Effect of maize processing on amylose-lipid complex in pozole, a traditional Mexican dish

One of the most traditional foods in Mexico is pozole (a soup of maize grains with pork). Maize starch interacts with fatty acids during its preparation, generating amylose-lipid complexes. This study aimed to determine the effect of lard concentration on the formation of amylose-lipid complexes and their effect on the physicochemical properties of the starch after pozole preparation. Three maize varieties were nixtamalized and cooked, using 0, 6, 8, and 10 % lard. Grain physical parameters, viscosity, resistant starch, and detailed characterization of starch granules were analyzed. X-ray diffraction patterns showed structural damage in the crystalline starch structure. Two of the maize varieties showed an amylose-lipid endotherm with the addition of lard. The viscosity profile was affected by grain hardness and heat treatment, whereas lard addition decreased the viscosity of samples. The addition of higher percentages of lard (8 and 10%) favors the formation of amylose-lipid complexes, as shown in thermal properties and resistant starch

Conservation and Use of Latin American Maize Diversity: Pillar of Nutrition Security and Cultural Heritage of Humanity

Latin America is the center of domestication and diversity of maize, the second most cultivated crop worldwide. In this region, maize landraces are fundamental for food security, livelihoods, and culture. Nevertheless, genetic erosion (i.e., the loss of genetic diversity and variation in a crop) threatens the continued cultivation and in situ conservation of landrace diversity that is crucial to climate change adaptation and diverse uses of maize. We provide an overview of maize diversity in Latin America before discussing factors associated with persistence of large in situ maize diversity, causes for maize landrace abandonment by farmers, and strategies to enhance the cultivation of landraces. Among other factors, maize diversity is linked with: (1) small-holder farming, (2) the production of traditional food products, (3) traditional cropping systems, (4) cultivation in marginal areas, and (5) retention of control over the production system by the farmers. On the other hand, genetic erosion is associated with substitution of landraces with hybrid varieties or cash crops, and partial (off-farm labor) or complete migration to urban areas. Continued cultivation, and therefore on-farm conservation of genetic diversity held in maize landraces, can be encouraged by creating or strengthening market opportunities that make the cultivation of landraces and open pollinated varieties (OPVs) more profitable for farmers, supporting breeding programs that prioritize improvement of landraces and their special traits, and increasing the access to quality germplasm of landraces and landrace-derived OPVs

Utilization of heterotic patterns within Corn Belt germplasm for adapting, grouping and selecting exotic maize populations

This research was conducted with the objectives of determining: (i) potential use of Reid Yellow Dent-Lancaster Sure Crop heterotic pattern (RYD-LSC H-P) in the incorporation of exotic germplasm into Corn-Belt germplasm, (ii) potential use of RYD-LSC H-P in grouping germplasm which has undefined H-P, and (iii) potential use of progeny derived from exotic x adapted populations based on agronomic and grain quality performance. Adaptation over five years of random mating and mild selection of four adapted x exotic populations (NCMT populations) is described. NCMT populations were formed on basis of genetic background, breadth of genetic base, and RYD-LSC H-P. Populations NCMT1 and NCMT2 were defined respectively as narrow and broad genetic base, while NCMT3 and NCMT4 were defined as LSC and RYD types. Selection of full-sib and S\sb1 progeny was based on data obtained during summer of 1990, at Lincoln and Mead, NE. The top 60 lines from each population were crossed to FR36 and FR1075, which represent both sides of the RYD-LSC H-P. During summer of 1991 test-crosses from each population were evaluated at York and Lincoln, NE. S\sb3 lines per se were evaluated at Lincoln the same year. Results indicated that H-P involved in the formation of populations NCMT3 and NCMT4 was maintained through five cycles of adaptation. Results also support use of H-P for incorporation of exotic into adapted material. Potential for grouping genotypes with undefined H-P was shown in NCMT1 and NCMT2, where approximately 50% of the lines were grouped on each side of the H-P. Proportion of lines of NCMT3 (LSC) and NCMT4 (RYD) was approximately 70% into the expected heterotic side. Favorable adaptation was observed in all NCMT populations, where some test-crosses outyielded B73 x Mo17 and exhibited similar or superior agronomic characteristics. S\sb3 lines from NCMT populations also exhibited competitive grain yield and agronomic characteristics compared to inbreds FR36 and FR1075. Additionally, samples from test-crosses of each population had superior grain quality as compared to B73 x Mo17

