Compuestos fenólicos y capacidad antioxidante de genotipos de maíz pigmentado (azul/morado)

El maíz (Zea mays L.) es uno de los principales alimentos que constituyen la dieta de los mexicanos. Además, México es un país que cuenta con diversas razas de maíz con diferentes pigmentaciones. Los maíces con granos pigmentados se distinguen por presentar alto contenido de compuestos fenólicos y capacidad antioxidante, que pueden ser utilizados para el desarrollo de productos funcionales en beneficio de la salud. El objetivo de este trabajo fue evaluar y comparar el contenido de compuestos fenólicos (fenoles y flavonoides totales, antocianinas y taninos condensados), además de los niveles de capacidad antioxidante (DPPH y ABTS) en cinco genotipos de maíz azul/morado de diferentes razas (Kculli, Tuxpeño, Chalqueño y Cónicos), identificados como Morado Peruano (MPE), Morado Antonio Narro (MAN), Morado Veracruz (MV), Morado Sinaloa (MS) y Morado Poblano (MP). Los resultados obtenidos indican que los genotipos MPE y MAN presentaron los niveles más altos en fenoles totales y antocianinas, lo que resultó en mayores propiedades antioxidantes. El presente estudio permite identificar genotipos de maíz con alta concentración de compuestos antioxidantes que pueden ser utilizados para el desarrollo de suplementos alimenticios

Grain yield, nutritional, polyphenols and antioxidant capacity in accessions of sorghum (Sorghum bicolor L. Moench)

Sorghum is an economically important crop in developing countries. The objective of this study was to compare the agronomic performance, and the chromatic, nutritional and nutraceutical properties of nineteen sorghum accessions cultivated in Tamaulipas, Mexico. Results showed that the grain yield (15.22 to 70.18 g per plant), days to flowering (73 to 92 days), panicle length (16.63 to 27.67 cm), luminosity (27.14 to 57.75), chromaticity (5.65 to 15.33) and hue angle (38.49 to 82.66) varied. The percentage of protein (7.33 to 3.43%), fiber (0.60 to 3.03%) and carbohydrates (70.17 to 78.39%) also varied. Grains had a high concentration of magnesium, phosphorus and potassium; the content of total phenols and total flavonoids (free + bound) was found in a range of 117.61 to 2367.01 mg GAE/100 g and 22.52 to 613.92 mg CE/100 g, respectively. The antioxidant capacities (free + bound) showed ranges from 65.09 to 2,017.58 μmol TE/100 g, 43.13 to 1,907.99 μmol TE/100 g and 107.20 to 3,523.20 μmol TE/100 g using the ABTS, DPPH and FRAP methods, respectively. A negative correlation (-0.36) was observed between grain yield and days to flowering. In addition, a positive correlation between phenolic compounds and antioxidant capacity. These results confirm an important genetic diversity among the studied accessions of sorghum

Seroprevalence of SARS-CoV-2 Antibodies and Factors Associated with Seropositivity at the University of Salamanca: The DIANCUSAL Study

