15C-24 |
Use of response surface methodology on manufacture of lactic beverages added with fat mimetics (Litesse and Dairy-lo) |
K. SIVIERI and M. N. Oliveira. Dept. of Pharmaceutical & Biochemical Technology, São Paulo Univ., Av Prof Lineu Prestes, 580, São Paulo, SP, 05508-900, Brazil Use of response surface methodology on manufacture of lactic beverages added with fat mimetics K. SIVIERI, and M.N. Oliveira, