Effect of Different Rice Starches, Inulin, and Soy Protein on Microstructural, Physical, and Sensory Properties of Low-Fat, Gluten, and Lactose Free White Sauces

[EN] The microstructural, physical, and sensory properties of low-fat sauces made with different rice starches, soy protein ,and inulin were analysed in order to obtain sauces suitable for celiac and lactose intolerant consumers. Soy protein and inulin could prevent starch degradation due to their high water-binding capacity. Moreover, protein molecules could diffuse into the starch granules and soluble inulin could interact with starch polymers within the granule. Both effects would hinder amylose leaching. Inulin provides better diffusion capacity of gelatinised granules and soy protein-starch granule aggregates than sunflower oil, which helps to decrease viscosity in modified rice starch sauces. Soy protein prevents synaeresis in the sauces. Inulin affects colour parameters in native rice starch sauces, probably because of inulin and retrograded amylose polymers interactions. Sauces made with sunflower oil and modified rice starch are best rated by consumers. However, according to the statistical analyses, the replacement of oil by inulin could be suitable to prepare low-fat, gluten, and lactose free white sauces when modified rice starch is used.Supported by the Universitat Politecnica de Valencia, Project No. PAID-06-09-2871, and Generalitat Valenciana, Project GV-2010/038.Guardeño Expósito, LM.; Vázquez Gutiérrez, JL.; Hernando Hernando, MI.; Quiles Chuliá, MD. (2013). Effect of Different Rice Starches, Inulin, and Soy Protein on Microstructural, Physical, and Sensory Properties of Low-Fat, Gluten, and Lactose Free White Sauces. Czech Journal of Food Sciences. 31(6):575-580. https://doi.org/10.17221/483/2012-CJFSS57558031

Microstructural, physical, and sensory impact of starch, inulin and soy protein in low-fat gluten and lactose free white sauces

[EN] The microstructural, physical, and sensory properties of low-fat sauces made with different starches, soy protein, and inulin as a fat replacer were analyzed. Gluten-free waxy starches-rice and corn-were selected as well as soy protein to obtain sauces suitable for celiac and lactose intolerant consumers. Light microscopy was used to visualize the swollen starch granules dispersed in a protein-amylopectin-inulin phase. Inulin seemed to limit protein network development, which was related with a higher dispersion of starch granules within the sauce matrix. Therefore, the sauces made with inulin had a lower apparent viscosity (¿app) values (P < 0.05) in comparison with oil sauces. The sauces made with rice starches also exhibited a lower viscosity (P < 0.05) since these granules did not swell as corn granules do. All the sauces had a remarkable physical stability since there were no syneresis phenomena and color did not change significantly (P < 0.05) after 15 d of refrigeration storage (4 °C). Finally, the sensory test suggests that oil could be substituted by inulin in the preparation of low-fat sauces since no significant differences (P < 0.05) in texture and flavor were found. These results encourage further research to optimize the formulations of these types of alternative white sauces. Practical Application: Nowadays there is a great demand of ready-to-eat products due to new consumptions habits. In this context, it would be interesting to develop low-fat sauces with inulin that could be used in this type of products improving their nutritional profile. The requirement of processed food for specific groups of population, such as celiac and lactose intolerant consumers, makes it necessary to use gluten free starches and soy protein in the formulation of sauces. The characterization of structural, physical and sensory properties is required to understand the product acceptability and its behavior during its shelf life. © 2012 Institute of Food Technologists®.The authors are grateful for the FPU grant awarded to L. M. Guardeno and the economic support received from Univ. Politecnica de Valencia-project PAID-06-09-2871 and Generalitat Valenciana-project GV-2010/038.Guardeño Expósito, LM.; Hernando Hernando, MI.; Llorca Martínez, ME.; Hernández Carrión, M.; Quiles Chuliá, MD. (2012). Microstructural, physical, and sensory impact of starch, inulin and soy protein in low-fat gluten and lactose free white sauces. Journal of Food Science. 77(8):859-865. https://doi.org/10.1111/j.1750-3841.2012.02798.xS85986577

