Prediction of migration fat bloom on chocolate

The objective of this study was to investigate whether it is possible to predict migration fat bloom based on measurements shortly after production. At different storage times shortly after production (0, 1, 4 h), the chocolate batches, varying in tempering method, tempering degree and amount of added butter oil, were evaluated by DSC, pNMR and texture analysis. Discriminant analysis and principal component analysis were combined to investigate the potential towards prediction. The batches were classified into groups depending on the time when white spots appeared (<8 wk, 8–13 wk, >13 wk). A good separation (100% correct classifications, 100% using cross‐validation) was obtained using the afore‐mentioned analyses and storage times. It was also shown that it is possible to exclude DSC analyses or analyses at 0 h storage time without compromising the classification performances too drastically. The study further elucidated that the tempering method has no significant effect on visual fat bloom development. Furthermore, undertempered chocolates bloomed quicker than well‐tempered ones, while fat bloom was delayed on overtempered chocolates. Addition of 6% butter oil promoted fat bloom development, while no significant difference was detected between chocolate with no added butter oil and chocolate with 3% butter oil added.     

Housing indicators in europe,a tool for housing research and housing policy?

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Housing indicators in europe, a tool for housing research and housing policy?     

Controlling the morphology of nanofiber-P3HT:PCBM blends for organic bulk heterojunction solar cells

Within the field of organic bulk heterojunction solar cells, the morphology of the active layer has a key role in obtaining high power conversion efficiencies. P3HT nanofibers, obtained in highly concentrated solutions, are able to give controlled morphologies directly upon deposition. Since the solar cell efficiency of fiber solar cells depends on the fiber content of the casting solution, it is important to control this parameter. Here, we demonstrate an easy way to control the fiber content in the casting solution, i.e. changing the solution temperature. By using solution heating, the overall molecular weight of the polymer in the blend is kept constant, fiber isolation is not needed and the use of solvent mixtures is avoided. The obtained optimal power conversion efficiency is shown to be linked to the morphology of the active layer, which is studied with Transmission Electron Microscopy (TEM).     

Joint kinematics and kinetics of overground accelerated running versus running on an accelerated treadmill

Literature shows that running on an accelerated motorized treadmill is mechanically different from accelerated running overground. Overground, the subject has to enlarge the net anterior–posterior force impulse proportional to acceleration in order to overcome linear whole body inertia, whereas on a treadmill, this force impulse remains zero, regardless of belt acceleration. Therefore, it can be expected that changes in kinematics and joint kinetics of the human body also are proportional to acceleration overground, whereas no changes according to belt acceleration are expected on a treadmill. This study documents kinematics and joint kinetics of accelerated running overground and running on an accelerated motorized treadmill belt for 10 young healthy subjects. When accelerating overground, ground reaction forces are characterized by less braking and more propulsion, generating a more forward-oriented ground reaction force vector and a more forwardly inclined body compared with steady-state running. This change in body orientation as such is partly responsible for the changed force direction. Besides this, more pronounced hip and knee flexion at initial contact, a larger hip extension velocity, smaller knee flexion velocity and smaller initial plantarflexion velocity are associated with less braking. A larger knee extension and plantarflexion velocity result in larger propulsion. Altogether, during stance, joint moments are not significantly influenced by acceleration overground. Therefore, we suggest that the overall behaviour of the musculoskeletal system (in terms of kinematics and joint moments) during acceleration at a certain speed remains essentially identical to steady-state running at the same speed, yet acting in a different orientation. However, because acceleration implies extra mechanical work to increase the running speed, muscular effort done (in terms of power output) must be larger. This is confirmed by larger joint power generation at the level of the hip and lower power absorption at the knee as the result of subtle differences in joint velocity. On a treadmill, ground reaction forces are not influenced by acceleration and, compared with overground, virtually no kinesiological adaptations to an accelerating belt are observed. Consequently, adaptations to acceleration during running differ from treadmill to overground and should be studied in the condition of interest.     