© 2021 by the authors[Background]: Systematic screening for antibodies against SARS-CoV-2 is a crucial tool for surveillance of the COVID-19 pandemic. The University of Salamanca (USAL) in Spain designed a project called “DIANCUSAL” (Diagnosis of New Coronavirus, COVID-19, in University of Salamanca) to measure antibodies against SARS-CoV-2 among its ~34,000 students and academic staff, as the influence of the university community in the spread of the SARS-CoV-2 pandemic in the city of Salamanca and neighboring towns hosting USAL campuses could be substantial.[Objective]: The aim of this study was to estimate the prevalence of SARS-CoV-2 antibodies among USAL students, professors and staff and to evaluate the demographic, academic, clinical and lifestyle and behavioral factors related to seropositivity.[Methodology]: The DIANCUSAL study is an ongoing university population-based cross-sectional study, with the work described herein conducted from July–October 2020. All USAL students, professors and staff were invited to complete an anonymized questionnaire. Seroprevalence of anti-SARS-CoV-2 antibodies was detected and quantified by using chemiluminescent assays for IgG and IgM. Principal findings: A total of 8197 (24.71%) participants were included. The mean age was 31.4 (14.5 SD) years, and 66.0% of the participants were female. The seroprevalence was 8.25% overall and was highest for students from the education campus (12.5%) and professors from the biomedical campus (12.6%), with significant differences among faculties (p = 0.006). Based on the questionnaire, loss of smell and fever were the symptoms most strongly associated with seropositivity, and 22.6% of seropositive participants were asymptomatic. Social distancing was the most effective hygiene measure (p = 0.0007). There were significant differences in seroprevalence between participants with and without household exposure to SARS-CoV-2 (p = 0.0000), but not between students who lived in private homes and those who lived in dormitories. IgG antibodies decreased over time in the participants with confirmed self-reported COVID-19 diagnoses.[Conclusions]: The analysis revealed an overall 8.25% seroprevalence at the end of October 2020, with a higher seroprevalence in students than in staff. Thus, there is no need for tailored measures for the USAL community as the official average seroprevalence in the area was similar (7.8% at 22 June and 12.4 at 15 November of 2020). Instead, USAL members should comply with public health measures.The DIANCUSAL (Diagnosis of New Coronavirus, COVID-19, in University of Salamanca) study was funded by a grant from the University of Salamanca (USAL)

Nutritional and nutraceutical changes in blue corn (Zea mays) stored at different temperatures

AbstractRecently, blue/purple maize has gained prominence for its beneficial health properties, however, in Mexico, post-harvest handling of pigmented corn grains reaches losses of up to 80%, where in addition to quantity, nutritional and nutraceutical quality is seriously affected by inadequate storage conditions. The objective of this research was to quantify the nutritional and nutraceutical changes in blue corn grains stored for four months at 6, 25, and 35 °C. The results indicate that, at the fourth month of storage, temperatures affected the nutritional content to a different extent, with decreases of 66.83% in moisture and 57.79% in protein, and with increases of 10.92% in carbohydrates and 49.67% in starch. The concentration of phenols, flavonoids and total anthocyanins decreased by 49.33, 61.09 and 53.33%, after four months of storage at 35 °C, which were reflected in reductions in antioxidant capacity by 17.87, 17.84 and 18.93% for 2, 2− diphenyl − 1−picrylhydrazyl (DPPH), 2,2-azino-bis (3−ethylbenzothiazoline −6−sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP), respectively. However, no significant changes in the nutraceutical content were generated during the storage of the grains at 6 °C. High temperatures over a prolonged storage period could seriously affect the concentrations of functional compounds in blue/purple corn kernels before consumption

Plastic colored paddings and its effect on the foliar micromorphology of husk tomato (Physalis ixocarpa Brot.)

Objective: To assess the effect of colored plastic paddings on the foliar micromorphology of husk tomato (Physalis ixocarpa Brot.). Design / methodology / approach: A completely randomized statistical model was used with five treatments (black, white, blue, red and green paddings) with three repetitions each, 95% reliability and Tukey's mean test (P ? 0.05). To quantify the normalized difference vegetation index (NDVI) a portable GreenSeeker® sensor was used. To measurement of total soluble solids a Atago® Digital refractometer, the density and stomatal index, length and width of stomata were determined with a Carl Zeiss microscope with an integrated camera and the AxionVisionRel measurement software 4.8. Results: The results show no significant differences in the NDVI and total soluble solids. The micromorphological variables of adaxial stomatal density and adaxial stomatal index were superior in the blue paddings and exceeded black paddings in 95 % and 50 % respectively. The rest of the micromorphological variables were statistically similar, the yield per plant was statistically similar in the black, white, red and green, while blue paddings yield less. Study limitations / implications: blue paddings improve micromorphological characteristics, but not the yield of husk tomato crops. Findings / conclusions: Some of the foliar micromorphological characteristics of the husk tomato crop are modified by colored plastic paddings; however, the improvement in these variables does not necessarily improve the crop yield, probably due to the absorbed and reflected radiation by the colored plastic paddings

Plastic colored paddings and its effect on the foliar micromorphology of husk tomato (Physalis ixocarpa Brot.)

