Relationship between wine composition and temperature: Impact on Bordeaux wine typicity in the context of global warming—Review

Weather conditions throughout the year have a greater influence than other factors (such as soil and cultivars) on grapevine development and berry composition. Temperature affects gene expression and enzymatic activity of primary and secondary metabolism which determine grape ripening and wine characteristics. In the context of the climate change, temperatures will probably rise between 0.3°C and 1.7°C over the next 20 years. They are already rising and the physiology of grapevines is already changing. These modifications exert a profound shift in primary (sugar and organic acid balance) and secondary (phenolic and aromatic compounds) berry metabolisms and the resulting composition of wine. For example, some Bordeaux wines have a tendency toward reduced freshness and a modification of their ruby color. In this context it is necessary to understand the impact of higher temperatures on grape development, harvest procedures, and wine composition in order to preserve the typicity of the wines and to adapt winemaking processes.     

Influence of cultivar,storage and cooking on the mechanical properties of winter squash (Cucurbita maxima)

Texture profile analysis and rupture tests were carried out on raw and cooked tissues of ‘Delica’, ‘CF 2’ and ‘CF 4’ buttercup squash cultivars and ‘Red Warren’ pumpkin during storage. The raw tissues of ‘CF 2’ were the firmest, exhibiting high tissue strength (high failure force) combined with less rigidity, ie lower modulus of deformability (MOD) and higher compressibility (high strain and deformation at failure). ‘Red Warren’ had the least firm tissues combined with high rigidity and low compressibility. The firmness of ‘Delica’ and ‘CF 4’ tissues was intermediate. The texture parameters such as MOD, failure force, hardness, gumminess and chewiness measured on raw and cooked tissues of the four cultivars showed no significant differences up to 2 months of storage but then decreased (P < 0.05) between 2 and 3 months of storage. The size of the cells and thickness of the parenchyma cell walls among ‘Delica’, ‘CF 2’ and ‘CF 4’ were similar. The greater size of ‘Red Warren’ parenchyma cells, larger intercellular spaces and thinner cell walls appear to account for its lower tissue strength compared with the other cultivars. Copyright © 2004 Society of Chemical Industry     

Hydrophobic and Electrostatic Interactions on Extrusion of Protein Isolates

Lung protein isolates previously defatted by solvents of increasing polarity were extruded. Water monolayer values of these isolates, calculated from water vapor isotherms, showed a maximum when solvents of intermediate polarity were used. Shear resistance of the extruded products presented a similar behavior, with maximum values attained when the same solvents were employed to defat the isolates prior to extrusion. Phospholipid percentage in lipid fraction of the solvent extracts showed that minimum phospholipids were removed from the isolates when these solvents were used. The results suggested that the presence of phospholipid in the isolates after defatting could be important in improving the extrusion of these systems. Hydrophobic and electrostatic interactions between the macromolecules involved seemed therefore, to be relevant for the final texture obtained by extrusion.     

Supercritical gas extraction of Victorian brown coals: The effect of coal properties

A selection of fifteen Victorian brown coals, which varied in lithotype but only slightly in rank, were subjected to supercritical gas extraction with toluene. Seven of these coals were also extracted with 5% tetralin/toluene under the same conditions of temperature and pressure (400 °C and 10 MPa). The overall conversion, the extract yield and the yield of toluene solubles (oil and asphaltene) were correlated with more easily obtained coal properties using simple linear regression analysis. Good correlations were obtained between the total conversions and the volatile matter content of the coals, and for the toluene extractions between both the extract yield and the yield of toluene solubles and the H/C atomic ratio. For the toluene solubles from the toluene extractions, the aromaticity decreased and the molecular weight increased as the H/C atomic ratio of the coal increased. Inorganic constituents of the coals did not appear to have a marked effect on total conversion and liquid yields. Removal of the cations from two coals increased conversion and liquid yields in one case and decreased these in the other, but in both instances the changes were not large.     

Maintenance procedures and definition of limit states for exterior wood coatings

Maintenance procedures of different wood coating systems were studied in field exposure trials with coated balcony constructions. Maintenance coatings were applied on one half of each of the balcony parts after 18 months and assessed after 24 months of total exposure time. It was found that the opaque white coating systems were the most durable ones reaching long intervals of required maintenance. For systems with lower durability on the maintained surfaces further degradation of the coatings was prevented. Different characteristics were observed for film forming and non film forming semi-transparent varnishes. Definitions of a series of limit states for coating systems on wood were suggested including esthetical limits and three levels of durability limits. Film forming coatings can reach two durability limits, i.e. the maintenance interval and the renovation interval. For non film forming coatings there is only one limit state of coating durability where maintenance is needed. The third durability limit is related to the coated substrate, i.e. the wood component, by the onset of decay in wood.     

Determination of <Emphasis Type="Italic">Bacillus cereus</Emphasis> Emetic Toxin in Food Products by Means of LC–MS²

Cereulide is the heat-stable toxin produced by certain strains of Bacillus cereus. It is the main virulence factor of emetic B. cereus strains, which causes the emetic food poisoning syndrome, including rare fatal cases of food intoxications. Due to presumably low intoxication doses, a sensitive, specific, and robust technique is needed for its detection. In 2002, a LC–MS method was developed which allowed absolute quantification of cereulide using valinomycin as standard. This study describes the validation, according to the Commission Decision 2002/657/EC, of the LC–MS2 method, a tandem mass spectrometry technique, which guarantees lower detection limit and higher specificity. The LC–MS2 method, calibrated with valinomycin, was validated in rice and tested on various matrices (i.e., red beans, spices, and chili con carne) containing cereulide. The process combines a simple extraction step from the food matrix followed by LC–MS2 analysis and detection by ion trap mass spectrometer. The detection limit for cereulide in rice was 0.5 ng eq/g, which is 20 to 2,500 times lower than currently understood intoxicative doses between 10 and 1.280 ng/g previously reported for cereulide. The validated method was specific, sensitive, repeatable, and reproducible with recoveries ranging from 77% to 101%.