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 (ε280=3,410andε280=3,720 M−1 cm−1) and dihydrocapsaicin (ε280=4,175andε280=4,350 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.
La demanda de forrajes en la Comarca Lagunera ha obligado a que el maíz sea permanente en el padrón de cultivos, para sostener la producción de forraje es necesario manejar adecuadamente el suelo. El objetivo de este estudio fue determinar el impacto de la aplicación de estiércol bovino en el pH, conductividad eléctrica (CE), materia orgánica (MO), nitratos (NO3) y amonio (NH4) de un suelo arcilloso y su efecto en la producción de forraje de maíz. El trabajo se realizó 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 estiércol bovino lechero, testigo absoluto y tratamiento químico 100-150 (kg ha-1; N-P), bajo un diseño bloques al azar, tres repeticiones. La variable medida en planta fue forraje verde. Los tratamientos de 160 y 120 Mg ha-1 de estiércol incrementaron 189 y 180% la MO del suelo, (4 y 3.8%). Para nitratos, los mejores tratamientos fueron 120 y 160Mgha-1deestiércol,convaloresfinalesde22.25y21.33 mg kg-1. La CE se incrementó arriba de 4 dSm-1 en cinco años en los tratamientos de estiércol; no aplicando estiércol en el sexto año bajaron estos valores hasta niveles normales para el desarrollo y producción de maíz con rendimientos arriba de la media regional (45 Mg ha-1) en los tratamientos de estiércol. La aplicación del estiércol con monitoreo regular del suelo es una buena alternativa para el productor lechero, manteniendo buenos rendimientos de forraje y calidad del suelo.
Increasing public concern about negative environmental effects of agricultural practices like conventional chemical fertilization has promoted the evaluation of alternatives like the use of organic nutrient solutions. This study evaluated the effect on fruit yield and commercial and nutraceutical qualities of fresh tomato (Solanum lycopersicum L.) fruits grown under greenhouse conditions fertilized with nutrient solutions prepared from organic materials. Treatments were: a) Inorganic nutritive solution (Steiner); b) Compost tea; c) Vermicompost tea; and d) Vermicompost leachate. Highest fruit yield derived from fertilization with inorganic solution. However, highest antioxidant capacity, soluble solids content and phenolic content were obtained with organic nutrient solutions. Fresh tomatoes obtained with vermicompost leachate had the best nutraceutical quality, higher phenolic content and higher antioxidant capacity, than the inorganically fertilized fruits. Vermicompost leachate is a feasible fertilization alternative for tomato production under greenhouse conditions.
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