Desarrollo de una biopelícula activa, que aumente la vida de anaquel en carne de bovino

Tesis de DoctoradoLa carne es esencial en la alimentación humana por su calidad nutrimental. Sin embargo, es un producto degradable por oxígeno y microorganismos, los cuales, ponen en riesgo la calidad e inocuidad del alimento. De ahí la importancia de ocupar empaques plásticos que muestren y protejan éste tipo de productos. Sin embargo, los convencionales son altamente contaminantes por su baja degradación. Por ello en la actualidad se han desarrollado las denominadas biopelículas activas de fácil degradación y que confieren actividad antimicrobiana y antioxidante. Así, el objetivo de la investigación es desarrollar y caracterizar una biopelícula activa con desechos agroindustriales, que mejore las características fisicoquímicas y de inocuidad en la vida útil de carne bovina. Para ello se usó un diseño experimental factorial 3x3 entre tres concentraciones (etanol:agua 20:80, 50:50, 80:20 v/v) y tres residuos (hojas: guayaba aguacate y ciruelo). El resultado indicó que las mayores concentraciones las presentó la interacción 50:50 v/v (etanol/agua) con la hoja de guayaba (fenoles totales=111.78.8 mg GAE/g MS, saponinas =88.56.92 mg/g MS y Actividad antioxidante=450.318 μM TEAC/g MS). Posteriormente, se realizaron pruebas de capacidad antimicrobiana, donde solamente muestra inhibición el extracto de hojas de guayaba en contra de 8 microorganimos patógenos evaluados mostrando una capacidad mínima inhibitoria en un rango 0.62-1.25 mg/ml. Con estos resultados se realizaron biopelículas (Gelatina-quitosano) con y sin extracto de guayaba, las cuales fueron caracterizadas midiendo propiedades ópticas y mecánicas, VII permeabilidad, así como su morfología y propiedades térmicas. Encontrando como resultado que ambas muestran en general buenas propiedades plásticas., en cuanto al efecto que causo la adición del extracto se observan que no efecto las propiedades de grosor, elongación, módulo de Young, permeabilidad al vapor de agua y al oxígeno, así como la morfología, ni sus propiedades térmicas como TGA y DSC., ya que se muestran similares a las biopelículas sin extracto, En contraparte a esto la adición del extracto si mostro diferencia significativa (P<0.05) en resistencia a la tensión, donde se observa una diminución en este valor, así como un efecto visible en las imágenes SEM de la presencia y distribución homogénea de las micelas del extracto y las cuales se sugieren le brindan a las biopelículas un efecto benéfico bioactivo en la vida útil de carne bovina manteniendo la inocuidad y características fisicoquímica de la carne por un lapso mayor de tiempo.UAEMe

Ethanol and aqueous extracts characterization from guava (Psidium guajava L.) and avocado (Persea americana Mill.) residues

Artículo científicoIn Mexico, avocado and guava production generate agronomic residues that contain bioactive compounds as secondary metabolites produced in plants. Their consumption offer favourable health effects; therefore, the objective of the present research was to characterize the bioactive compounds and antioxidant properties in guava (Psidium guajava L.) and avocado (Persea americana Mill.) residues (pulp or epicarp and leaves) at different ethanol concentrations (T1 100%, T2 75%, T3 50% and T4 25%, v/v) and in aqueous extracts (T5). Avocado epicarp (56.17 mg of EAG g-1 dm) and guava leaves 50% extracts (45.13 mg of EAG g-1 dm) presented the highest total phenol content; consequently, as it was expected avocado epicarp (328.95 TEAC/g dm) and guava leaves 25% extracts (320.01 TEAC/g dm) shown the highest antioxidant capacity. On the other hand, the highest saponins values were at avocado (100.60 mg g-1 dm) and guava leaves (76.96 mg g-1 dm) 25% extracts. Then avocado epicarp and guava leaves extracts are suggested as a high potential for agro-industrial, pharmacological and chemical uses.UAEMe

Evaluación de la calidad fisicoquímica y bromatológica para la producción de trigos panaderos

Wheat is one of the most important protein sources for human beings. Several food products are elaborated from this cereal, such as bread. Mexican wheat breeding programs are focused on to identify those genotypes with high yields and bread quality. Therefore, the aim of this study was to evaluate the environmental effects over the Physicochemical and Bromatological quality parameters of Cal Blanco F2011, Matchett F2011 and RSM-Norman F2008 wheats sown at the experimental fields at Mexicali, Baja California, Querendaro, Michoacán and Tarimoro, Guanajuato, Mexico during the autumn-winter growing cycle for two consecutive years (2014-2016) under irrigation conditions. Grain Hectolitric weight (GHW); Weight of 1,000 grains (WTG), Grain Length, Width and Thickness; Flour Colour (L, a* and b*), the Percentages of Protein, Starch and Ashes, and Zeleny sedimentation tests (IZ) were determined. Wheat genotypes showed significant differences in most of the study variables and all the values were related to good bakery quality. GHW, WTG and most of the physicochemical quality values were strongly affected by the environmental factors over the genotype. The three genotypes showed acceptable ZI values, especially RSM-Norman F2008 grains from all the localities studied. Finally, these genotypes presented suitable Physicochemical and Bromatological qualities, and are recommended for irrigation conditions.This research was funded by the project “Molecular studies research project for quality of bread wheat genotypes (Triticum aestivum L.) grown in the state of Mexico” from Support Programme for incorporating new full-time teachers by PRODEP, SEP

Physicochemical and bromatological quality evaluation for bread wheat production

Wheat is one of the most important protein sources for human beings. Several food products are elaborated from this cereal, such as bread. Mexican wheat breeding programs are focused on to identify those genotypes with high yields and bread quality. Therefore, the aim of this study was to evaluate the environmental effects over the Physicochemical and Bromatological quality parameters of Cal Blanco F2011, Matchett F2011 and RSM-Norman F2008 wheats sown at the experimental fields at Mexicali, Baja California, Querendaro, Michoacán and Tarimoro, Guanajuato, Mexico during the autumn-winter growing cycle for two consecutive years (2014-2016) under irrigation conditions. Grain Hectolitric weight (GHW); Weight of 1,000 grains (WTG), Grain Length, Width and Thickness; Flour Colour (L, a* and b*), the Percentages of Protein, Starch and Ashes, and Zeleny sedimentation tests (IZ) were determined. Wheat genotypes showed significant differences in most of the study variables and all the values were related to good bakery quality. GHW, WTG and most of the physicochemical quality values were strongly affected by the environmental factors over the genotype. The three genotypes showed acceptable ZI values, especially RSM-Norman F2008 grains from all the localities studied. Finally, these genotypes presented suitable Physicochemical and Bromatological qualities, and are recommended for irrigation conditions.This research was funded by the project “Molecular studies research project for quality of bread wheat genotypes (Triticum aestivum L.) grown in the state of Mexico” from Support Programme for incorporating new full-time teachers by PRODEP, SEP