<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1405-3195</journal-id>
<journal-title><![CDATA[Agrociencia]]></journal-title>
<abbrev-journal-title><![CDATA[Agrociencia]]></abbrev-journal-title>
<issn>1405-3195</issn>
<publisher>
<publisher-name><![CDATA[Colegio de Postgraduados]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1405-31952007000300295</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Compuestos fenólicos del grano de maíz y su relación con el oscurecimiento de masa y tortilla]]></article-title>
<article-title xml:lang="en"><![CDATA[Phenolic compounds of maize grain and their relationship with darkening in dough and tortilla]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Salinas-Moreno]]></surname>
<given-names><![CDATA[Yolanda]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[López-Reynoso]]></surname>
<given-names><![CDATA[José de J.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[González-Flores]]></surname>
<given-names><![CDATA[Guadalupe B.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Vázquez-Carrillo]]></surname>
<given-names><![CDATA[Gricelda]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Instituto Nacional de Investigaciones Forestales y Agropecuarias Laboratorio de Calidad de Maíz ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Instituto Nacional de Investigaciones Forestales y Agropecuarias Departamento de Fitotecnia ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,Universidad Autónoma Chapingo Departamento de Ingeniería Agroindustrial ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>05</month>
<year>2007</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>05</month>
<year>2007</year>
</pub-date>
<volume>41</volume>
<numero>3</numero>
<fpage>295</fpage>
<lpage>305</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S1405-31952007000300295&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S1405-31952007000300295&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S1405-31952007000300295&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen Algunos de los híbridos y variedades de maíz cultivados en el Estado de México producen masa y tortilla que se oscurecen. No se conoce la causa de este oscurecimiento, pero los compuestos fenólicos del grano podrían estar involucrados. Los objetivos del presente estudio fueron determinar si el contenido de compuestos fenólicos en el grano de maíz está relacionado con el oscurecimiento de masa y tortilla en los maíces evaluados, y obtener el perfil de ácidos fenólicos en muestras de maíz cuya masa y tortilla presenta este fenómeno. Se utilizaron 10 muestras de maíces seleccionadas por el color de sus tortillas: cinco se clasificaron como muestras que oscurecen (MQO) y cinco como muestras que no oscurecen (MQNO). Se cuantificó el contenido de fenoles libres (FL) y totales (FT) en endospermo y pericarpio del grano crudo, así como en masa y tortilla mediante el método de FolinCicalteu; el perfil de ácidos fenólicos se obtuvo por cromatografía líquida de alta resolución (HPLC). La mayor concentración de FL y FT se presentó en el pericarpio del grano, sin diferencias significativas entre las MQO y las MQNO; en el endospermo se encontró una mayor concentración de estos compuestos en las MQO con relación a las MQNO. Esta misma tendencia se observó para masa y tortilla, donde el contenido de FT en esta última fue 39 % mayor en las MQO que en las MQNO. En el pericarpio y endospermo del grano crudo de los dos grupos de muestras se observaron los ácidos p-cumárico, ferúlico y sinápico, con mayor proporción del ferúlico. Estos mismos ácidos se encontraron en el extracto de fenoles libres de masa de ambos grupos de muestras.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract Some maize varieties and hybrids cultivated in the State of México become dark when made into dough and tortillas. The cause of this darkening is not known, but phenolic compounds in the grain could be involved. The objectives of this study were to determine whether the content of phenolic compounds in maize grain is related to darkening of dough and tortillas made from the evaluated maize varieties, and to obtain the profile of phenolic acids in samples of maize whose dough and tortillas exhibit this phenomenon. Ten samples of maize selected for the color of their tortillas were used: five were classified as samples that darken (MQO) and five were classified as samples that do not darken (MQNO). The content of free (FL) and total (FT) phenols was quantified in the endosperm and pericarp of the raw grain, as well as in dough and in tortillas following the method of Folin-Cicalteu; the phenolic acid profiles was obtained with high precision liquid chromatography (HPLC). The highest concentration of FL and FT was found in the grain pericarp, with no significant differences between the MQO and MQNO. In the endosperm a higher concentration of these compounds was found in the MQO than in the MQNO. This same trend was observed for dough and tortilla, where FT content of the latter was 39% higher in MQO than in MQNO. In the raw-grain pericarp and endosperm of both groups of samples p-cumaric, ferulic, and sinapic acids were observed; the proportion of ferulic acid was higher. These same acids were found in the free phenol extract from dough of both groups of samples.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Ácidos fenólicos]]></kwd>
<kwd lng="es"><![CDATA[maíz]]></kwd>
<kwd lng="es"><![CDATA[nixtamalización]]></kwd>
<kwd lng="es"><![CDATA[oscurecimiento]]></kwd>
<kwd lng="es"><![CDATA[tortilla]]></kwd>
<kwd lng="en"><![CDATA[Phenolic acids]]></kwd>
<kwd lng="en"><![CDATA[maize]]></kwd>
<kwd lng="en"><![CDATA[nixtamalization]]></kwd>
<kwd lng="en"><![CDATA[darkening]]></kwd>
<kwd lng="en"><![CDATA[tortilla]]></kwd>
</kwd-group>
</article-meta>
</front><back>
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