Miguel Ángel Gallegos-Robles

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.

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.