Rheological behaviour of some amphiphilic β‐cyclodextrin‐based azo aromatic polyurethanes in N,N‐dimethylformamide solutions

Amphiphilic β‐cyclodextrin‐based azo aromatic poly(ether urethane)s with different soft segment lengths have been synthesized and characterized. Hydrogen bonding in these systems was demonstrated by Fourier transform infrared spectroscopy analysis (carbonyl stretching region). A rheological study was performed on solutions of the synthesized poly(ether urethane)s in N,N‐dimethylformamide at various concentrations and temperatures by employing parallel plate geometry, and a comparative evaluation of the influence of the structural components on the viscometric responses was performed. The rheological behaviour was found to be strongly dependent on the chemical composition of the synthesized polyurethanes which promotes self‐assembly and structuring in solution. Hard segment content and polymer concentration influence pseudoplastic shear‐thinning flow behaviour. The rheology can be interpreted in terms of hydrophobic associations and chain entanglements and a hydrogen bonding network occurring in solution. The start‐up flow of the polymer solutions is determined by the lifetime of the associative polymer segments. Shear stress plateaux indicative of ‘shear banding’ behaviour explained by the structuring of the polymer solutions at increased temperatures were obtained. The studied amphiphilic polyurethane solutions are thermoresponsive systems exhibiting viscosity increase with increasing temperature contrary to the usual Arrhenius thermo‐thinning behaviour. At constant shear rate viscosity was found to increase with increasing temperature due to thermo‐association. © 2014 Society of Chemical Industry     

Enlargement of Submicron Gas‐Borne Particles by Heterogeneous Condensation for Energy‐Efficient Aerosol Separation

To improve the efficiency of aerosol separation, a process sequence for particle enlargement by condensation of water vapor on their surface is suggested. The presented method makes use of packed columns in non‐equilibrium operation to achieve supersaturation, which is required for droplet growth. Although this method is known for several years, it is not widely used in industrial processes and still needs accurate investigations for consolidation and establishment. The simulation tool AerCoDe3.0 for predicting saturation and particle growth in packed columns allows investigating the thermal energy consumption under various operation conditions. Based on the results obtained in this study, optimized arrangements of columns, which are applicable as preconditioning step for existing particle separators, are proposed.     

EZH2 Down-Regulation Exacerbates Lipid Accumulation and Inflammation in in Vitro and in Vivo NAFLD

Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent, chronic liver diseases, worldwide. It is a multifactorial disease caused by complex interactions between genetic, epigenetic and environmental factors. Recently, several microRNAs, some of which epigenetically regulated, have been found to be up- and/or down-regulated during NAFLD development. However, in NAFLD, the essential role of the Polycomb Group protein Enhancer of Zeste Homolog 2 (EZH2), which controls the epigenetic silencing of specific genes and/or microRNAs by trimethylating Lys27 on histone H3, still remains unknown. In this study, we demonstrate that the nuclear expression/activity of the EZH2 protein is down-regulated both in livers from NAFLD rats and in the free fatty acid-treated HepG2. The drop in EZH2 is inversely correlated with: (i) lipid accumulation; (ii) the expression of pro-inflammatory markers including TNF-α and TGF-β; and (iii) the expression of miR-200b and miR-155. Consistently, the pharmacological inhibition of EZH2 by 3-Deazaneplanocin A (DZNep) significantly reduces EZH2 expression/activity, while it increases lipid accumulation, inflammatory molecules and microRNAs. In conclusion, the results of this study suggest that the defective activity of EZH2 can enhance the NAFLD development by favouring steatosis and the de-repression of the inflammatory genes and that of specific microRNAs.     

Polydimethylsiloxanes Cross-Linked by 4,4′-(1,3-Phenylenedioxy)-Dianiline within in situ Generated Silica Network

Polydimethylsiloxanes side-functionalized in different degrees with chloromethyl groups were reacted with 4,4′-(1,3-phenylenedioxy)-dianiline when the secondary amino groups formation and cross-linking occur. The reactions were carried out in a silica sol-gel system and thus two networks are simultaneously formed: siloxane-organic network and the silica one. Different techniques were used to characterize the formed systems: FTIR to verify the structure, DMA for analysis of the thermomechanical behavior, SEM and AFM for the evaluation of the morphology and surface topography. The elemental distribution within the samples was determined by EDX. The water vapours sorption capacity was measured in the dynamic regime.     

