Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Entire DC Network

Polymorphism And Growth Behavior Of Low-Trans Fatty Acids Blends Formulated With And Without Emulsifiers, Marina Cerdeira, Silvana Martini, Roberto J. Candal, Maria L. Herrera Jun 2006

Polymorphism And Growth Behavior Of Low-Trans Fatty Acids Blends Formulated With And Without Emulsifiers, Marina Cerdeira, Silvana Martini, Roberto J. Candal, Maria L. Herrera

Nutrition, Dietetics, and Food Sciences Faculty Publications

Polymorphism and growth behavior of blends of a high-melting fraction of milk fat (HMF) and sunflower oil (SFO) formulated with and without the addition of sucrose esters (SE) P-170, P-1670, and S-170 were studied by pulsed 1H NMR spectroscopy, X-ray diffraction, and polarized light microscopy. The effect of SE on the solid content maximum (S max) or crystallization rate was observed only at low supercooling (values of ΔT below 15°C). The Avrami k n decreased as n values increased, indicating that SE inhibited growth and impeded nucleation. Addition of SFO modified the polymorphic behavior of milk fat, most likely owing …


A Probabilistic Approach To Model The Nonisothermal Nucleation Of Triacylglycerol Melts, Alejandro G. Marangoni, Thomas C. Aurand, Silvana Martini, Michel Ollivon Apr 2006

A Probabilistic Approach To Model The Nonisothermal Nucleation Of Triacylglycerol Melts, Alejandro G. Marangoni, Thomas C. Aurand, Silvana Martini, Michel Ollivon

Nutrition, Dietetics, and Food Sciences Faculty Publications

Crystallization studies are usually performed under isothermal conditions. Kinetic parameters characterizing the isothermal nucleation and growth processes can be obtained using classical nucleation and growth models. However, crystallization regimes found in nature, as well as those used in food and pharmaceutical processing, are rarely isothermal. Focusing on the nucleation stage, the approach followed in this work was to define a new parameter to characterize the driving force of nucleation, the supercooling-time exposure (β), which not only depends on the difference between the melting temperature (Tm) and the onset temperature of nucleation (Tc) ΔTc but also on the induction time of …


The Water Vapor Permeability Of Polycrystalline Fat Barrier Films, Silvana Martini, D. A. Kim, M. Ollivon, A. G. Marangoni Mar 2006

The Water Vapor Permeability Of Polycrystalline Fat Barrier Films, Silvana Martini, D. A. Kim, M. Ollivon, A. G. Marangoni

Nutrition, Dietetics, and Food Sciences Faculty Publications

The water vapor permeability of fat barrier films has been associated with structural characteristics such as polymorphism, crystal size, and chemical composition, among others. However, no mechanistic models have been proposed to describe this relationship. In this study, we have determined the effects of processing conditions on the structure and physicochemical characteristics of four fats and their relationship to water vapor permeability. Results suggest that the solids' volume fraction and the domain size of the fat crystals seem to be the most important factors controlling water vapor migration. Moreover, materials with relatively large crystalline domains will yield malleable films with …