Generación de maíces especializados para mejorar la salud y nutrición en México

Due to the great maize genetic diversity, over the time selection have been practiced to obtain textures, flavors, aromas for specific uses. At present, this selection is still valid by farmers and also by researchers who take advantage of new technological advances to efficiently assist selection, and to identify maize with specific characteristics, so it is possible “to tailored” bio-fortified, specialty and quality maize varieties according to the main forms of uses, consumption, and exploitation, that provide greater value added, and that allow the development of bio-active compounds and functional foods. Likewise, for the selection of maize with greater digestibility that impact and make more efficient livestock production. The interdisciplinary interaction between maize breeding programs with researcher groups specialized in disciplines related to food technology, can generate bio-fortified specialty maize which contain bio-active and nutraceutical compounds. INIFAP's maize program at Bajío region in Mexico, has implemented strategies to generate improved bio-fortified, bio-active and functional maize varieties, which have an impact on the health and nutrition of consumers. With a view to influencing the strategies described above, emphasis has been placed on maize germplasm development, focused on implementing research lines to generate: high oil content maize; white kernel maize with nixtamalera-tortillera quality; yellow kernel maize; high-quality protein maize (QPM); pigmented (such blue maize); popcorn; forage quality; fusarium and Aflatoxin contamination resistance; among others. This paper presents the advances and achievements obtained in these research lines. Based on the presented information, it is possible to say that we are at the forefront of great challenges and opportunities in interdisciplinary maize research in Latin America. That will allow us to develop genetic materials that, in addition to face imminent production risks, we can select specialty bio-fortified maize varieties, with value added, which allow the development of bio-active components, functional foods and also development of new industrial products.Gracias a la gran diversidad genética de maíz existente, a través del tiempo se ha practicado selección hacia maíces con texturas, sabores, aromas y usos específicos. En la actualidad, esta selección sigue siendo vigente tanto por los productores, como por los investigadores quienes aprovechan los avances tecnológicos para asistir la selección de manera eficiente, e identificar maíces con características específicas, por lo que es posible  “confeccionar” maíces bio-fortificados, especializados y con calidad de acuerdo a las principales formas de consumo, utilización y aprovechamiento; que aporten mayor valor agregado y que permitan desarrollar componentes bio-activos y alimentos funcionales. Así mismo para la selección de maíces con mayor digestibilidad que impacten y hagan más eficiente la producción pecuaria. La interacción interdisciplinaria de los programas de mejoramiento genético de maíz con grupos de investigación especialistas en disciplinas relacionadas con la tecnología de alimentos, pueden generar maíces especializados y bio-fortificados que contengan compuestos bio-activos, y nutraceuticos. El programa de maíz del INIFAP, en la región del Bajío, en México, ha implementado diversas estrategias para: a) generar maíces mejorados que incrementen la producción y reduzcan costos de cultivo que incrementar la rentabilidad del cultivo en diversas regiones productoras de maíz en México; b) seleccionar maíces bio-fortificados, bio-activos y funcionales con mayor valor agregado, que tengan un impacto en la salud y nutrición de los consumidores, así como un impacto en los sectores pecuario y agroindustrial; c) desarrollar fuentes de germoplasma que contribuyan a reducir riesgos de factores bióticos y abióticos causados por el cambio climático.  Con miras a lograr incidir en las estrategias descritas anteriormente, se ha enfatizado en el desarrollo de germoplasma de maíz enfocado a implementar líneas de investigación enfocadas a: generar maíces con alto contenido de aceite; de grano blanco con calidad nixtamalero-tortillera; de grano amarillo; de alta calidad de proteína (QPM); pigmentados; palomeros (Pop Corn); calidad pozolera; calidad para elote; de calidad forrajera; resistentes a fusarium y a la contaminación con Aflatoxinas; entre otras. En el presente manuscrito se presentan los avances y logros obtenidos en estas líneas de investigación. Con base en la información presentada es posible decir que estamos al frente de grandes retos y oportunidades en la investigación interdisciplinaria de maíz en Latinoamérica. Que nos permitirá desarrollar materiales genéticos que además de buscar hacer frente a riegos inminentes de producción, podamos seleccionar maíces diferenciados, bio-fortificados, que aporten mayor valor agregado y que permitan desarrollar componentes bio-activos, alimentos funcionales y desarrollo de nuevos productos