Automated image analysis tool for migration fat bloom evaluation of chocolate coated food products

Migration fat bloom remains a major problem in the production of coated confectionary products where a layer of chocolate is added around a filling or other fat containing substrate. Fat bloom quantification is typically done by a human panel scoring samples in time using a low resolution discrete scale. In view of developing a mechanistic model for migration fat bloom, it is important to have a higher resolution. In this paper, a new, high resolution quantitative method based on image analysis is developed. The method is able to detect both the evolution of fat bloom in terms of the disappearance of gloss and the development of “whitish” portions at the chocolate surface. It was successfully applied to distinguish the difference in fat bloom development rate between samples containing different fat concentrations (0, 3 and 6g/100g) coated on fillings containing different amounts of fat (25 and 75g/100g). In the 25g/100g filling fat case, blooming occurred at a very late stage and was caused by the disappearance of gloss. In the 75g/100g filling fat case the development of a “whitish” surface was responsible for the change in acceptability. The newly developed image analysis method is a solid alternative for the panel procedure.     

Development of a rheological method to characterize palm oil crystallizing under shear

To follow palm oil crystallization under shear, a new rheological method was developed. This method can be split up into two parts: In the first part, continuous shear is applied for a pre‐defined period and crystallization is monitored by measuring the apparent viscosity as a function of isothermal time under shear. In the second part, shear is halted and oscillation is applied during 30 s, thus recording moduli and phase angle. These moduli and phase angle are then characteristic of a sample crystallized under shear during this pre‐defined period. After repeating this procedure for increasing shearing periods in the first part, complex modulus and phase angle were plotted as a function of isothermal time under shear. The thus obtained results were compared with crystallization data obtained via time‐resolved X‐ray diffraction and polarized light microscopy.     

Towards a more effective and reliable salt crystallization test for porous building materials: state of the art

The durability of building materials with respect to salt crystallization is commonly determined by accelerated weathering tests, carried out in the laboratory. An effective laboratory weathering test should assess the durability and, in the case of conservation of historic buildings, the compatibility of repair materials with those existing. Besides, the test should provide reliable results within a reasonable period of time, accelerating the deterioration process without however altering its mechanism. Despite several national and international standards, recommendations and guidelines, a commonly accepted testing protocol does not yet exist. Researchers often develop and apply their own procedure, a fact that complicates comparison between different studies. The RILEM Technical Committee 271 ASC has been set up with the scope of developing improved test procedures for the assessment of the behaviour of materials under the influence of salt crystallization, which should overcome the limitations of existing standards and recommendations. This paper constitutes one of the first results of the work of the Technical Committee. It critically reviews the literature on salt crystallization tests, identifies advantages and limitations of the several test protocols and provides new ideas for the development of improved salt crystallization procedures.     

Trouble in paraside? On increasing housing problems in flanders

The survey data for this article was collected by the Center for Social Policy (Antwerp University). At regular intervals, they question a representative number of Belgian families in order to make the operation and effects of social policy measurable. On the basis of that data, this article traces the evolution of housing indicators in Flanders, the Dutch-speaking part of Belgium. After outlining the key issues in housing policy in Belgium and Flanders, the article presents the facts: for several population groups, it sketches the developments of tenure, housing amenities, housing costs, and affordability. The emerging picture is one of overall improvement. Nevertheless, some groups lag behind, while new social groups in need of housing emerge (e.g., lone parents). Age and the number of incomes per family seem to be the breaking points. The second part deals specifically with the housing situation of young families (head under 40 years of age). This population group is (historically) responsible for most new building of houses in Belgium and Flanders. Since we observe a decline in ownership, the reasons for this decline are of strategic importance to our understanding of the level of new housing construction and scarcity on the housing market. At the time of the research,Pascal De Decker (sociologist and urban planner) held an appointment at the Center for Housing and Housing Policy (Steunpunt voor Wonen en Woonbeleid) at Antwerp University (UFSIA). At present, he is an expert consultant to the Cabinet of the Flemish Minister for Urban Policy and Housing. Bert Meulemans (sociologist) supervised the reported research on target groups. He is a researcher at the Center for Social Policy (Centrum voor Sociaal Beleid) at Antwerp University (UFSIA) Veerle Geurts (criminologist) is a researcher at the Center for Housing and Housing Policy (Steunpunt voor Wonen en Woonbeleid) at Antwerp University (UFSIA)