Experimental modeling of colour harmony

This study investigates colour harmony in visual experiments in order to develop a new quantitative colour harmony model. On the basis of new experimental results, colour harmony formulae were developed to predict colour harmony from the CIECAM02 hue, chroma, and lightness correlates of the members of two‐ or three‐colour combinations. In the experiments, observers were presented two‐ and three‐colour combinations displayed on a well‐characterized CRT monitor in a dark room. Colour harmony was estimated visually on an 11 category scale from ?5 (meaning completely disharmonious) to +5 (meaning completely harmonious), including 0 as the neutral colour harmony impression. From these results, mathematical models of colour harmony were developed. The visual results were also compared with classical colour harmony theories. Two supplementary experiments were also carried out: one of them tested the main principles of colour harmony with real Munsell colour chips, and another one compared the visual rating of the new models with existing colour harmony theories. © 2009 Wiley Periodicals, Inc. Col Res Appl, 2010.     

Characterization of Soybean Proteins–Fatty Acid Systems

This study investigated, with the aim of obtaining more flexible and hydrophobic proteins, the attachment of a low chain fatty acid, decanoic acid, to alkaline and acid soybean proteins; and the effect on their conformational and functional properties. The extent of esterification was high at acid pH and also increased with heating. Protein solubility decreased, mainly at the highest temperature (60 °C). Increasing levels of fatty acid formed a complex with a slightly more soluble protein with less surface hydrophobicity. Esterified proteins exhibited aggregation/dissociation and were stabilized by different protein subunits belonging to 7S and 11S globulins. Denaturation of these soybean protein fractions (7S and 11S) were also detected in these complexes. The highest level of fatty acids favored formation of a more ordered protein structure.     

Effect of fermentation temperature on microbial population evolution using culture-independent and dependent techniques

The population dynamics of micro-organisms during grape-must fermentation has been thoroughly studied. However, the main approach has relied on microbiological methods based on plating. This approach may overlook micro-organisms that (i) grow slowly or do not grow well on artificial media or (ii) whose population size is small enough to be detected by regular sampling. Culture-independent methods have been used and compared with the traditional plating method during wine fermentations performed at two different temperatures (13 °C and 25 °C). These methods include a qualitative technique, the DGGE; a semi-quantitative technique, the direct cloning of amplified DNA; and a quantitative technique, the QPCR. The biodiversity observed in the must and at the beginning of fermentation was much higher when DGGE or direct cloning were used. Quantification of the most frequent non-Saccharomyces yeast, Hanseniaspora uvarum and Candida zemplinina, showed that they survived throughout the fermentation process and, specifically, it revealed the quantitatively relevant presence of C. zemplinina until the end of fermentation.     

Effect of Temperature on the Viscosity of Honey

Influence of temperature on the viscosity of honeys was analysed in the present work. The viscosity value decreased with the increase of temperature. The effect caused by temperature in the range studied was more important in the low range of temperature, whereas at high temperature, the viscosity showed less variation. Water activity and glass transition temperature was determined to relate these characteristics. Four experimental viscosity models were checked using the experimental data to correlate the influence of temperature upon honey viscosity.     

Evaluation of a hydrothermal process for pretreatment of wheat straw—effect of particle size and process conditions

BACKGROUND: Hydrothermal processes are an eco‐friendly processes that provide an interesting alternative for chemical utilization of lignocellulosic materials, in which water and crop residues are the only reagents. In this work the effect of process conditions (size distribution of the wheat straw, temperature and time) was evaluated against production of fermentable products. RESULTS: The use of milled wheat straw fractions as a raw material containing blends of different particle size distribution showed that the latter had an influence on the final sugars in the hydrolysate. Improved values of glucose (21.1%) and xylose yields (49.32%) present in the hydrolysate were obtained with treatment severity factors of 2.77 and 3.36, respectively. Mathematical models were developed aimed at establishing the effect of process conditions on monosaccharide concentration and its degradation in the liquor. CONCLUSION: This work shows that the use of wheat straw blends with various particle sizes has a significant effect on the extraction of fermentable products. The effect of treatment severity, which takes into account both processing time and temperature was also evaluated. These results are of importance for process design. Copyright © 2010 Society of Chemical Industry     

Hypolipidemic effects of proanthocyanidins and their underlying biochemical and molecular mechanisms

Proanthocyanidins are the most abundant polyphenols in human diets. Epidemiological studies strongly suggest that proanthocyanidins protect against cardiovascular diseases. Despite the antioxidant and anti‐inflammatory properties of these flavonoids, one of the mechanisms by which proanthocyanidins exert their cardiovascular protection is improving lipid homeostasis. Animal studies demonstrate that proanthocyanidins reduce the plasma levels of atherogenic apolipoprotein B‐triglyceride‐rich lipoproteins and LDL‐cholesterol but increase antiatherogenic HDL‐cholesterol. The results in humans, however, are less clear. This review summarizes the results that have been published on plasma triglyceride, apolipoprotein B, HDL‐cholesterol and LDL‐cholesterol levels in humans and animal models in response to proanthocyanidin extracts and proanthocyanidin‐rich foods. The physiological processes and biochemical pathways that are related to lipid homeostasis and affected by proanthocyanidin consumption are also discussed. Intestinal lipid absorption, chylomicron secretion by the intestine and VLDL secretion by the liver are the processes that are most repressed by proanthocyanidins, which, therefore, induce hypolipidemic effects.