Abstract

A chocolate milk was prepared with a regional chocolate from Oaxaca, Mexico, including several factors of study, to characterize its physicochemical, and rheological properties. This research was divided into two main parts, first and short: analysis of five commercial beverages and second and large: a study of the elaborated chocolate milks in fresh and stored through fifteen days at 3°C. To prepare the beverages the official Mexican norm1 was followed, milk including three levels of solids (10, 15 and 20 % w/w), and utilizing two chocolate Oaxaca presentations (bar and powder), applying two stirring velocities (low and high), in which two gums (carrageenan 0.018%, and alginic acid 3.5%) were incorporated. With respect to the physicochemical properties the prepared beverages exhibited a pH range of 6.0 – 7.0. Water activity between 0.940 and 0.960 was measured, showing small variations during storage time. Density as expected, was higher than water, with a range of 1040 to 1100 kg/m3, as a function of the solids content. Color parameters indicated a light brown color, proper of this type of items. Whereas flow determinations showed a pseudoplastic liquid with a flow behavior index lower than 1.0, in which a light viscosity increasing was observed as a function of storage time, although some of the samples exhibited a dilatant response.

Keywords

milk beverage, chocolate, physicochemical and flow properties of a flavoured /functional milk.