Abstract In Mexico, pigmented creole corn varieties are used for its consumption in a great diversity of foods. Purple corn has a high content of phytochemicals (health promoters). The extrusion process improved the accessibility of these phytochemicals. The aim of this work was to evaluate the effect of extrusion factors on the nutraceutical and functional properties of nixtamalized purple corn flour, and determine the optimal process conditions that allows obtaining a flour with the best characteristics to be used in the preparation of a beverage. The processing factors were temperature (T = 50-170 °C) and screw speed (SS = 50-240 rpm). The properties evaluated were total phenolic compounds (TPC), total anthocyanins (TA) antioxidant activity (AOX), and water solubility index (WSI). The optimization was carried out using the response surface methodology. The optimization yielded the following values: AOX: 676.34 µmol ET/100 g, TPC: 299.61 mg EGA/100 g, TA: 29.9 mg EC3G/100 g and WSI: 6.31%, under process conditions T = 50 °C and SS = 50 rpm. It was demonstrated that it is possible to generate a flour with the use of pigmented corn native to the state of Guerrero, with suitable properties for developed new corn based products.

Resumen: Los Agaves son nativos de América y tienen diferentes usos, entre los que destacan la obtención de fibras y elaboración de bebidas alcohólicas; esto ha ocasionado una considerable disminución en las poblaciones silvestres; por lo que, el objetivo fue caracterizar morfológicamente cápsulas y semillas, y evaluar el desarrollo de la plántula de maguey sacatoro (Agave angustifolia Haw.) colectadas en diferentes sitios del centro y norte del estado de Guerrero, México, para su propagación por semilla. Para el análisis morfométrico se empleó un diseño de un solo factor (Localidad) y para las variables de calidad de semilla, un análisis bifactorial (localidad y tiempo de inmersión). Los resultados obtenidos se sometieron a análisis de varianza y pruebas de medias (Tukey, p ≤ 0.05). Se tomaron peso, altura y ancho de las cápsulas y semillas. Se realizó la prueba de germinación estándar y la viabilidad con la prueba del tetrazolio. Posteriormente, se evaluó el desarrollo de plántula; en tres tiempos de inmersión en agua (0, 24 y 48 h) y se realizaron mediciones en raíz, hoja y tallo. Motuapa presentó cápsulas con mayor número de semillas y semillas normales (241 y 140, respectivamente). Las cápsulas de mayor longitud la presentaron Atetetla, Motuapa y los Amates (5.37 ± 0.50, 5.10 ± 0.40 y 4.97 ± 0.36 cm, respectivamente), Ateteta tuvo mayor ancho de cápsula (2.63 ± 0.05 cm), germinación (95%) y viabilidad (89.4%). Por lo que, La producción de plántula de A. sacatoro, mediante el uso de semillas puede ser una alternativa viable.

Abstract: Agaves are native to America and have different uses, among which the obtaining of fibers and the elaboration of alcoholic beverages stand out; This has caused a considerable decline in wild populations; Therefore, the objective was to morphologically characterize capsules and seeds, and evaluate the development of the maguey sacatoro (Agave angustifolia Haw.) seedling collected in different sites in the center and north of the state of Guerrero, Mexico, for their propagation by seed. For the morphometric analysis a single factor design (Locality) was used and for the seed quality variables, a bifactorial analysis (locality and immersion time). The results obtained were subjected to analysis of variance and tests of means (Tukey, p ≤ 0.05). Weight, height and width of the capsules and seeds were taken. The standard germination test and viability were performed with the tetrazolium test. Subsequently, the seedling development was evaluated; in three times of immersion in water (0, 24 and 48 h) and measurements were made in root, leaf and stem. Motuapa presented capsules with a higher number of seeds and normal seeds (241 and 140, respectively). The longest capsules were presented by Atetetla, Motuapa and Los Amates (5.37 ± 0.50, 5.10 ± 0.40 and 4.97 ± 0.36 cm, respectively), Ateteta had greater capsule width (2.63 ± 0.05 cm), germination (95%) and viability (89.4%). Therefore, the production of A. sacatoro seedling, through the use of seeds, can be a viable alternative.

