In bread making the wheat dough undergoes some degree of deformation in each step of the process. It is generally accepted that the baking properties of wheat flour dough are mainly due to the viscoelasticity of the gluten protein. Measurement of the rheological properties of dough gives valuable information concerning the quality of the wheat flour, the machining properties of the dough and the textural characteristics of the finished products. This technique uses a new apparatus (wheat gluten quality analyser&WGQA, C HANG, 1994) especially developed to evaluate the rheological properties of gluten by measuring the following parameters: resistance to extension (newton), extensibility (mm) and energy (joule). The test realized with the apparatus WGQA was carried out on wheat gluten isolated according to the A.A.C.C. (1995) method. Results obtained using the new technique showed high levels of correlation for maximum resistance to extension (R 2 =0.9018) and energy (R 2 =0.8824) between WGQA and standardized parameters obtained from Brabender Extensograph.
Authors:C. Ferrari, G. Salvetti, E. Tognoni, and E. Tombari
The heat capacityCp of a sample can be considered as a frequency dependent quantity; its behaviour can reflect the dynamics of enthalpy fluctuations. In order to take into account the dynamic nature of the measured quantity, calorimetry can mimic experimental methods as those of dielectrometry, performing experiments in time domain or in frequency domain.
Authors:W. Blommaert, P. Ferrari, J. Culot, and C. Hurtgen
A survey is given of the main activities of the Belgoprocess Company, with special emphasis on safety precautions. The routine sampling program for internal contamination consists of urinary and faecal sampling, among others. Faecal samples sometimes reveal low contamination levels. This contamination can be considered as low-level, frequent, and intermittent. No distinct correlation is found with another control technique.A survey is given about uncertainties that might hamper a representative sampling and/or a correct interpretation of the obtained data. Reference is made to the dosimetric models regarding complexity and uncertainties.
Authors:G. Suber, M. Bertolotti, C. Sibilia, A. Ferrari, and F. Genel Ricciardiello
Transverse photothermal deflection spectroscopy(PDS) is applied for the determination of thermal diffusivities of solid surfaces. The theory of PDS is briefly recalled and some approximated analytical formulae concerning the transverse configuration are derived. In materials where the thermal diffusivity is smaller than that of the air, the dependence of the deflection angle on the displacement between pump and probe beams is shown to have a minimum that relates to the thermal diffusivity, thereby allowing its straightforward measurement. Measurements carried out on Al2O3 samples with different porosities at room temperature show a good agreement between experiment and theory.
Authors:M. Bertolotti, A. Ferrari, C. Sibilia, M. Tamburrini, F. J. Bordoni, and P. Jani
An interferometric method is described for the determination of small deformations of a solid surface when heated by a c.w. gaussian laser beam, from which temperature increase and thermal parameters can be derived. A discussion of the method is presented and applied to the measurement of thermal conductivity, for two different situations of an unrestrained or restrained sample heated with a c.w. laser. Experimental results are finally given for a semiconductor crystal of Si.
Authors:M. Kónya, M. Sorrenti, F. Ferrari, S. Rossi, I. Csóka, C. Caramella, G. Bettinetti, and I. Erős
Thermogravimetric and rheological investigations of oil/water (o/w) creams prepared with different types of surface-active
agents (non-ionic, non-ionic POE-free, ionic) were carried out. Thermogravimetry was aimed at the indirect study of the water
bond mechanism in o/w creams and the influence of the composition, type and concentration of the mixed emulsifier on the binding
of water incorporated in the structure (interlamellar, bulk) and on the binding proportions. The microstructural changes during
application were studied with respect to the stability of the lamellar bilayer.
Authors:M. Angiuli, C. Ferrari, L. Lepori, E. Matteoli, G. Salvetti, E. Tombari, A. Banti, and N. Minnaja
Extra Virgin olive oils
(7 samples) originating from different areas of Tuscany, defective olive oils
(5 samples), commercial edible seed oils (4 samples) and two commercial samples
of olive oil (one declared ‘extra virgin olive oil’ and one ‘olive
oil’) were studied by different calorimetric techniques: high sensitivity
isothermal, differential scanning, and modulated scanning calorimetry. The
temperature interval (–60) – (+30)C was explored for monitoring: i) the main features of the liquid↔solid phase
transitions, ii) the nucleation and growth
rate of the polymorphous crystalline phases of the triacylglicerols, and iii) the melting process. This investigation was
planned for verifying the utility and effectiveness of calorimetry for screening
quality and origin of olive oil. To this end, the main calorimetric operation
modes have been applied, the experimental results reported and their utility
for developing an effective and reliable screening protocol discussed.