Componentes genéticos en poblaciones heteróticamente contrastantes de maíz de origen tropical y subtropical.

A diallelic crossbetween 16 tropical and subtropical populations was formedat Iguala, Gro., in the winter nursery 2002 - 2003. Crossesand parents were evaluated during the 2003 growing seasonat INIFAP Bajío Experimental Station, in Celaya, Gto,Mexico. The objective was to identify the best populations tosupport the heterotic structure in our breeding program and assources to derived new inbred lines. Data were analyzedusing the Gardner and Eberhart model, in which variancecomponents can be separated to estimate additive and nonadditivegenetic effects. Results showed that despite theheterotic response involved in the formation of thepopulations, the “tropical x subtropical” heterotic pattern wasexpressed in specific combinations such PABG T x Sint “B”IG and Sint PABG I ACG x Sint “A” IG, with grain yields of12.5 and 12.4 t/ha respectively. These crosses presentedmaximum values of specific heterosis which can be used fordeveloping high-yielding hybrids through reciprocalrecurrent selection. Tropical population Sint “A” IGpresented the highest varietal effect, and because of its goodadaptation in the subtropic is considered an outstandinggermplasm to be incorporated in the Bajío Maize BreedingProgram. The best value of varietal heterosis, which is anindicator of General Combining Ability, was observed inPABG I GH “A” synthetic which can be used as tester. Moredetailed analysis will permit to take advantage of thegermplasm involved to benefit maize breeding programs.Durante el ciclo O-I 02-03 se formó un dialélico con16 poblaciones de origen tropical y subtropical. Las cruzas ysus progenitores fueron evaluados durante el ciclo P-V 2003en el Campo Experimental Bajío- INIFAP. Con el objetivo deidentificar las mejores poblaciones que permitan reforzar losprogramas de hibridación tanto en su estructura heterótica comoen las fuentes de derivación de líneas. La información fueanalizada mediante el método de Gardner y Eberhart con elcual, al separar los componentes de varianza, se estiman losefectos genéticos aditivos y no aditivos. Entre los resultadosmás relevantes se observó que no obstante la respuesta heteróticainvolucrada en la formación de estas poblaciones, elpatrón heterótico “tropical x subtropical” se expresó en combinacionesespecíficas como PABGT x Sint “B”IG y SintPABG I ACG x Sint “A”IG. con rendimientos de 12,5 y 12,4t/ha respectivamente. En estos mismos cruzamientos se obtuvieronlos máximos valores de heterosis específica que podríaaprovecharse a través de Selección Recurrente Recíproca. Lapoblación Sint. “A” IG de origen tropical, presentó el mayorefecto varietal, y por su adaptación al subtrópico constituyeun material prometedor para integrarlo al Programa de MejoramientoGenético del Bajío. El mayor valor de heterosis varietalse observó en el sintético PABG I GH “A” lo cual es unindicador de Aptitud Combinatoria General que puede ser utilizadocomo probador. Un análisis más detallado, permitiráaprovechar este germoplasma en beneficio de los programasde mejoramiento genético de maíz

Simulación del crecimiento de maíces precoces en condiciones de secano.

