Antioxidant synergy of α-tocopherol and phospholipids

The prevention of oxidation of a refined sardine oil by α-tocopherol at 0.04%, by several phospholipids [phosphatidylcholine (PC), phosphatidylethanolamine (PE), and cardiolipin (CL)] at 0.5%, as well as by combinations of α-tocopherol with each phospholipid, was investigated. The evolution of the oxidation process during 1 mon at 40±2°C was followed by a series of methods, measuring peroxide value (PV), diene, triene, and polyene index, and absorbance at 430 nm, while α-tocopherol and phospholipid content were being monitoried. Among these indices, PV was found to be the most adequate to follow the process. PC was the most effective individual antioxidant as shown by the PV values obtained at the end of the storage period, which were 54.0, 83.4, 87.9, and 97.7 meq O₂/kg for PC, CL, PE, and α-tocopherol, respectively. The highest synergistic effect was obtained with a mixture of α-tocopherol and PE, and the second and third best by mixtures made with PC and CL, respectively. The corresponding PV values recorded at the end of the period were 27.0, 35.0, and 58.0 meq O₂/kg. The high degree of synergy between PE and tocopherol is probably due to the occurrence of a simultaneous antioxidant mechanism involving Maillard compounds.     

Optimisation of a continuous flash fermentation for butanol production using the response surface methodology

Factorial design and response surface techniques were used in combination with mathematical modelling and computational simulation to optimise an innovative industrial bioprocess, the production of biobutanol employing the flash fermentation technology. A parametric analysis performed by means of a full factorial design at two levels determined the influence of operating variables on butanol yield and productivity. A second set of simulations were carried out based on the central composite rotatable design. This procedure generated simplified statistical models that describe butanol yield and productivity as functions of the significant operating variables. From these models, response surfaces were obtained and used to optimise the process. For a range of substrate concentration from 130 to 180 g/l, the optimum operating ranges ensure butanol productivity between 7.0 and 8.0 g/l h, butanol yield between 19 and 22%, substrate conversion above 90% and final butanol concentration around 25 g/l.     

Enzymatic and molecular characteristics of Geotrichum candidum strains as a starter culture for malting

Geotrichum candidum yeasts are proposed as a starter culture during malting. They have a double positive effect on the process. They eliminate the fungal pathogenic microflora and improve the technological properties of the finished product, malt. Among published research little or no information can be found considering the biosynthesis of hydrolytic enzymes. Most of the data is related to the production of lipases, proteases and cellulases. This paper examines the enzymology of a number of G. candidum strains. The main focus within the evaluation process was placed on whole cell barley grain cultivation. Hydrolase, which is present in cell wall degradation, was found at a satisfactory level. All tested strains produced both β‐1,3‐glucanases and β‐1,4‐glucanases capable of hydrolysing barley β‐glucan and reducing the amount of this polysaccharide in the wort. Molecular analysis of the tested strains with the use of restriction fragment length polymorphism–polymerase chain reaction and randomly amplified polymorphic DNA confirmed not only the species affiliation, but also the genetic similarity between the tested strains. Copyright © 2014 The Institute of Brewing & Distilling     

Phase transformation and microstructural evolution after heat treatment of a terbium-doped lithium–aluminum phosphate glass

The crystallization kinetics and phase transformation of a transparent Tb³⁺-doped lithium–aluminum phosphate glass, prepared by melt quenching, were investigated. The energy associated to the glass transition and the crystallization parameters (activation energy for crystallization and Avrami exponent) were evaluated by different methods using the experimental data obtained by differential thermal analysis performed at different heating rates. Using an isoconversional method to determine the change of the activation energy for crystallization with the fraction of crystallization, it was verified that with the increase in the fraction of crystallization from 0.1 to 0.9, the value of the activation energy decreased slightly from ~370 to ~310 kJ mol^?1 and that the Avrami exponent varied from 0.8 to 1, suggesting a surface crystal growth mechanism. Observation of the microstructural evolution of heat-treated glass samples confirmed a surface crystallization process revealing spherulitic crystals constituted mainly by aluminum metaphosphate.     

Carbohydrate content of apolipoprotein B-48 from rat chylomicrons of varying density

Monosaccharide composition was determined in apolipoprotein B-48 (apoB) of chylomicrons of rat mesenteric lymph. Chylomicrons were separated into three fractions based on density. Triglyceride and apolipoprotein content were determined in each. ApoB was isolated and quantified using precipitation with isopropanol. Chylomicrons were collected in lymph under normal conditions, and with Poloxalene 2930 when chylomicron secretion was inhibited. Most of the triglyceride was carried in the least dense fraction, while the highest apoB content was in the most dense fraction under normal conditions. Mannose and galactosamine contents of apoB were similar in all fractions while contents of both glucosamine and galactose were highest in the least dense fraction. When chylomicron secretion was inhibited by Poloxalene, the amount of triglyceride recovered in the least dense fraction was significantly reduced. Despite the inhibition of lipid transport in the least dense fraction of chylomicrons by Poloxalene, there was little change in apoB recoveries and in the relative content of various monosaccharides in the apoB from each of the three fractions as compared to results obtained during lipid absorption under normal conditions. In conclusion, carbohydrate composition of apoB of chylomicrons is heterogeneous and varies with chylomicron density.     

Parental reports of coparenting and observed coparenting behavior during the toddler period.

Fifty-two married partners played with their 30-mo-olds in both dyadic (parent–child) and whole family contexts and reported on their own coparenting activities (family integrity-promoting behavior, conflict, disparagement, and reprimand). Coparenting behavior observed in the whole family context was evaluated for antagonism, warmth and cooperation, child–adult centeredness, balance of positive involvement, and management of toddler behavior. Parallel balance and management scores were also formed using dyadic session data. Men's reported family integrity-promoting activities and women's reported conflict and reprimand activities were reliable correlates of family group process in both bivariate and discriminant analyses, with links enduring even after controlling for marital quality. Whole family- and dyad-based estimates of coparenting were altogether unrelated, and reported coparenting was tied only to behavior in family context, not to family measures created from dyad-based data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automated Karl Fischer titration for liquid samples – Water determination in edible oils

In the field of food analysis, rapid measurements and results are generally of high importance. The Karl Fischer titration (KFT), a chemical method for determining water content, and its automated performance enhance rapidity by giving the opportunity to deal with more samples in less time; automated sequences can include different determination methods and sample treatments. Moreover, automation can improve reproducibility and precision.     

Functionally Graded Ceramics Fabricated with Side‐by‐Side Tape Casting for Use in Magnetic Refrigeration

Functionally graded ceramic tapes have been fabricated by a side‐by‐side tape casting technique. This study shows the possibility and describes the main principles of adjacent coflow of slurries resulting in formation of thin plates of graded ceramic material. Results showed that the small variations of solvent and binder system concentrations have a substantial effect on slurry viscosity. Varying these parameters showed that side‐by‐side tape casting with a well‐defined interface area is possible for slurries with viscosities above 3500 mPa s at a casting shear rate of 3.3 s^?1. As it was expected, the choice of de‐bindering and sintering regimes significantly influences crack formation, and a three‐step heating programme was found to result in tapes of the highest quality. The interface regions of green graded tapes were investigated structurally by scanning electron microscopy; for a distinct identification of the interface region and analysing the degree of cross‐interface diffusion, the isothermal entropy change was measured by a vibrating sample magnetometer as the magnetic transition temperature (Curie temperature) is very sensitive to the dopant level in ceramics. Also the purpose of developing this graded ceramic tape casting was applications of these specific magnetocaloric properties within the magnetic refrigeration technology.