Energy‐dependent effects of resveratrol in Saccharomyces cerevisiae

The metabolic effects induced by resveratrol have been associated mainly with the consumption of high‐calorie diets; however, its effects with standard or low‐calorie diets remain unclear. To better understand the interactions between resveratrol and cellular energy levels, we used Saccharomyces cerevisiae as a model. Herein it is shown that resveratrol: (a) decreased cell viability in an energy‐dependent manner; (b) lessening of cell viability occurred specifically when cells were under cellular respiration; and (c) inhibition of oxygen consumption in state 4 occurred at low and standard energy levels, whereas at high energy levels oxygen consumption was promoted. These findings indicate that the effects of resveratrol are dependent on the cellular energy status and linked to metabolic respiration. Importantly, our study also revealed that S. cerevisiae is a suitable and useful model to elucidate the molecular targets of resveratrol under different nutritional statuses. Copyright © 2016 John Wiley & Sons, Ltd.     

Development of a real-time PCR method for the simultaneous detection of soya and lupin mitochondrial DNA as markers for the presence of allergens in processed food

Lupin and soya are members of the Leguminosae family which are recognised as some of the richest source of vegetable proteins. Lupin- and soya-containing products are available on the EU market and could cause severe adverse reactions in allergic individuals, even if consumed at low concentrations. In this context the development of methods for reliable detection of these allergens in food products is a useful tool for the surveillance of established legislation on food labelling within the EU. This work described the development of a duplex real-time PCR method allowing the simultaneous detection of traces of lupin and soya in processed food based on a specific TaqMan® probe designed on a mitochondrial tRNA-MET gene. A set of primers and probes was designed for the amplification of a 168 and 175 bp fragment of lupin and soya mitochondrial DNA, respectively. The performance of the method was established using lupin and soya flours and cookies baked from lupin- and soya-containing dough (different concentrations and baking times). The PCR platform yielded consistent and repeatable results. The specificity of the system was tested with DNA from 28 plant species. The sensitivity of the method was suitable to detect allergenic ingredients in the low mg per kg range. Both lupin and soya at a level of 2.5 mg per kg food matrix could be detected in cookies baked at 180 °C for 10 min. The method was successfully applied to bakery (e.g. bread) and vegetarian (e.g. non-meat sausages) food products that contain or may contain soya and/or lupin as ingredient or contaminant (according to the declaration on the product label).     

Physical Stability of Octenyl Succinate–Modified Polysaccharides and Whey Proteins for Potential Use as Bioactive Carriers in Food Systems

The high cost and potential toxicity of biodegradable polymers like poly(lactic‐co‐glycolic)acid (PLGA) has increased the interest in natural and modified biopolymers as bioactive carriers. This study characterized the physical stability (water sorption and state transition behavior) of selected starch and proteins: octenyl succinate–modified depolymerized waxy corn starch (DWxCn), waxy rice starch (DWxRc), phytoglycogen, whey protein concentrate (80%, WPC), whey protein isolate (WPI), and α‐lactalbumin (α‐L) to determine their potential as carriers of bioactive compounds under different environmental conditions. After enzyme modification and particle size characterization, glass transition temperature and moisture isotherms were used to characterize the systems. DWxCn and DWxRc had increased water sorption compared to native starch. The level of octenyl succinate anhydrate (OSA) modification (3% and 7%) did not reduce the water sorption of the DWxCn and phytoglycogen samples. The Guggenheim–Andersen–de Boer model indicated that native waxy corn had significantly (P < 0.05) higher water monolayer capacity followed by 3%‐OSA‐modified DWxCn, WPI, 3%‐OSA‐modified DWxRc, α‐L, and native phytoglycogen. WPC had significantly lower water monolayer capacity. All Tg values matched with the solid‐like appearance of the biopolymers. Native polysaccharides and whey proteins had higher glass transition temperature (Tg) values. On the other hand, depolymerized waxy starches at 7%‐OSA modification had a “melted” appearance when exposed to environments with high relative humidity (above 70%) after 10 days at 23 °C. The use of depolymerized and OSA‐modified polysaccharides blended with proteins created more stable blends of biopolymers. Hence, this biopolymer would be suitable for materials exposed to high humidity environments in food applications.     

Sooting behavior in temperature-controlled laminar diffusion flames

The sooting tendency of gaseous and liquid hydrocarbon fuels has been determined systematically in an axisymmetric laminar diffusion flame whose temperature was controlled by nitrogen dilution. Sooting tendency was measured by the minimum mass flow rate of fuel (FFM) at the smoke height. Result, plotted as log 1/FFM versus $\text{1}\text{T}$, where T is a calculated adiabatic flame temperature, show that fuel structure plays a significant role in diffusion flames. Comparison of these flame results with basic pyrolysis studies in the literature supports the concept that pyrolysis of the fuel molecule is a controlling factor in determining the overall tendency to soot, even though such tendency results from the competition of pyrolysis of the fuel and heterogeneous oxidation of the soot particles. The pyrolysis characteristics affecting the sooting process are rate, sequence and nature of products, and pyrolysis mode (pure or oxidative). The aromatics show a temperature sensitivity with respect to sooting tendency significantly lower than the other fuels. Conjugation of the initial fuel molecule and pyrolysis intermediates enhances sooting propensity.     

Probabilistic seismic damage assessment of reinforced concrete buildings considering directionality effects

Most of buildings and structures are usually projected according to two main axes. However, the geographical position of these buildings varies randomly. Such random distributions of the azimuthal positions of structures, in most of the cities, generally, are not accounted for when assessing their seismic risk; certainly, the direction of the seismic loads is another highly random variable. Moreover, an additional important source of uncertainty is related to the structural response, mainly due to the random character of the mechanical properties. There is a consensus that uncertainties must be considered for adequately assessing the seismic risk of structures, but these directionality effects have not been deeply explored so far. In this article, the influence of the high uncertainty involved in these input variables on the expected seismic damage is analysed. Thus, an actual earthquake, which affected the southern part of Spain, is studied. Notably, damages on a group of affected buildings, located close to the epicentre, are analysed and discussed in detail. The results show that the influence of the random azimuthal position of structures is an important source of uncertainty and that it should be taken into account when estimating the expected seismic risk in urban areas.     

Reviewing Rare Earth Succinate Frameworks from the Reticular Chemistry Point of View: Structures,Nets, Catalytic and Photoluminescence Applications

The intense development that Metal-Organic Frameworks have experienced along the last two decades, reflects the interest on these compounds as a new generation of multifunctional materials with diverse applications. The first works of Prof. Omar Yaghi devoted to obtain open frameworks by combining rigid aromatic linkers and a variety of metal centers, encouraged the creativity of the scientific community to designcoordination polymers employing aliphatic ligands as multitopic building blocks . Here, a revision of the literature dedicated to rare earth coordination networks mainly based in succinate ligand and derivatives is performed. A structural analysis of 2D and 3D frameworks based on rare earth elements and succinate, was carried out considering their inner connectivities and topologies with focus on those compounds with potential photoluminescent and catalytic technological applications. Thus, a variety of optical behaviours regarding the emission mechanisms, colours, lifetimes, quantum yields as well as chemical/thermal sensing properties are presented and compared with related phases found in literature. The catalytic performance of several rare earth-succinates in three important reactions is discussed in terms of their acidity, dimensionality and available active centers towards the formation of the desired products analysing parameters such as selectivity, yields and TOFs.