Composition, protein contents and microstructural characterisation of grains and flours of Emmer wheats (Triticum turgidum ssp dicoccum) of the central italy type

The microstructural characteristics were evaluated of two types of Italian Farro (Triticum turgidum ssp. dicoccum) with spring and autumn growth habits, the former with a vitreous tendency and the latter with a floury tendency. Common wheat flours and grains (Triticum aestivum) were used as controls. Protein fractions such as glutenin and gliadin were extracted from Triticum turgidum ssp. dicoccum flours and studied by SDS-PAGE in order to make a comparison between the electrophoretic analyses and microstructural studies which were conducted on the same samples using Scanning Electron Microscopy (SEM and Cryo-SEM). The results obtained by SDS-PAGE showed that the gliadin patterns of both emmer samples were similar, while the common wheat gliadins showed a band at 90 kD a that was not present in the gliadin fraction of emmer. When the glutenin patterns were analysed, the autumn emmer did not show the low molecular weight protein bands (16-23 kDa) whilst spring emmer wheat appeared more similar to common wheat. Regarding the microstructural characteristics of the kernels, spring (vitreous tendency) emmer showed starch granules covered by protein to a higher extent than autumn emmer. These differences were also observed in flours. The gluten of spring emmer wheat was observed as a homogeneous structure showing similarities with common wheat gluten, while autumnal emmer gluten appeared more heterogeneous and lacking in structure.Giacintucci, V.; Guardeño Expósito, LM.; Puig Gómez, CA.; Hernando Hernando, MI.; Sacchetti, G.; Pittia, P. (2014). Composition, protein contents and microstructural characterisation of grains and flours of Emmer wheats (Triticum turgidum ssp dicoccum) of the central italy type. Czech Journal of Food Sciences. 32(2):115-121. http://hdl.handle.net/10251/64424S11512132

Effect of Microwave Thawing on Microstructure and Physicochemical Stability of Low Fat White Sauces Made with Soy Protein

[EN] The microstructural and physicochemical stability of white sauces made with soy protein and modified waxy maize starch was evaluated after subjecting them to a freezing-thawing process in a conventional or microwave oven. The microstructure of sauces revealed a structured matrix of soy protein and starch polymers where fat globules and swollen starch granules remain dispersed. Both thawing methods affected the fat globule size and morphology but they did not affect the starch granules. The SDS-PAGE analysis did not show any apparent changes between sauces thawed by both methods. Moreover, a similar pattern was found in the soy protein isolate used as a raw material indicating that this type of protein was also stable to the cooking process. There were no significant differences (P > 0.05) in the reducing power of the sauces regardless of the thawing method used. However, the acidity index and the k232 parameter were significantly higher (P < 0.05) in conventionally thawed sauces. Finally, syneresis was negligible and no significant differences (P > 0.05) were found among different frozen storage periods. In conclusion, the formulation of the sauce is appropriate to develop low fat, vegetarian meals which can be subjected to frozen storage and microwave reheatingSupport by the Ministerio de Ciencia e Innovación, Project No. AGL2006-11653-C02, and the FPU grant awarded to L.M. Guardeño.Guardeño Expósito, LM.; Quiles Chuliá, MD.; Llorca Martínez, ME.; Pertusa, J.; Hernando Hernando, MI. (2013). Effect of Microwave Thawing on Microstructure and Physicochemical Stability of Low Fat White Sauces Made with Soy Protein. Czech Journal of Food Sciences. 31(6):568-574. http://hdl.handle.net/10251/75251S56857431

Elaboración de sistemas modelo con polisacáridos para la formulación de salsas aptas para calentamiento en microondas

