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.

A study was conducted in 2006 to determine the prevalence of Salmonella on three cantaloupe farms in Matamoros, Coahuila, Mexico, and on one farm that cultivates chile peppers var. Bell in Culiacán, Sinaloa, Mexico. Samples from cantaloupe farms consisted of cantaloupe rinses, irrigation water, water from furrows in the field, and workers' hands. Samples from the chile pepper farm consisted of rinses of chile peppers obtained at the field, pepper rinses obtained at the packing house, and irrigation water from the field. A total of 55 samples were obtained from both production systems. Twelve and 10 samples from the cantaloupe and chile pepper production systems, respectively, tested positive for Salmonella according to a traditional culture method. The difference between the proportion of Salmonella-positive samples from the cantaloupe production system (12 of 28 = 0.43) and the chile pepper production system (10 of 27 = 0.37) was not statistically significant (P > 0.05). A PCR-restriction fragment length polymorphism (RFLP) method based on the fliC gene was used to determine the serotype of the isolates. Salmonella Typhimurium was the only serotype found associated with the cantaloupe production system, whereas both Salmonella Typhimurium and Enteritidis serotypes were found associated with the chile pepper production system. Results showed that 91% (20 of 22) and 9% (2 of 22) of the isolates from both agricultural systems matched with the Salmonella Typhimurium and Salmonella Enteritidis reference strain restriction profiles, respectively. This study demonstrates the utility of the PCR-RFLP technique for determining the serotypes of Salmonella isolates obtained from cantaloupe and chile pepper production systems.

The objective of this research was to evaluate the production and phytochemical quality of cucumber (Cucumis sativus) fruits, in response to the foliar application of different seaweed extracts. This study was carried out under shadow mesh conditions in the autumn–winter agricultural cycle at the Instituto Tecnológico de Torreón, Torreón, Coahuila, Mexico. The experimental design was completely random, using six treatments with six repetitions each. The treatments evaluated were: Macrocystis pyrifera, Bryothamnion triquetrum, Ascophyllum nodosum, Grammatophora spp., Macrocystis integrifolia, and a control treatment with inorganic fertilization. The substrate used was a mixture of sand and vermicompost. The yield, commercial size, and phytochemical compounds of the fruit were evaluated. Results showed that the yield using Steiner solution (6.75 kg m−2) was higher than that obtained with Bryothamnion triquetrum algae (6.07 kg m−2). Regarding the phenolic content, the extracts surpassed the control treatment, with Macrocystis pyrifera and Macrocystis integrifolia being statistically equal, with values of 47.37 and 43.73 mg equiv. of Ac. Gallic 100 g fresh weight, respectively. The antioxidant capacity by ABTS+ and DPPH+ methods was higher using the treatment with Macrocystis pyrifera algae with 149.4 and 454.1 μM equiv Trolox/100 g fresh base, respectively. This treatment also presented the highest value of vitamin C with 5.07 mg/100 g fresh base, being 27% greater than the control treatment. Algae extracts increased the quality of the fruits by obtaining the highest antioxidant capacity, making their use a viable option to minimize the application of conventional fertilizers, thereby attenuating the effects on the environment and improving the health of the population.

Species belonging to the genus Salmonella are an important cause of enteric fevers, gastroenteritis, and septicemia, and the pathogens are commonly transmitted through contaminated food. In this study, polymerase chain reaction (PCR) amplification of a 287-bp region of the invA gene was compared to a microbiological technique to determine the presence of Salmonella in retail beef and in cantaloupe rinse samples. Both methods showed the same level of sensitivity, detecting 1 CFU/25 g of meat after enrichment for 24 h at 42• C. The presence of Salmonella was determined in 50 commercial top sirloin beef samples that were not artificially inoculated. Three samples were positive by the microbiological method, and these samples and an additional sample were positive by the PCR. Both methods were also used to test surface rinses of cantaloupes collected from 4 farms in Nayarit, Mexico. Salmonella was detected by the microbiological method in 9 of 20 samples (45%), whereas the pathogen was detected by the PCR in 11 samples (55%). This study demonstrates the utility of the PCR targeting the invA gene to determine the presence of Salmonella spp. in beef and cantaloupe samples.