Objective: To determine the effect of colored plastic mulches on the foliar micromorphology of husk tomato (Physalis ixocarpa Brot). Design / methodology / approach: A completely randomized statistical model was used with five treatments (black, white, blue, red and green padding) with three repetitions each, 95% reliability and Tukey's mean test ?0.05. To quantify the normalized difference vegetation index (NDVI) a portable GreenSeeker® sensor was used, for the measurement of total soluble solids an Atago® brand Digital refractometer, the density and stomatal index, length and width of stomata were determined with a microscope Carl Zeeis with integrated camera and AxionVisionRel measurement software 4.8. Results: The results did not show significant differences in NDVI and total soluble solids. The micromorphological variables of adaxial stomatal density and adaxial stomatal index, were superior in the blue padding and exceeded the black padding in 95 % and 50 % respectively, the rest of the micromorphological variables were statistically similar, the yield per plant was statistically similar in the black, white, red and green padding, while blue was less yield. Study limitations / implications: The blue padding improves micromorphological characteristics, but not the yield of the husk tomato crop. Findings / conclusions: With colored plastic padding, some of the foliar micromorphological characteristics of the husk tomato crop are modified, however, an improvement in these variables does not necessarily improve the crop yield, which is probably due to the radiation absorbed and reflected by colored plastic padding. Keywords: Physalis ixocarpa, stomatic density, stomatic index, epidermal cells.  Objective: To assess the effect of colored plastic paddings on the foliar micromorphology of husk tomato (Physalis ixocarpa Brot.). Design / methodology / approach: A completely randomized statistical model was used with five treatments (black, white, blue, red and green paddings) with three repetitions each, 95% reliability and Tukey's mean test (P ? 0.05). To quantify the normalized difference vegetation index (NDVI) a portable GreenSeeker® sensor was used. To measurement of total soluble solids a Atago® Digital refractometer, the density and stomatal index, length and width of stomata were determined with a Carl Zeiss microscope with an integrated camera and the AxionVisionRel measurement software 4.8. Results: The results show no significant differences in the NDVI and total soluble solids. The micromorphological variables of adaxial stomatal density and adaxial stomatal index were superior in the blue paddings and exceeded black paddings in 95 % and 50 % respectively. The rest of the micromorphological variables were statistically similar, the yield per plant was statistically similar in the black, white, red and green, while blue paddings yield less. Study limitations / implications: blue paddings improve micromorphological characteristics, but not the yield of husk tomato crops. Findings / conclusions: Some of the foliar micromorphological characteristics of the husk tomato crop are modified by colored plastic paddings; however, the improvement in these variables does not necessarily improve the crop yield, probably due to the absorbed and reflected radiation by the colored plastic paddings

Mathematical models to estimate forage production in southeastern Coahuila Mexico

Objective: Calibrate two non-linear models, in three intermediate triple hybrids, by theoretically comparing the accumulation of dry matter in relation to the days after sowing. Methodology: The cuts were every 14 days, from 30 to 170 das, and were adjusted to the Logistic and Richards models. The experimental design was a randomized block, with three replications. Results: The models explained most of the total dry matter yield in corn, observed in the field at 83%. The best fit model was the logistic model in cultivar AN447 and the Richards model in cultivar A7573, both with R2=0.98. The maximum yield simulated with the Richards model was shown in AN447 with 22,616 kg DM ha-1 and the lowest in AN388 with 10,970 kg DM ha-1. Limitations/Implications: Tests of other models in the same conditions and in other environmental conditions with the models under study. Conclusion: The Logistic model allows to simulate with greater precision the yield of dry matter in corn, by using the days after planting as an independent variable

Foliar Application of Zinc Oxide Nanoparticles and Zinc Sulfate Boosts the Content of Bioactive Compounds in Habanero Peppers

