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排序方式: 共有511条查询结果,搜索用时 15 毫秒
91.
Roeland Rombaut John Van Camp & Koen Dewettinck 《International Journal of Food Science & Technology》2006,41(4):435-443
Phospho‐ and sphingolipids (SPHs) were monitored upon processing of raw milk into skimmed milk, cream, butter, buttermilk, fresh cheese, acid whey, anhydrous milk fat and butterserum (=the aqueous phase of butter). These products were analysed on polar lipids, fat and dry matter and corresponding balances were calculated. It was found that polar lipids were preferentially enriched in aqueous phases like skimmed milk, buttermilk and butterserum. Significant differences in relative SPH content were observed. Tangential filtration and thermocalcic aggregation of the acid whey successfully recovered the polar lipids. With 11.5% of polar lipids on a dry matter base, representing 28.4% of the milk polar lipids and only 0.9% of the milk mass, butterserum was found to be most suitable for further purification. This could result in a food (ingredient) with enhanced technological and nutritional properties, as recent studies reveal health‐improving capacities of phospho‐ and SPHs. 相似文献
92.
Imogen Foubert Peter A. Vanrolleghem Bert Vanhoutte Koen Dewettinck 《Food research international (Ottawa, Ont.)》2002,35(10):945-956
A new model able to describe the kinetics of isothermal crystallization is presented: it is a model written in the form of a differential equation allowing use under dynamic temperature variations. It describes the crystallization process as if it is a reversible reaction with a first order forward reaction and a reverse reaction of order n. The model has the advantage of having an analytical solution under isothermal conditions that facilitates parameter estimation. The quality of this model was compared with the more traditional Avrami (with and without induction time) and Gompertz models using different model selection criteria. To show the universality of the model, different fat samples, different crystallization temperatures and different measuring techniques were used for model evaluation. The new model was selected as the best for the majority of the samples and this independent of the model selection criterion used. 相似文献
93.
Terzano R Spagnuolo M Vekemans B De Nolf W Janssens K Falkenberg G Fiore S Ruggiero P 《Environmental science & technology》2007,41(19):6762-6769
The major geochemical forms of Cr, Ni, Cu, Zn, Pb, and V in a soil from an industrial polluted site in the south of Italy were determined by means of synchrotron X-ray microanalytical techniques such as coupled micro-X-ray fluorescence/micro-X-ray diffraction and micro-X-ray absorption near edge structure spectroscopy in combination with bulk extraction methods (sequential extraction procedures, EDTA extractions, and toxicity leaching characteristic procedure tests). Cr, Ni, Zn, and Cu were found in spinel-type geochemical forms (chromite, trevorite, franklinite, zincochromite, and cuprospinel) and often in association with magnetite and hematite. Vwas mainly present as V(V) associated with iron-oxides or in the form of volborthite [Cu3(OH)2V2O7.2H2O]. Pb was speciated as minium (Pb3O4), lanarkite [Pb2O(SO4)], and, in association with Cr(VI), as crocoite (PbCrO4). In general, despite a high total concentration, metals appear to be speciated for the most part as rather insoluble geochemical forms. However, particular attention should be paid to Zn, Cu, V, and Pb that show non-negligible mobilizable fractions. On the basis of the geochemical forms identified, among others, two major former industrial activities were tentatively ascribed as being responsible for the observed major pollution: polyvinyl chloride and cement-asbestos productions. 相似文献
94.
Leonie Vogt Diederick Meyer Gerdie Pullens Marijke Faas Maaike Smelt Koen Venema 《Critical reviews in food science and nutrition》2015,55(3):414-436
Beneficial effects of inulin-type fructans are discussed in view of studies that applied the oligosaccharides in colon cancer, chronic inflammatory diseases, vaccination efficacy, and prevention of infection and allergy. In the present paper, we discuss their immunomodulating effects. It is suggested that immunomodulation is elicited through indirect and direct mechanisms. Indirect mechanisms encompass stimulation of growth and activity of lactic acid bacteria, but can also be caused by fermentation products of these bacteria, i.e., short chain fatty acids. Evidence for direct effects on the immune system generally remains to be confirmed. It is suggested that inulin-type fructans can be detected by gut dendritic cells (DCs), through receptor ligation of pathogen recognition receptors (PRRs) such as Toll-like receptors, nucleotide oligomerization domain containing proteins (NODs), C-type lectin receptors, and galectins, eventually inducing pro- and anti-inflammatory cytokines. DCs may also exert antigen presenting capacity toward effector cells, such as B cells, T cells, and natural killer cells locally, or in the spleen. Inulin-type fructans may also ligate PRRs expressed on gut epithelium, which could influence its barrier function. Inulin-type fructans are potent immunomodulating food components that hold many promises for prevention of disease. However, more studies into the mechanisms, dose-effect relations, and structure-function studies are required. 相似文献
95.