Potassium (K) influences the variables that determine quality of fruit and the concentration of phytonutrients to human health and therefore consumer preferences. The objective of this study was to evaluate the effect of different concentrations of K in the nutrient solution (5, 7, 9 and 11 mM of K) on yield and quality of Cantaloupe fruits under greenhouse conditions. The experiment was conducted in pots using a completely randomized design with 15 replications. Analysis of variance, correlation, regression and multiple comparisons among means (Tukey p<0.05) were performed. Results showed higher values of yield, average fruit weight, equatorial diameter, pulp thickness, fruit firmness, soluble solids content, phenolic content and antioxidant capacity of fruits at the concentrations of 9 and 11 mM of K. All variables, except equatorial diameter, increased their values as K concentrations increased, showing a lineal, positive and significant trend, which evidences that the optimal dose of K in muskmelon is higher than 11 mM, being suggested for future research, to evaluate concentrations above this value.

El uso de microorganismos promotores del crecimiento, tiene grandes beneficios, los que ayudan a disminuir el uso excesivo de fertilizantes y pesticidas usados en la producción agrícola. Los objetivos fueron aislar, caracterizar y evaluar en campo cepas del género Bacillus spp., en el rendimiento de maíz forrajero. El estudio fue realizado en el campo experimental de la Facultad de Agricultura y Zootecnia en la Universidad Juárez del Estado de Durango en la región de la Comarca Lagunera, ubicada en el norte de México, durante 2018. Se aislaron y se identificaron cepas de Bacillus spp., a partir de raíces de plantas de zacate Johnson (Sorghum halepense), maíz (Zea mays) y sorgo (Sorghum bicolor), preseleccionadas de acuerdo a la capacidad para fijar nitrógeno y caracterizadas por secuenciación del gen 16S rDNA. Fueron identificadas dos cepas de Bacillus amyloliquefaciens y tres más de Bacillus subtilis. Posteriormente, evaluadas en campo durante los ciclos primavera-verano (P-V) y otoño-invierno (O-I) del año 2018, en dos híbridos de maíz (Galáctico y AG 614). La inoculación con la cepa Bacillus amyloliquefaciens favoreció un buen resultado para peso fresco de la planta, peso seco, diámetro de tallo, número de elotes, peso fresco de raíz y en longitud de la raíz; mientras que Bacillus subtilis, mejor en peso fresco de raíz respecto al testigo. Con referencia al área foliar y porcentaje de proteína cruda, no se observó diferencia significativa entre los tratamientos con resultados similares al tratamiento químico. Finalmente, para diámetro de raíz, el resultado más favorable se presentó con el tratamiento químico. Los mejores resultados fueron encontrados durante el ciclo P-V.

El cultivo de nuez pecanera en México es una actividad en amplio crecimiento, sobre todo en estados del norte, debido a la amplia adaptación climática y edafológica, así como por las condiciones de mercado y atractiva rentabilidad que presenta, al canalizarse a Estados Unidos de América. El estado de Coahuila, colindante con aquél país cuenta con 13 mil hectáreas con el cultivo distribuidas en toda la entidad y es centro de origen del mismo, por lo cual el propósito de este estudio fue caracterizar el proceso productivo, comercialización y agregación de valor a la nuez en la parte norte de la entidad (región de los cinco manantiales) a fin de identificar en el sistema producto áreas de oportunidad que puedan aprovechar los actores involucrados en el proceso para obtener mejores beneficios. Para ello durante el período 2006 a 2007 se aplicaron dos encuestas con preguntas abiertas y cerradas; una se aplicó a productores y la otra a comercializadores-transformadores y los resultados lograron clarificar los canales de comercialización, así como los márgenes comerciales del producto, concluyendo que se requiere fortalecer técnicamente la asistencia productiva; mejorar la presentación del producto previo a su comercialización, y apoyar la transformación de la nuez para mejorar el desempeño de éste sistema de producción.

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