Authors:A. Bravo, L. Ponce, P. Párraga, R. Oliva, and K. Proaño
In this study we analyzed the performance of three wheat varieties in relation to gluten content under high-altitude growing conditions in the Andes of Ecuador. A field experiment was conducted at 3058 meters above sea level during 2009 using adapted wheat cultivar Cojitambo, cv. Carnavalero, and cv. Sibambe. Transcript accumulations of High Molecular Weight Glutenin Subunits (HMW-GS) genes were also evaluated during grain development using qRT-PCR. We recorded the expression profile of HMW-GS genes during 41 days and showed a coordinated pattern of induction with significant higher levels at 82–86 days. Transcript accumulation of 1Dx5, 1Dy10, 1Bx7, 1Ax1, and 1By9 genes were analyzed in more details during this period. The assay highlighted the specific contribution of 1Bx7, 1Dy10, and 1Dx5 during gluten formation in Ecuadorian wheat varieties. Under Andean highlands conditions, cv. Carnavalero showed the higher values of total agglomerated protein upon hydration and higher levels of expression of particular HMW-GS genes. The data suggest a correlation between wet gluten content and HMW-GS genes expression. Our study contributes to understand gluten formation in wheat endosperm under high-altitude conditions in the Andes.
Authors:I. Bravo-Osuna, A. Muńoz-Ruiz, M. Jiménez-Castellanos, J. Ford, and M. Whelan
The use of modulated temperature differential scanning calorimetry (TMDSC) and differential scanning calorimetry (DSC) in the measurement of the glass transition temperature (Tg) in polymer-water systems presents several important problems. These include the presence of water evaporation endotherms, partial water evaporation during scanning, changes in pan integrity due to vapour pressure developing in the pan headspace during analysis, and possible interaction between water and polymer at high temperatures. As a result, in most of the cases, only apparent Tg values can be obtained. In this study, TMDSC and DSC were used to determinate the thermal behaviour of methylmethacrylate copolymer-water systems. The samples were previously equilibrated at different relative humidities (RH) from 0 to 97% RH. Three different pan arrangements were used. In addition, thermogravimetric analysis (TG) was carried out to determine the initial amount of water in the sample. None of the pan arrangements was entirely suitable for the study of these systems. When sealed pans were used, the plastification effect of water was observed. Some evidence of degradation was also observed in which water and methylmethacrylate appeared to play roles.
Authors:L. Franco, R. Bravo, C. Galán, A.B. Rodríguez, C. Barriga, and Javier Cubero
Sleep deprivation affects the homeostasis of the physiological functions in the human organism. Beer is the only beverage that contains hops, a plant which has a sedative effect. Our objective is to determine the improvement of subjective sleep quality using the Pittsburgh Sleep Quality Index (PSQI). The sample was conducted among a population of 30 university students. The study took place during a period of 3 weeks, the first 7 days were used for the Control, and during the following 14 days the students ingested beer (were asked to drink non-alcoholic beer) while having dinner. The results revealed that Subjective Sleep Quality improved in the case of those students who drank one beer during dinner compared to the Control, this is corroborated by the fact that Sleep Latency decreased (p < 0.05) compared to their Control. The overall rating Global Score of Quality of Sleep also improved significantly (p < 0.05). These results confirm that the consumption of non-alcoholic beer at dinner time helps to improve the quality of sleep at night.
Authors:L. Franco, C. Sánchez, R. Bravo, A. Rodriguez, C. Barriga, and Javier Juánez
The hop (Humulus lupulus), a component of beer, is a sedative plant whose pharmacological activity is due principally to its bitter resins, especially to the α-acid component 2-methyl-3-buten-2-ol. The mechanism of action of the resin of hop consists of increasing the activity of the neurotransmitter γ-aminobutyric (GABA), inhibiting the central nervous system (CNS). Objectives: To analyze in an experimental model of diurnal animal the sedative effect of hop, a component of beer, on the activity/rest rhythm. Methods: Experiments were performed with common quail (Coturnix coturnix) similar to humans in the sleep-wake rhythm, isolated in 25 × 25 × 25 cm methacrylate cages, with food and water ad libitum, in a room with artificial ventilation (22 ± 1 °C) and a lighting cycle of 12L/12D (n = 5). The doses administered, close to the content of non-alcoholic beer, were 1, 2 and 11 mg extract of hop as one capsule per day, at 18:00 h for one week. A control group received capsules only with a methylcellulose excipient and a basal group received no treatment. The chronobiological analysis of the animals’ activity captured and logged by the software DAS24 was performed using the Ritme computer program (cosinor methods). Results: With the dose of 2 mg, there was a statistically significant (p < 0.05) reduction of the arithmetic mean nocturnal activity (23 ± 3.0) with respect to the basal (38.56 ± 2.79), control (38.1 ± 2.8) and other doses groups 1 mg (52.04 ± 3.65) and 11 mg (47.47 ± 5.88). This dose of 2 mg, similar to the concentration in beer, was more effective in reducing nocturnal activity than the other doses of 1 and 11 mg, as well as preserving the circadian activity/rest rhythm. Conclusion: The concentration of 2 mg of hop extract effectively decreased nocturnal activity in the circadian activity rhythm. On the basis of this investigation, administration of non-alcoholic beer would be recommended due to its hop content and consequent sedative action, which would be an aid to nocturnal sleep.