STRUCTURAL CHANGES AND MASS TRANSFER DURING GLUCOSE INFUSION OF APPLES AS AFFECTED BY BLANCHING AND PROCESS VARIABLES

ABSTRACT

The effect of process variables and blanching on the rate of dewatering of apple slices through immersion in glucose solutions was analyzed. The adequacy of the Hawkes and Flink's and Peleg's models for fitting the rate data was evaluated as well as the structural changes produced in the tissue subjected to osmotic process. High concentration values (33-42 % (w/w)) of the soaking solution favored significantly water loss (WL) but only slightly affected solid gain (SG). Increasing system temperature over the range 20-50 °C generally provided an increase in WL and in SG. The increase in thickness decreased significantly both mass transfer rates. The use of sucrose instead of glucose lead to a greater SG while blanched samples showed higher rates of WL and SG. Microscopic studies revealed that, when applying short treatments, cells appeared slightly shrinked and cells walls folded. After long treatments, although an extensive     

Microencapsulation of passion fruit (Passiflora) juice with n-octenylsuccinate-derivatised starch using spray-drying

Food microencapsulation has been an efficient way of raising food shelf life during storage. In this work passion fruit juice was encapsulated with n-octenylsuccinate-derivatised starch using a spray-dryer and stored at two different temperatures. The shelf life of vitamin C was analysed and X-ray diffraction, scanning electronic microscopy and laser diffraction analyses were performed. Samples stored at 7 and 25 °C retained 77.1 and 71.5%, respectively, of vitamin C after 77 days of storage. Capsules had an average size of 12.5 μm and were presented in an amorphous form. n-Octenylsuccinate-derivatised starch showed to be an interesting material for the encapsulation of passion fruit juice, and spray-drying proved itself as an inexpensive alternative to freeze-drying, capable of retaining vitamin C during a long time of storage, and easy to be diluted in order to reconstitute the passion fruit juice for human consumption.     

Use of sesame oil cake (Sesamum indicum L.) on corn expanded extrudates

In the production of oil from sesame (Sesamum indicum L.) seeds, a coproduct is obtained which is rich in protein and fiber contents. Mixtures of semi-defatted sesame cake (SDSC) (0–20%) and corn grits were processed in a single screw extruder at screw speed ranging from 324 to 387 rpm to improve the nutritional value of corn expanded extrudates. Chemical composition of raw and extruded materials, sectional expansion index (SEI), texture properties, color, paste viscosity, microstructure and sensory analysis of the extrudates were performed. The addition of SDSC increased protein, fat and ash content of corn extrudates, whereas carbohydrate content was reduced. The addition of SDSC reduced the sectional expansion of the corn extrudates and increased puncture force. SDSC–corn extrudates were darker than non-SDSC–corn extrudates. Increasing SDSC increased the number of cells similar to those of commercial corn extrudates with small cells. Sensory analysis showed 20% SDSC-corn extrudates to be acceptable and nutritional balanced. The use of SDSC on corn extrudates up to 20% is an alternative to improve nutritional value keeping good sensory characteristics.     

Exposure assessment of food preservatives (sulphites, benzoic and sorbic acid) in Austria

An exposure assessment was performed to estimate the potential intake of preservatives in the Austrian population. Food consumption data of different population groups, such as preschool children aged 3-6 years, female and male adults aged 19-65 years were used for calculation. Levels of the preservatives in food were derived from analyses conducted from January 2007 to August 2010. Dietary intakes of the preservatives were estimated and compared to the respective acceptable daily intakes (ADIs). In the average-intake scenario, assuming that consumers randomly consume food products that do or do not contain food additives, estimated dietary intakes of all studied preservatives are well below the ADI for all population groups. Sulphite exposure accounted for 34%, 84% and 89% of the ADI in preschool children, females and males, respectively. The mean estimated daily intake of benzoic acid was 32% (preschool children), 31% (males) and 36% (females) of the ADI. Sorbic acid intakes correspond to 7% of the ADI in preschool children and 6% of the ADI in adults. In the high-intake scenario assuming that consumers always consume food products that contain additives and considering a kind of brand loyalty of consumers, the ADI is exceeded for sulphites among adults (119 and 124%, respectively). Major contributors to the total intake of sulphites were wine and dried fruits for adults. Mean estimated dietary intakes of benzoic acid exceeded the ADI in all population groups, 135% in preschool children, 124% in females and 118% of the ADI in males, respectively. Dietary intakes of sorbic acid are well below the ADI, accounting for a maximum of 30% of the ADI in preschool children. The highest contributors to benzoic and sorbic acid exposure were fish and fish products mainly caused by high consumption data of this large food group, including also mayonnaise-containing fish salads. Other important sources of sorbic acid were bread, buns and toast bread and fruit and vegetable juices.     

Impact of cell spreading on second-life of lithium-ion batteries

The evolution of the degradation paths of the cells in battery packs is shaped by both intrinsic cell-to-cell variations, also known as cell spreading, and spatial–temporal cell-to-cell differences in temperature and other stress factors. To account for these variations and differences in degradation, we propose a statistical approach for modelling the degradation of lithium-ion batteries (LIBs) that utilizes a three-parameter non-homogeneous gamma process, allowing for the prediction of the capacity fade or time-to-failure for any LIB architecture. This degradation modelling approach has been integrated into a cost model to investigate the sensitivity of the battery lifetime's economic outcome, aiming to maximize the added value of stationary battery storage composed of degraded electric vehicle batteries. Thus, the impact of cell spreading was quantified for three simulation scenarios on second-life applications: (i) performing a simplified cost analysis to evaluate the business case for second-life, (ii) performing an economic analysis to visualize the impact of spreading, and (iii) evaluating an existing power flow control strategy between LIB modules. The information derived from the spreading-cost integration approach is valuable to support the technical and economic analyses in the decision-making process of designing, installing, and running efficiently second-life applications.