The isoflavone aglycones daidzein and genistein are phytoestrogens that ameliorate the symptoms of menopause and assist in the prevention of chronic diseases. These compounds have been studied mainly in soya but have also been detected in faba beans (Vicia faba L.). Since little information is available concerning the content of isoflavone aglycones in faba beans from Mexico, the present study aimed to establish the presence and concentrations of daidzein and genistein in stems of faba bean cultivars from the Mexican central plateau. Cultivars C-281, C-146, C-160, C-89, C-288, C-181, C-93 and C-Zac22 were grown under greenhouse conditions and 6 to 7 week-old stems were harvested. The presence of daidzein and genistein in these tissues was confirmed by thin layer chromatography using a solvent system containing toluene-ethyl acetateacetone- formic acid (74:14.8:7.4:3.8). High-pressure liquid chromatographic analysis revealed significant differences (p≤0.01) in the concentrations of aglycones with levels of genistein in the range 0.30 to 0.85 mg kg-1 dry weight (DW) and of daidzein, which was more abundant in all cultivars, present in the concentration range 34.92 to 59.98 mg kg-1 DW. Stems of cultivars C-89, C-181, C-281 and C-146 were exceptional for their concentrations of isoflavones and may represent good alternative sources of phytoestrogens.

Las isoflavonas agliconas, daidzeína y genisteína, son fitoestrógenos que benefician la salud, mejoran los síntomas de la menopausia y previenen enfermedades crónicas. Estos compuestos se han estudiado principalmente en soya (Glicine max), pero también se han detectado en habas (Vicia faba L.). Dado que hay poca información disponible sobre el contenido de isoflavonas agliconas en habas de México, el presente estudio tuvo como objetivo establecer la presencia y las concentraciones de daidzeína y genisteína en tallos de cultivares provenientes de la Meseta Central de México. Los cultivares C-281, C-146, C-160, C-89, C-288, C-181, C-93 y C-Zac22 se sembraron en un invernadero para la obtención de tallos entre 6-7 semanas posteriores a la siembra. Se comprobó la presencia de daidzeína y genisteína por cromatografía en capa fina usando un sistema de solventes de tolueno-acetato de etilo-acetona-ácido fórmico (74:14,8:7,4:3,8). Los resultados de la cromatografía líquida de alta resolución mostraron diferencias significativas (p≤0,01) con concentraciones para genisteína entre 0,30-0,85 mg kg-1 y daidzeína entre 34,92-59,98 mg kg-1 de materia seca, siendo este último el metabolito más abundante en todos los cultivares. Los cultivares C-89, C-181, C-281 y C-146 fueron sobresalientes en la concentración de isoflavonas, por esta razón, pueden ser una buena fuente de fitoestrógenos.

Curing vanilla is a fundamental activity in the vanilla product system, because it generates dehydrated vanilla, a value-added product demanded by the national and international markets. In this regard, it is important to know the level of competition in this segment of the production chain. The purpose of this research was to estimate the competitiveness of two vanilla curing systems in the Totonacapán region. The methodology uses the policy analysis matrix (PAM), which generates the private cost ratio (PCR) and the domestic resources cost ratio (DRCR), which indicate the level of economic efficiency of the systems. The information was obtained in the study region during 2009, from face to face interviews with 15 vanilla curers in their curing plants, based on a directed sampling. The traditional curing system (sun wilting) shows an efficient use of domestic resources and has a comparative advantage over other systems; it is profitable, while the heating furnace system resulted in low efficiency and showed no comparative advantage.

El beneficiado de vainilla es una actividad fundamental en el Sistema Producto Vainilla, debido a que genera vainilla deshidrata, producto con valor agregado demandado por el mercado nacional e internacional. En este sentido, es importante conocer el nivel de competitividad de este segmento de la cadena productiva. El propósito de esta investigación es estimar la competitividad de dos sistemas de beneficiado de vainilla en la región del Totonacapán. La metodología utiliza la matriz de análisis de política (MAP), que genera la relación de costo privado (RCP) y la de costo de los recursos internos (RCI), que señalan el nivel de eficiencia económica de los sistemas. La información se obtuvo en la región de estudio durante 2009, con entrevistas cara a cara a 15 beneficiadores de vainilla en sus beneficios, a partir de un muestreo dirigido. El sistema de beneficiado tradicional (bajo sol) muestra eficiencia en el uso de los recursos internos y ventaja comparativa, resultando rentable, en tanto que el sistema de horno calorífico resulto con bajos niveles de eficiencia y no muestra ventaja comparativa.

O estresse salino afeta o crescimento e a produtividade das culturas. Neste ensaio determinou-se o crescimento, o rendimento do fotossistema II (PSII) e a concentração de K+ e Na+ nas raízes, caules, folhas velhas e jovens das variedades mexicanas de arroz: Tres Ríos e Cotaxtla. Ademais, estudou-se a relação K+/Na+ na parte aérea e raízes de ambas variedades. O experimento foi conduzido em uma câmara de crescimento, sob condições controladas, em delineamento inteiramente ao acaso, com arranjo fatorial 2 x 2 (Variedade x Salinidade) e 12 repetições. As plantas foram crescidas em solução hidropônica durante 15 dias e posteriormente, uma parte foi tratada com 100 mM de NaCl; e o restante como plantas controle (sem tratamento com NaCl), as quais foram crescidas paralelamente. O estresse salino provocou reduções de 20 e 15% na longitude dos brotos e raízes, respectivamente na variedade Tres Ríos; entretanto, na variedade Cotaxtla não apresentaram diferenças significativas nestas variaveis com relação ao tratamento controle. O peso da matéria seca reduziu-se 24% na variedade Tres Ríos. O rendimento quântico do PSII diminuiu 30% ao terceiro dia da aplicação dos tratamentos em ambas variedades. A concentração de Na+ foi significativamente maior (p ≤ 0,05) nas plantas tratadas com NaCl. No entanto, na variedade Tres Ríos, o rendimento do PSII diminuiu completamente depois de seis dias da aplicação dos tratamentos, a concentração de K+ nos talos e folhas velhas também foi diminuída e registrou-se a menor relação K+/Na+ nos brotos, o que poderia indicar que se trata de uma variedade mais suscetível à salinidade com relação a variedade Cotaxtla.

Salt stress affects crop growth and productivity. In this study, we determined the growth, yield of photosystem II (PSII), and K+ and Na+ concentration in root, stem, old leaves, and young leaves of two Mexican varieties of rice, Tres Ríos and Cotaxtla. In addition, the K+/Na+ ratio in stem and root of both varieties was determined. The experiment was conducted in a growth chamber under controlled conditions, under a completely randomized distribution, with a 2 x 2 (Variety x Salinity) factorial arrangement and 12 replications. Plants were grown in a hydroponic solution for 15 days and then some of them were treated with 100 mM NaCl; control plants (without NaCI treatment) were grown in parallel. Salt stress caused 20 and 15% reductions in stem and root length, respectively, in the variety Tres Ríos, while in the variety Cotaxtla no significant differences were observed in these variables compared to the control. Dry matter weight decreased by 24% in the variety Tres Ríos. The quantum yield of PSII decreased by 30% the third day of treatment application, in both varieties. Na+ concentration was significantly (p ≤ 0.05) higher in NaCI-treated plants. In the variety Tres Ríos, the yield of PSII was completely eradicated six days after treatment implementation, while the K+ concentration in stem and older leaves also decreased and the lowest K+/ Na+ ratio in stem was recorded, which could indicate that it is more susceptible to salinity than the variety Cotaxtla.