Cirilo Vázquez-Vázquez

Measurement of Capsaicinoids in Chiltepin Hot Pepper: A Comparison Study between Spectrophotometric Method and High Performance Liquid Chromatography Analysis

Direct spectrophotometric determination of capsaicinoids content in Chiltepin pepper was investigated as a possible alternative to HPLC analysis. Capsaicinoids were extracted from Chiltepin in red ripe and green fruit with acetonitrile and evaluated quantitatively using the HPLC method with capsaicin and dihydrocapsaicin standards. Three samples of different treatment were analyzed for their capsaicinoids content successfully by these methods. HPLC-DAD revealed that capsaicin, dihydrocapsaicin, and nordihydrocapsaicin comprised up to 98% of total capsaicinoids detected. The absorbance of the diluted samples was read on a spectrophotometer at 215–300 nm and monitored at 280 nm. We report herein the comparison between traditional UV assays and HPLC-DAD methods for the determination of the molar absorptivity coefficient of capsaicin ( and  M−1 cm−1) and dihydrocapsaicin ( and  M−1 cm−1), respectively. Statistical comparisons were performed using the regression analyses (ordinary linear regression and Deming regression) and Bland-Altman analysis. Comparative data for pungency was determined spectrophotometrically and by HPLC on samples ranging from 29.55 to 129 mg/g with a correlation of 0.91. These results indicate that the two methods significantly agree. The described spectrophotometric method can be routinely used for total capsaicinoids analysis and quality control in agricultural and pharmaceutical analysis.

Impacto del estiércol bovino en el suelo y producción de forraje de maíz

La demanda de forrajes en la Comarca Lagunera ha obligado a que el maiz sea permanente en el padron de cultivos, para sostener la produccion de forraje es necesario manejar adecuadamente el suelo. El objetivo de este estudio fue determinar el impacto de la aplicacion de estiercol bovino en el pH, conductividad electrica (CE), materia organica (MO), nitratos (NO3) y amonio (NH4) de un suelo arcilloso y su efecto en la produccion de forraje de maiz. El trabajo se realizo en la Facultad de Agricultura y Zootecnia-UJED, en 1998 a 2007. Los tratamientos de estudio fueron 40, 80, 120 y 160 Mg ha-1 de estiercol bovino lechero, testigo absoluto y tratamiento quimico 100-150 (kg ha-1; N-P), bajo un diseno bloques al azar, tres repeticiones. La variable medida en planta fue forraje verde. Los tratamientos de 160 y 120 Mg ha-1 de estiercol incrementaron 189 y 180% la MO del suelo, (4 y 3.8%). Para nitratos, los mejores tratamientos fueron 120 y 160 Mg ha-1 de estiercol, con valores finales de 22.25 y 21.33 mg kg-1. La CE se incremento arriba de 4 dSm-1 en cinco anos en los tratamientos de estiercol; no aplicando estiercol en el sexto ano bajaron estos valores hasta niveles normales para el desarrollo y produccion de maiz con rendimientos arriba de la media regional (45 Mg ha-1) en los tratamientos de estiercol. La aplicacion del estiercol con monitoreo regular del suelo es una buena alternativa para el productor lechero, manteniendo buenos rendimientos de forraje y calidad del suelo

Productividad de genotipos de maíz forrajero bajo fertilización orgánica y propiedades físico-químicas del suelo

The Lagunera region is the main region of dairy cattle exploitation in the whole country, a process that demands large quantities of forage of the highest quality. Therefore, the objective of this work was to evaluate the forage production on dry basis of three forage corn hybrids, using different amounts of vermicompost and bovine manure for fertilization, as well as to evaluate the effect of these treatments on the physico-chemical properties ground. Under organic fertilization, HT 6806Y, ABT hybrids were tested; DAS2306, from Dow Agrosciences and RX717, from Asgrow. The experiment was established in the Faculty of Agriculture and Zootechnics of the Juarez University of the state of Durango. A randomized blocks design was used in split plots, with three repetitions. The experiment was carried out in the spring-summer cycle of 2014. In the comparison analysis of means the hybrid HT6806Y proved to be superior (p≤ 0.05) with a production of 69.91 t ha-1 of green forage, under the treatment T3 (160 t ha-1 of solarized manure with 3 t ha-1 of vermicompost); on the other hand, the three hybrids showed a good response to organic fertilization, since they all obtained acceptable productions of dry matter of 25.89 t ha-1 (HT6806Y), 26.04 t ha-1 (RX717) and 25.33 t ha-1 (DAS2306 ). The mixtures of nitrogen sources tested in this study turned out to be a good alternative that competes with the synthetic sources of nitrogen, improving some variables of yield and quality of the forages.