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Biodegradable and antioxidant films based on methylcellulose (MC) and α-tocopherol nanocapsule suspension (NCs) were developed. MC and NCs films were prepared by a casting method in three different proportions. The mechanical, wettability, colour, light transmission, antioxidant and release characteristics of the films were studied. The addition of NCs to MC films decreased the tensile strength (TS) and the elastic modulus (EM) (p<0.05) but increased the percentage elongation at break (%E) and thickness (p<0.05). NCs films showed a higher hydrophobicity when compared to that of film control. Lightness and yellowish color were intensified in the NCs films which, in their turn, demonstrated high antioxidant activity and excellent barrier properties against UV and visible light. A burst and prolonged release of α-tocopherol to food simulant was also reported.

All lactic beverages were considered probiotics. The addition of prebiotic resulted in beverages with higher total solids and total carbohydrates contents, without changing the other physicochemical parameters, including the attributes of colour. All beverages showed non-Newtonian behaviour, with shear thinning characteristics and presence of thixotropy, which is less accentuated in beverages with oligofructose. In these beverages, there was a decrease in apparent viscosity, consistency index and activation energy, and an increase in flow index and frequency factor. The beverages with oligofructose were sensory preferred in relation to the control, also showing good overall acceptability and most judges indicated that they would buy such a product.

Barley is rarely used in the food industry, even though it is a main source of β-glucans, which have important health benefits and a technological role in food. This work evaluated the humid extraction of barley β-glucans and partially characterized them. The extraction was studied using surface response methodology with both temperature and pH as variables. The extracted β-glucans were characterized by chemical and rheological analysis, infrared spectroscopy and scanning electron microscopy. The effect on extraction of linear and quadratic terms of pH and temperature corresponding to the regression model was significant, and we obtained a maximum concentration of 53.4% at pH 7.56 and temperature 45.5°C, with protein and mainly starch contamination. The extracted β-glucans presented a higher apparent viscosity than the commercial ones, the behavior of the commercial and extracted samples can be described as Newtonian and pseudoplastic, respectively. The results of infrared spectroscopy and scanning electron microscopy were characteristic of commercial β-glucans, indicating that this method is efficient for extracting β-glucans.

BackgroundUncoupling protein one (UCP1) is a mitochondrial inner membrane protein capable of uncoupling the electrochemical gradient from adenosine-5′-triphosphate (ATP) synthesis, dissipating energy as heat. UCP1 plays a central role in nonshivering thermogenesis in the brown adipose tissue (BAT) of hibernating animals and small rodents. A UCP1 ortholog also occurs in plants, and aside from its role in uncoupling respiration from ATP synthesis, thereby wasting energy, it plays a beneficial role in the plant response to several abiotic stresses, possibly by decreasing the production of reactive oxygen species (ROS) and regulating cellular redox homeostasis. However, the molecular mechanisms by which UCP1 is associated with stress tolerance remain unknown.ResultsHere, we report that the overexpression of UCP1 increases mitochondrial biogenesis, increases the uncoupled respiration of isolated mitochondria, and decreases cellular ATP concentration. We observed that the overexpression of UCP1 alters mitochondrial bioenergetics and modulates mitochondrial-nuclear communication, inducing the upregulation of hundreds of nuclear- and mitochondrial-encoded mitochondrial proteins. Electron microscopy analysis showed that these metabolic changes were associated with alterations in mitochondrial number, area and morphology. Surprisingly, UCP1 overexpression also induces the upregulation of hundreds of stress-responsive genes, including some involved in the antioxidant defense system, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione-S-transferase (GST). As a consequence of the increased UCP1 activity and increased expression of oxidative stress-responsive genes, the UCP1-overexpressing plants showed reduced ROS accumulation. These beneficial metabolic effects may be responsible for the better performance of UCP1-overexpressing lines in low pH, high salt, high osmolarity, low temperature, and oxidative stress conditions.ConclusionsOverexpression of UCP1 in the mitochondrial inner membrane induced increased uncoupling respiration, decreased ROS accumulation under abiotic stresses, and diminished cellular ATP content. These events may have triggered the expression of mitochondrial and stress-responsive genes in a coordinated manner. Because these metabolic alterations did not impair plant growth and development, UCP1 overexpression can potentially be used to create crops better adapted to abiotic stress conditions.

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