The use of crop modelingmethodology for the selection of early materials adapted tothose regions was considered in this assay. A growth analysisof 99 early corn landraces was conducted at INIFAP.s BajioExperiment Station (CEBAJ) during the summer of 1997.Using the CERES-MAIZE crop model, the geneticcoefficients were adjusted with such information. Eightgroups were identified in the 99 landraces according to the"emergence to tasseling" and "tasselling to maturity" values(P1 and P5). With these results, it is possible to simulate yieldpotential of the landraces under different rainfedenvironments using soil and historical weather information.As an example, the genetic coefficients of the eight cornlandraces representing each group, were used to simulatetheir yield potential at the northern Guanajuato region, wherecorn is grown mainly under dry land conditions, (300 to 600mm of annual precipitation). Simulation was conducted usingseasonal routine of CERES-MAIZE crop model included onDSSATV 3.1. Eleven years of historical weather informationwere used for this simulation. For this location, Landrace 36presented the highest grain yield under both conditions. AtCEBAJ, Landrace 36 showed the lowest yield out of eight.These results support the use of crop modeling in theselection of genotypes for specific environments.En el presente trabajo se plantea eluso de modelos de simulación para asistir la selección de materialesde ciclo precoz adaptados a dichos ambientes. Duranteel verano de 1997 en el Campo Experimental Bajío (CEBAJ)se realizó un análisis de crecimiento en 99 colectasprecoces de maíz. Con dicha información se calibraron loscoeficientes genéticos requeridos para utilizar el modelo CERES-MAIZE. Apartir de los valores de emergencia a floración(P1) y floración a madurez (P5) se identificaron ocho gruposdentro de las 99 colectas. Con estos resultados, aunados a lautilización de datos históricos de clima y características específicas del suelo, es posible simular el rendimiento potencialde las colectas para cualquier ambiente. A manera de ejemplo:los coeficientes genéticos de colectas representativas de cadauno de los ocho grupos identificados, se usaron para simularsu rendimiento potencial en la región del norte de Guanajuato,donde se registra una precipitación anual de 300 a 600 mm yel maíz se siembra bajo condiciones de temporal (secano). Larutina utilizada fue Seasonal del DSSAT V.3.1. Se emplearondatos climáticos históricos de 11 años. En dicho ambiente elrendimiento de la colecta 36 fue el más alto, tanto en condicionesde temporal, como sin restricción de humedad, mientrasque en el CEBAJ el rendimiento de esta colecta había sido unode los más bajos. El presente trabajo permitió corroborar la utilidadde los modelos de simulación, para identificar la adaptación específica de genotipos a un ambiente determinado

Componentes genéticos en poblaciones heteróticamente contrastantes de maíz de origen tropical y subtropical

A diallelic crossbetween 16 tropical and subtropical populations was formedat Iguala, Gro., in the winter nursery 2002 - 2003. Crossesand parents were evaluated during the 2003 growing seasonat INIFAP Bajío Experimental Station, in Celaya, Gto,Mexico. The objective was to identify the best populations tosupport the heterotic structure in our breeding program and assources to derived new inbred lines. Data were analyzedusing the Gardner and Eberhart model, in which variancecomponents can be separated to estimate additive and nonadditivegenetic effects. Results showed that despite theheterotic response involved in the formation of thepopulations, the “tropical x subtropical” heterotic pattern wasexpressed in specific combinations such PABG T x Sint “B”IG and Sint PABG I ACG x Sint “A” IG, with grain yields of12.5 and 12.4 t/ha respectively. These crosses presentedmaximum values of specific heterosis which can be used fordeveloping high-yielding hybrids through reciprocalrecurrent selection. Tropical population Sint “A” IGpresented the highest varietal effect, and because of its goodadaptation in the subtropic is considered an outstandinggermplasm to be incorporated in the Bajío Maize BreedingProgram. The best value of varietal heterosis, which is anindicator of General Combining Ability, was observed inPABG I GH “A” synthetic which can be used as tester. Moredetailed analysis will permit to take advantage of thegermplasm involved to benefit maize breeding programs.Durante el ciclo O-I 02-03 se formó un dialélico con16 poblaciones de origen tropical y subtropical. Las cruzas ysus progenitores fueron evaluados durante el ciclo P-V 2003en el Campo Experimental Bajío- INIFAP. Con el objetivo deidentificar las mejores poblaciones que permitan reforzar losprogramas de hibridación tanto en su estructura heterótica comoen las fuentes de derivación de líneas. La información fueanalizada mediante el método de Gardner y Eberhart con elcual, al separar los componentes de varianza, se estiman losefectos genéticos aditivos y no aditivos. Entre los resultadosmás relevantes se observó que no obstante la respuesta heteróticainvolucrada en la formación de estas poblaciones, elpatrón heterótico “tropical x subtropical” se expresó en combinacionesespecíficas como PABGT x Sint “B”IG y SintPABG I ACG x Sint “A”IG. con rendimientos de 12,5 y 12,4t/ha respectivamente. En estos mismos cruzamientos se obtuvieronlos máximos valores de heterosis específica que podríaaprovecharse a través de Selección Recurrente Recíproca. Lapoblación Sint. “A” IG de origen tropical, presentó el mayorefecto varietal, y por su adaptación al subtrópico constituyeun material prometedor para integrarlo al Programa de MejoramientoGenético del Bajío. El mayor valor de heterosis varietalse observó en el sintético PABG I GH “A” lo cual es unindicador de Aptitud Combinatoria General que puede ser utilizadocomo probador. Un análisis más detallado, permitiráaprovechar este germoplasma en beneficio de los programasde mejoramiento genético de maíz

