K Nn mK - Amecamex.org.mx
K Nn mK - Amecamex.org.mx
K Nn mK - Amecamex.org.mx
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Food Science and Biotechnology in Developing Countries<br />
Process viscosity study on heterogeneous foods<br />
L. Medina Torres 1 *, E. Brito de la Fuente 2 , J.A. Gallegos Infante 3<br />
1,2 Departamento de Alimentos y Biotecnología, Facultad de Química<br />
Universidad Nacional Autónoma de México., 04510 México, D.F.<br />
3 Instituo Tecnológico de Durango<br />
Departamento de Ingenieria Química y Bioquímica<br />
Felipe Pescador 1930 Ote., Durango, Dgo. 34080., México<br />
Tel./Fax (5)56-22-53-08. email: luismt@servidor.unam.<strong>mx</strong><br />
INTRODUCTION<br />
On the food industry there are an important group of food systems that it are<br />
constituid by a dispersant phase, in this phase there are a lot of relative soluble<br />
components and a disperse phase with particles with distinct physics properties.<br />
The rheological properties are of great importance in food fluids as mermelades,<br />
salad dressing, soups, sauces and creams [Baudi, 1996]. The knowledge of<br />
rheological properties are very important in the industrial optimization as<br />
pumping, mixing, cooling, drying and others. The usual viscometers are not good<br />
for this systems cause the heterogeneous nature of the dispersion. With the<br />
objective of a best determination of the fluid properties it has been used the<br />
rheometry with mixing principles for heterogeneous systems. [Brito et al., 1998].<br />
Rheological measurements.<br />
EXPERIMENTAL METHODOLOGY<br />
It were working three different simples of heterogeneous foods: Salad<br />
dressing, orange mermelada and peach yogurt, at 25°C. The rheological<br />
measurements were making in a rotational rheometer (Haake, CV20N, RV20)<br />
with temperature control. It was used a system with helicoidal geometry adapted<br />
to rheometer.<br />
On the Figure 1 is shown the system used. The Viscosity data were obtained<br />
following the method. [Brito et al., 1998].<br />
The process viscosity was determinated with the next algoritm:<br />
η<br />
e<br />
=<br />
<strong>mK</strong><br />
p<br />
( n)<br />
K<br />
p<br />
N<br />
n −1<br />
RESULTS AND DISCUSSION<br />
(1)