En el presente estudio se caracteriza la influencia de distintos polisacáridos (almidón nativo y modificado y tau, lambda y kapa carragenatos) y de la sal sobre las propiedades dieléctricas, la reología y la microestructura en sistemas modelo. El objetivo es conocer la conveniencia del uso de estos ingredientes para la futura formulación de salsas con propiedades óptimas para su calentamiento en horno microondas. Los resultados obtenidos muestran que los almidones de maíz (nativo y modificado) suministran una viscosidad adecuada a las salsas, aunque provocan una disminución significativa (p<0.05) en el factor de pérdidas lo que afecta negativamente a la eficacia del calentamiento; sin embargo, no afectan significativamente (p<0.05) a la profundidad de penetración. La disminución del factor de pérdidas se relaciona con una disminución de agua libre en el sistema, lo cual se observa por Cryo-SEM a nivel microestructural. El uso de tau, lambda y kapa carragenatos no afecta significativamente (p<0.05) al factor de pérdidas por lo que podrían usarse como espesantes en sustitución parcial de los almidones. Por otro lado, la sal es un factor significativamente positivo (p<0.05) para el factor de pérdidas y negativo para la profundidad de penetración, lo que hace necesario su uso en una cantidad adecuada para optimizar el calentamiento según el tipo de producto que se desee elaborar. La relación entre las propiedades reológicas y las propiedades dieléctricas depende del tipo de sistema. En los sistemas con almidón el aumento en la consistencia se relaciona con la disminución del agua libre y por tanto con la disminución en el factor de pérdidas. Por su parte, la influencia del carragenato y de la sal no se relaciona con las propiedades de flujo.Guardeño Expósito, LM. (2008). Elaboración de sistemas modelo con polisacáridos para la formulación de salsas aptas para calentamiento en microondas. http://hdl.handle.net/10251/13147Archivo delegad

Optimización de la formulación de una salsa apta para calentar en microondas: estudio químico y microestructural

En los últimos años se han producido cambios en los hábitos de consumo alimentario causados principalmente por un menor tiempo disponible para la preparación de las comidas y la reducción del número de personas por unidad familiar. El sector de los platos preparados se ha consolidado en el mercado, ofreciendo al consumidor productos de fácil y rápida preparación. En este contexto, el horno microondas se ha convertido en un electrodoméstico indispensable en cada hogar por su facilidad de uso y rapidez en la preparación de este tipo de productos. Las peculiaridades del calentamiento por microondas, donde la composición del propio alimento influye de manera crucial, dificulta la predicción generalizada del patrón de calentamiento en alimentos y hace necesario un estudio individualizado para cada caso en particular. Por tanto, la tendencia actual consiste en diseñar alimentos que sean aptos para el calentamiento en microondas desde la propia formulación de los mismos. En la presente tesis doctoral se estudiaron sistemas modelo tipo salsa bechamel como ejemplo de producto elaborado que se comercializa por sí solo o formando parte de platos preparados. Inicialmente, se analizó el impacto de la formulación de sistemas modelo elaborados con sal, agua y distintos hidrocoloides (almidones y carragenatos) en las propiedades intrínsecas del calentamiento en microondas (propiedades dieléctricas) y en las propiedades reológicas y microestructurales. A continuación, se analizaron las propiedades microestructurales y reológicas de salsas elaboradas con diversos almidones (nativos y modificados) con el fin de observar el comportamiento frente al calentamiento en horno microondas. Además, se analizó la estabilidad química y microestructural de salsas formuladas con diferentes proteínas (láctea o de soja) frente a un proceso de congelación-descongelación en horno microondas o convencional. Por último, se analizaron la microestructura y las propiedades dieléctricas de salsas elaboradas con diferentes grasas preparadas a diferentes velocidades de agitación.Guardeño Expósito, LM. (2012). Optimización de la formulación de una salsa apta para calentar en microondas: estudio químico y microestructural [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/15758Palanci

