL) (X1) and azodicarbonamide (ADA) (X2) were analyzed to measure their effect on breadmaking using wheat flour with incorporation of pea flour (Pisum sativum) to the dough. The objective of the present work was to optimize the physical properties of dough (Y1Y2Y3Y4), the dough consistency during mixing (Y5Y6) and the baking performance (Y7Y8Y9). A central composite design and second-order models for Yi were employed. For dough physical properties and dough consistency during mixing, the best response was found when SSL varied between 0.5 and 1.5% and ADA between 110 and 170 ppm. For responses concerning the baking performance, better values for specific volume, crumb texture scores and bread score were obtained using SSL between 0.9 and 1.4% and ADA between 50 and 80 ppm. It is concluded that for baking with wheat flour replaced at about 10% with inactivated pea flour it should be advised to use SSL at levels close to 1% with ADA between 50 and 80 ppm.

Effect of dough water content and mixing conditions on energy imparted to dough and bread quality

This study explores the influence of water content, mixing speed, and mixing time on energy imparted to dough and on specific volumes and bake scores of the resulting pan breads made with flours of different qualities. Responses measured were dough work input (Y 1 ), specific volume of bread (Y 2 ), and bake score (Y 3 ) while the variables chosen were water added (X 1 ), mixing speed (X 2 ), and mixing time (X 3 ). Water added ranged between 59.7 and 62.7 %, mixing speed between 20 and 100 rpm, and mixing time between 2 and 12 min. Dough work input was strongly correlated with all variables chosen for this study, while specific volume and bake score had only a high statistical significance with respect to mixing speed (X 2 ) and mixing time (X 3 ). The maximum value for Y 2 (5.2 cm/g) resulted when X 2 = 90 rpm and X 3 = 8 min. This indicates that better products are obtained with 720 mixer blade revolutions; this is a critical factor for optimal dough development and then for obtaining a good crumb grain. Finally, bread quality can be improved by increasing mixer blade revolutions up to values in the range of 700–800, corresponding to a dough work input of ~40 kJ/kg. level that varies with both flour and mixer; and the work imparted to the dough must be greater than a minimum critical amount that is dependent on the flour used (2). During processing, every breadmaking step significantly affects product quality (11). Several measurements have been used to measure rheological properties of wheat dough; such measurements must be sensitive to dough water content, since optimal mechanical properties result from an optimum flour-to-water ratio (3). Small-scale laboratory mixers are widely used to predict dough-mixing behavior on an industrial scale. Two traditional instruments for testing wheat dough are the farinograph and the mixograph, which mix flour and water by shear and extensional deformation and form developed dough (10). If laboratory-scale mixers are to be used to predict industrial-scale mixing behavior, their mixing mechanism must be similar to that of industrial-scale mixers (18). In Argentina, industrial-scale pan bread is produced mainly by mechanical dough development, which uses high-speed mixing and an oxidizing agent. Response surface methodology (RSM) is a statistical technique used to optimize processes or formulations, using minimal experimental trials, when many factors and interactions may be involved (12). RSM uses a central composite design to fit a model using least-squares analysis. The adequacy of a proposed model is revealed by diagnostic checking provided by analysis of variance (ANOVA) and residual plots. Contour plots are useful to study RSM data and determine optimal conditions (16). This study explores the influence of water content, mixing speed, and mixing time on energy imparted to dough and on specific volumes and bake scores of the resulting pan breads made with flours of different qualities. RESEARCH Table I. Gluten content, damaged starch, and rheological characteristics of samples

Effect of Xylanase on the Technological Behaviour of Wheat Flours

Fil: Osella, C.. Universidad Nacional del Litoral. Facultad de Ingenieria Quimica. Instituto de Tecnologia de Los Alimentos; Argentina

Efecto de Oxidantes y Emulsionantes sobre la Calidad del Pan elaborado con incorporación de Harina de Arvejas (Pisum sativum) inactivadas Enzimáticamente

The effect of oxidants and emulsifiers on the quality of bread made with the addition of inactivated pea flour was studied. Specific volume determination and sensory evaluation were carried out. Statistical tools were Analysis of Variance (ANOVA) and Duncans Multiple Range Test. The replacement of 10% of wheat flour by pea flour was selected as equilibrium between nutritional improvement and technological deterioration. Azodicarbonamide gave better results than those obtained with ascorbic acid. Sodium stearoyl lactylate had better technological performance compared to the diacetyltartaric monoglyceride. It is concluded that with 10% pea flour the chemical score increased by 22.4% in chemical score.

Molienda de Trigo: Ensayos Comparativos de Escala Industrial con Planta Piloto

El objetivo del presente trabajo fue evaluar el potencial de la molienda experimental de planta piloto para la produccion de harinas con caracteristicas similares a las obtenidas en el proceso industrial. Se analizaron los aspectos fisicos, quimicos y tecnologicos de harinas provenientes de distintos trigos, producidas por dos molinos experimentales y por uno industrial. Las evaluaciones de las harinas fueron realizadas por triplicado y analizadas estadisticamente por el test de rango multiple de Duncan. Se encontraron diferencias en los valores amilograficos, farinograficos y en la composicion quimica de las harinas. Las caracteristicas alveograficas y el comportamiento tecnologico mostraron diferencias no significativas (a=0.05). Se concluye que los diagramas propuestos en la molienda experimental pueden ser utilizados para predecir el comportamiento del trigo en la molienda industrial.