Nicolas Gryson Kathy Messens Koen Dewettinck 《Journal of the science of food and agriculture》2004,84(11):1357-1363
A method is described to discriminate between genetically modified (GM) and non‐modified foodstuffs by detecting the presence of newly introduced genes at the protein or DNA level. Currently available methods operate almost exclusively at the DNA level and are based on the polymerase chain reaction (PCR). The first and most crucial step in this process is the isolation of DNA. In this study, five different methods for the isolation of DNA from chocolate and biscuits were evaluated, using four commercially available extraction kits and a non‐commercial method for amplification of the soybean‐specific lectin gene. The latter method involves the use of hot‐start Taq polymerase, to prevent the formation of non‐specific amplification products, and an increase in the number of cycles from 35 to 41. The performance of the non‐commercial cetyl trimethylammonium bromide (CTAB)‐based method was the best, taking into consideration the adaptations of the extraction procedure, although this method was more time‐consuming than the others. Chocolate (white, milk and dark) and several biscuits generated positive amplification results using this PCR approach. Copyright © 2004 Society of Chemical Industry 相似文献
96.
Villani K Vermandel W Smets K Liang D van Tendeloo G Martens JA 《Environmental science & technology》2006,40(8):2727-2733
Platinum metal was dispersed on microporous, mesoporous, and nonporous support materials including the zeolites Na-Y, Ba-Y, Ferrierite, ZSM-22, ETS-10, and AIPO-11, alumina, and titania. The oxidation of carbon black loosely mixed with catalyst powder was monitored gravimetrically in a gas stream containing nitric oxide, oxygen, and water. The carbon oxidation activity of the catalysts was found to be uniquely related to the Pt dispersion and little influenced by support type. The optimum dispersion is around 3-4% corresponding to relatively large Pt particle sizes of 20-40 nm. The carbon oxidation activity reflects the NO oxidation activity of the platinum catalyst, which reaches an optimum in the 20-40 nm Pt particle size range. The lowest carbon oxidation temperatures were achieved with platinum loaded ZSM-22 and AIPO-11 zeolite crystallites bearing platinum of optimum dispersion on their external surfaces. 相似文献
97.
98.
99.
Jeroen Vereecken Imogen Foubert Kevin W. Smith Gary J. Sassano Koen Dewettinck 《European Journal of Lipid Science and Technology》2010,112(2):233-245
In this study, the crystallization and melting properties of four different fat blends with the same saturated fat content (30%) but with different ratios of symmetric and asymmetric monounsaturated triacylglycerols were investigated using pNMR, DSC and polarized light microscopy. Blends were either palmitic (P) or stearic (S) based, and were combinations of SatOSat‐rich (Sat = saturated, O = oleic) and SatSatO‐rich vegetable oils with high‐oleic sunflower oil. The DSC results demonstrate that there was almost no difference in crystallization mechanism and crystallization rate between the two P‐based blends. Both blends showed a two‐step crystallization, which can be explained by polymorphism. Stop‐and‐return DSC results suggested an initial crystallization into an unstable polymorph followed by polymorphic transition during the crystallization. For the S‐based blends there was a clear difference between the SOS‐rich and the SSO‐rich blend, with a slower crystallization for the SSO‐rich blend. Possibly, this can be explained by fractional crystallization. The microstructure did not differ greatly between the blends. Directly after crystallization, the crystals of the SSO‐rich blend were slightly larger than the crystals of the SOS‐rich blend. 相似文献
100.
The purpose of this paper is to demonstrate the relationships between sustainable building design and occupant well-being. It starts with a definition of sustainable design and well-being, and focuses on the relationships between energy performance and occupant feedback. Methodologically it draws on detailed monitoring and surveys of 12 case study office buildings in the UK and India, and the paper uses the data to explore whether energy use and associated CO2 emissions are correlated to occupant satisfaction and comfort. The results demonstrate that increased energy use in the case study buildings is associated with increased mechanisation (e.g. centralised air conditioning) and reduced occupant control. This reduced control in turn is shown to relate to reduced occupant comfort and satisfaction. Finally, the paper reveals that the reported health conditions of occupants correlates strongly with their levels of satisfaction. The overall conclusion is that energy use in typical office buildings is inversely correlated with the well-being of the occupants: more energy use does not improve well-being. 相似文献