Abstract Corn (Zea mays) is the most consumed cereal in México, so it is necessary to know the nutritional and anatomical quality of the grains, which have been the main conservation and consumption criteria of the prehispanic peoples. This practice has allowed to preserve varieties of Creole corn, however, due to the lack of knowledge of these characteristics the cultivation of these maize has been reduced, presenting a high risk of disappearing. The objective was to determine the physical, nutritive and functional quality of four varieties of creole corn: Purple-Olotillo, Dos-Puntas, Toro and Olotillo. Toro presented the highest values of width and thickness (10.79 and 7.71 mm). The Toro showed better values of Endosperm and Pericarp (84.25% and 4.01%), Dos-Puntas and Olotillo showed higher values of Germ (10.75%) and Pericarp (6.2%), respectively. The Toro had a higher content of Carbohydrates and Proteins (74.47 and 10.61%). In WSI, the best value was obtained by Dos-Puntas (11.91%) and WAI the Olotillo (245.56 g H2O/g sample). It is concluded that the Toro has better nutritional content and larger and weight grains, while the Olotillo presented the highest values of WAI, it can confer better technological properties for food processing.

Abstract In the tropics of Mexico, grasslands are the basis for feeding ruminants. The objective of the study was to determine the density, rate of appearance, death and survival of the population of stems of the Llanero grass (Andropogon gayanus Kunt) harvested at different regrowth ages (EA: 7.14, 21, 28, 35, 42 , 49 and 56 d), in two growth periods, dry season with irrigation and rainy season. The EA (treatments) were assigned to four experimental units of 3 m2, using a randomized complete block design, with four replications. In both growth periods, the stem density increased until the 28 days of regrowth later, decreased until the end of the study with greater intensity during the dry period with irrigation compared to the rainy season (325 and 378 stems m-2, respectively). There was greater appearance and death of stems in the dry period with irrigation (97 stems 100 stems-1 week-1). The population stability index was greater or close to one during the irrigated drought, while, in rains from the 42 days of regrowth, this was less than one. In conclusion, it was obtained that regrowth ages from 7 to 28 days do not compromise the population stability of stems and favor the persistence of the grasslands. Older regrowth ages during the rains do not allow to recover the stem population, which favors population instability.

Resumen En trópico de México las praderas con pastos constituyen la base de la alimentación de los rumiantes. El objetivo del estudio fue determinar la densidad, tasa de aparición, muerte y la sobrevivencia de la población de tallos del pasto Llanero (Andropogon gayanus Kunt) cosechado a diferentes edades de rebrote (ER: 7,14, 21, 28, 35, 42, 49 y 56 d), en dos periodos de crecimiento, época de sequía con riego y época de lluvias. Las ER (tratamientos) se asignaron a cuatro unidades experimentales de 3 m2, mediante un diseño de bloques completos al azar, con cuatro repeticiones. En ambos periodos de crecimiento, la densidad de tallos se incrementó hasta los 28 días de rebrote posteriormente, disminuyó hasta el final del estudio con mayor intensidad durante el periodo de sequía con riego respecto al de lluvias (325 y 378 tallos m-2, respectivamente). Hubo mayor aparición y muerte de tallos en el periodo de sequía con riego (97 a 100 tallos semana-1). El índice de estabilidad de la población fue mayor o próximo de uno durante la sequía con riego, mientras que, en lluvias a partir de los 42 días de rebrote, este fue menor que uno. En conclusión, se obtuvo que edades de rebrote de 7 a 28 días no se compromete la estabilidad poblacional de tallos y favorece la persistencia de las praderas. Mayores edades de rebrote durante las lluvias no permiten recuperar la población de tallos, lo que propicia inestabilidad de la población.