Microwave heating effect on rheology and microstructure of white sauces

[EN] The microstructure and rheological properties of white sauces formulated with different starches were analyzed after being microwave-heated for different times. Significant differences (P < 0.05) in rheological parameters analyzed-storage modulus (G'), loss modulus (G¿), and loss tangent (tan¿)-were obtained for sauces made with different starches. Microwave reheating did not affect G' and G¿ values until water evaporation became significant. In addition, tan¿ values did not change significantly (P < 0.05) even during long reheating times showing that sauce viscoelastic properties did not change after microwave irradiation. However, microstructure assessed by confocal laser scanning microscopy showed changes in fat globule and protein. These microstructural changes did not seem to have a significant effect on rheological measurements since starch and ¿-carrageenan are mainly responsible for the viscoelastic behavior of the sauces. Practical Application: The development of products appropriate to microwave heating is constantly rising in food industry. It is necessary to understand the behavior of the ingredients and the final product to microwave heating in order to choose those ingredients which will develop the best performance. Starches are common ingredients in industrial sauces, and rheological and microstructural techniques have shown their usefulness in characterization of starch-based systems. © 2011 Institute of Food Technologists ®.The authors are grateful for the economic support (project AGL2006-11653-C01 and C02) received from the Ministerio de Ciencia e Innovacion and the FPU grant awarded to L.M. Guardeno.Guardeño Expósito, LM.; Sanz, T.; Fiszman, S.; Quiles Chuliá, MD.; Hernando Hernando, MI. (2011). Microwave heating effect on rheology and microstructure of white sauces. Journal of Food Science. 76(8):544-552. https://doi.org/10.1111/j.1750-3841.2011.02339.xS54455276

Structural stability of white sauces prepared with different types of fats and thawed in a microwave oven

This paper describes the microstructure and dielectric properties of white sauces prepared with different fats (sunflower oil, olive oil, soy oil, and butter) and agitation speeds (350, 1100 and 3250 rpm). The structural stability of sauces during thawing using conventional oven (CO) and microwave oven (MO) are studied. The results showed that, for fresh samples (not subjected to the freeze-thaw cycle) an increase in agitation speed during elaboration from 350 to 1100 rpm caused a significant decrease (p 0.05) affect fat globule size and shape, regardless of the agitation speed and type of fat. Sauces that were stable during the freeze-thaw cycle were obtained using speeds of 1100 and 3250 rpm. © 2011 Elsevier Ltd. All rights reserved.The authors are grateful for the economic support (project AGL2006-11653-C02) received from the Spanish Ministry of Science and Innovation.Hernández Carrión, M.; Guardeño Expósito, LM.; Carot, JM.; Perez Munuera, I.; Quiles Chuliá, MD.; Hernando Hernando, MI. (2011). Structural stability of white sauces prepared with different types of fats and thawed in a microwave oven. Journal of Food Engineering. 104(4):557-564. https://doi.org/10.1016/j.jfoodeng.2011.01.017S557564104

Dielectrical, microstructural and flow properties of sauce model systems based on starch, gums and salt

The dielectric properties of salted systems based on different hydrocolloids (native or modified starches, or on iota, lambda, or kappa carrageenan) as models for microwaveable white sauces were studied. Microstructural and rheological properties were also studied to better understand the dielectric behaviour. As expected, salt had a significantly positive effect (p < 0.05) on both dielectric properties. Raising the starch concentration significantly lowered (p < 0.05) the loss factor, whereas increasing the carrageenan did not. None of the hydrocolloids significantly affected the penetration depth. The decrease in the loss factor could be related to a decrease in the free water content which was observed by Cryo-SEM. Free water and salt content seemed to be the major factors to control for microwave heating of hydrocolloid-thickened systems. (C) 2009 Elsevier Ltd. All rights reserved.The authors are grateful for the economic support (project AGL2006-11653-C01 and C02) received from the Ministerio de Ciencia e Innovacion and the grant awarded to L.M. Guardeno. The authors also appreciate lecturer J.M. Carot's help in the statistical treatment of data, the R&D&D&I Linguistic Assistance Office, Universidad Politecnica de Valencia (Spain), for translating this paper and Mary Georgina Hardinge for copy editing.Guardeño Expósito, LM.; Catalá Civera, JM.; Plaza González, PJ.; Sanz, T.; Salvador, A.; Fiszman, S.; Hernando Hernando, MI. (2010). Dielectrical, microstructural and flow properties of sauce model systems based on starch, gums and salt. Journal of Food Engineering. 98(1):34-43. https://doi.org/10.1016/j.jfoodeng.2009.12.004S344398