Simulación del crecimiento de maíces precoces en condiciones de secano

The use of crop modelingmethodology for the selection of early materials adapted tothose regions was considered in this assay. A growth analysisof 99 early corn landraces was conducted at INIFAP.s BajioExperiment Station (CEBAJ) during the summer of 1997.Using the CERES-MAIZE crop model, the geneticcoefficients were adjusted with such information. Eightgroups were identified in the 99 landraces according to the"emergence to tasseling" and "tasselling to maturity" values(P1 and P5). With these results, it is possible to simulate yieldpotential of the landraces under different rainfedenvironments using soil and historical weather information.As an example, the genetic coefficients of the eight cornlandraces representing each group, were used to simulatetheir yield potential at the northern Guanajuato region, wherecorn is grown mainly under dry land conditions, (300 to 600mm of annual precipitation). Simulation was conducted usingseasonal routine of CERES-MAIZE crop model included onDSSATV 3.1. Eleven years of historical weather informationwere used for this simulation. For this location, Landrace 36presented the highest grain yield under both conditions. AtCEBAJ, Landrace 36 showed the lowest yield out of eight.These results support the use of crop modeling in theselection of genotypes for specific environments.En el presente trabajo se plantea eluso de modelos de simulación para asistir la selección de materialesde ciclo precoz adaptados a dichos ambientes. Duranteel verano de 1997 en el Campo Experimental Bajío (CEBAJ)se realizó un análisis de crecimiento en 99 colectasprecoces de maíz. Con dicha información se calibraron loscoeficientes genéticos requeridos para utilizar el modelo CERES-MAIZE. Apartir de los valores de emergencia a floración(P1) y floración a madurez (P5) se identificaron ocho gruposdentro de las 99 colectas. Con estos resultados, aunados a lautilización de datos históricos de clima y características específicas del suelo, es posible simular el rendimiento potencialde las colectas para cualquier ambiente. A manera de ejemplo:los coeficientes genéticos de colectas representativas de cadauno de los ocho grupos identificados, se usaron para simularsu rendimiento potencial en la región del norte de Guanajuato,donde se registra una precipitación anual de 300 a 600 mm yel maíz se siembra bajo condiciones de temporal (secano). Larutina utilizada fue Seasonal del DSSAT V.3.1. Se emplearondatos climáticos históricos de 11 años. En dicho ambiente elrendimiento de la colecta 36 fue el más alto, tanto en condicionesde temporal, como sin restricción de humedad, mientrasque en el CEBAJ el rendimiento de esta colecta había sido unode los más bajos. El presente trabajo permitió corroborar la utilidadde los modelos de simulación, para identificar la adaptación específica de genotipos a un ambiente determinado