Abstract Corn (Zea mays L.) is the most consumed cereal in México and Latin America, it is important to know the physical quality of the cob and grain to obtain data that serve as a basis for the selection of the best varieties and with it contribute to the conservation and improvement of local varieties, which since the introduction of improved seeds have been at risk of disappearance due to their low yield and poor use. In the spring-summer cycle of 2018, in the town of Cruz Grande municipality of Florencio Villarreal, Guerrero. An experiment was established under a completely randomized block design. The objective was to determine the physical quality of grains and cobs of two genotypes of pigmented corn (red and yellow) belonging to the Dos Puntas variety. The quality of the cob and seed anatomy was evaluated. The results showed that there were no statistical differences between varieties; the grain with the best endosperm is yellow (80.82%) and germ is purple (11.61%); as well as, the yellow variety has a larger grain size (length 10.09 and width 4.31 mm). It is concluded that the corn with the best characteristics for sale as whole grain and use in the dough and tortilla industry, is yellow, and purple for oil extraction.

Resumen El maíz (Zea mays L.) es el cereal de más consumo en México y Latinoamérica, es importante conocer la calidad física de la mazorca y de grano a fin de obtener datos que sirvan como base para la selección de las mejores variedades y con ello contribuir a la conservación y mejora de variedades locales, que desde la introducción de semillas mejoradas se han visto en riesgo de desaparición por su bajo rendimiento y poco aprovechamiento. En el ciclo primavera-verano de 2018, en la localidad de Cruz Grande municipio de Florencio Villarreal, Guerrero. se estableció un experimento bajo un diseño en bloques completamente al azar. El objetivo fue determinar la calidad física de granos y mazorcas de dos genotipos de maíz pigmentado (rojo y amarillo) perteneciente a la variedad Dos Puntas. Se evaluó la calidad de la mazorca y anatomía de semillas. Los resultados mostraron que no hubo diferencias estadísticas entre variedades, el grano con mejor endospermo es el amarillo (80.82%) y germen es el morado (11.61%) así como, la variedad amarilla presenta un mayor tamaño de grano (largo 10.09 y ancho 4.31 mm). Se concluye que el maíz con las mejores características para venta como grano entero y para la utilización en la industria de la masa y tortilla, es el amarillo y el morado para extracción de aceite.

Abstract In Mexico, nanche grows as a shrub in a dry tropic and as a tree in humid tropics; it produces fruits with acceptance in the market, where it is increasingly popular. The objective of this research was to study the physical and chemical quality properties of the fruit and the characteristics of the endocarp and embryo of the nanche (Byrsonima crassifolia (L.) H. B. K) collected in the state of Oaxaca, Mexico. The research was conducted in the Seed Analysis Laboratory of the Graduate College, Campus Montecillo. Four repetitions of one hundred fruits, endocarps and embryos were evaluated. The analysis of measures of central tendency indicated that the fruits are in the form of an oblate, have white cream mesocarp, yellow epicarp and characteristic flavor to the species. The fruit has an endocarp with cavities for three embryos, but one or two develop, the endocarp is woody, dark brown, elliptical in shape and an accumulated limb, with sinuous grooves. The embryo is white, oval, with spirally wound cotyledons, covered with a thin brown tegument. Without endosperm There was variation in morphological and quality characters.

Resumen En México, el nanche crece como arbusto en trópico seco y como árbol en zonas de trópico húmedo; produce frutos con aceptación en el mercado, donde cada vez alcanza mayor popularidad. El objetivo de esta investigación fue estudiar las propiedades de calidad físicas y químicas del fruto y las características del endocarpio y embrión del nanche (Byrsonima crassifolia (L.) H. B. K.) colectados en el estado de Oaxaca, México. La investigación se realizó en el Laboratorio de Análisis de Semillas del Colegio de Postgraduados, Campus Montecillo. Se evaluaron cuatro repeticiones de cien frutos, endocarpios y embriones. El análisis de medidas de tendencia central indicó que los frutos tienen forma de oblato, presentan mesocarpio blanco a crema, epicarpio amarillo y sabor característico a la especie. El fruto tiene un endocarpio con cavidades para tres embriones, pero uno o dos se desarrollan, el endocarpio es leñoso, color café oscuro, de forma elíptica y una extremidad acuminada, con surcos sinuosos. El embrión es blanco, ovalado, con cotiledones enrollados en forma de espiral, cubiertos con un tegumento delgado color café. Sin endospermo. Hubo variación en caracteres morfológicos y de calidad.