The physiological responses of habanero pepper plants (Capsicum chinense Jacq.) to foliar applications of zinc sulphate and zinc nano-fertilizer were evaluated in greenhouse trials. The effect of the supplement on fruit quality of habanero pepper was particularly observed. Habanero pepper plants were grown to maturity, and during the main stages of phenological development, they were treated with foliar applications of Zn at concentrations of 1000 and 2000 mg L−1 in the form of zinc sulfate (ZnSO4) and zinc oxide nanoparticles (ZnO NPs). Additional Zn was not supplied to the control treatment plants. ZnO NPs at a concentration of 1000 mg L−1 positively affected plant height, stem diameter, and chlorophyll content, and increased fruit yield and biomass accumulation compared to control and ZnSO4 treatments. ZnO NPs at 2000 mg L−1 negatively affected plant growth but significantly increased fruit quality, capsaicin content by 19.3%, dihydrocapsaicin by 10.9%, and Scoville Heat Units by 16.4%. In addition, at 2000 ZnO NPs mg L−1 also increased content of total phenols and total flavonoids (soluble + bound) in fruits (14.50% and 26.9%, respectively), which resulted in higher antioxidant capacity in ABTS (2,2′azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), DPPH (2,2-diphenyl-1-picrylhydrazyl), and FRAP (ferric reducing antioxidant power) (15.4%, 31.8%, and 20.5%, respectively). These results indicate that application of ZnO NPs could be employed in habanero pepper production to improve yield, quality, and nutraceutical properties of fruits

Zinc Oxide Nanoparticles Boosts Phenolic Compounds and Antioxidant Activity of Capsicum annuum L. during Germination

The effects of zinc oxide nanoparticles on seed germination and seedling growth of Capsicum annuum L. were determined in this research. Total phenols content, total flavonoids, and condensed tannins, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant capacity was determined. Results indicated that treatment with zinc oxide nanoparticles (ZnO-NPs) improved seed germination rate during the first seven days. The seed vigor germination increased 123.50%, 129.40% and 94.17% by treatment with ZnO-NPs suspensions at 100, 200 and 500 ppm, respectively. The morphological parameters tested revealed that ZnO-NPs treatments did not significantly affect plumule development, but they had a significant impact (p ≤ 0.01) on radicle length. Suspensions at 100, 200 and 500 ppm of ZnO-NPs inhibited seedling radicle growth and promoted accumulation of phenolic compounds, with a phytotoxic effect in this organ. Results suggested that zinc oxide nanoparticles influence seed vigor and seedling development and promoted the accumulation of desirable phenolic compounds in the radicle

Insecticidal Effect of Zinc Oxide and Titanium Dioxide Nanoparticles against Bactericera cockerelli Sulc. (Hemiptera: Triozidae) on Tomato Solanum lycopersicum

The use of nanoparticles (NPs) has generated an alternative pest control. The objective was to evaluate the insecticidal effect of zinc oxide nanoparticles (ZnO NPs), titanium dioxide nanoparticles (TiO2 NPs), and their combination on Bactericera cockerelli (Hemiptera: Triozidae) second-stage nymphs under laboratory and greenhouse conditions in tomato. The laboratory research was carried out with the leaf immersion bioassay method under a complete randomized design, and in the greenhouse by direct plant spraying under a randomized block design; in both designs, a control without NPs was added. Mortality was recorded every 24 h for 4 days. Both NPs in the laboratory and greenhouse showed toxicity to B. cockerelli nymphs. Results in the laboratory showed that NPs significantly caused increased mortality of 88, 99, and 100% 96 h after treatment of ZnO NPs, TiO2 NPs, and their combinations, at 1000, 100, and 250 ppm, respectively. Direct spray of plants in the greenhouse showed low mortality with 27, 32, and 23% after 96 h of ZnO NPs, TiO2 NPs, and their combinations, at 3000, 500, and 250 ppm, respectively. These results on B. cockerelli control seem promising. Nanoparticles as insecticides are a novel strategy, however, further investigation is required in field tests to obtain suitable efficacy for use in a pest management system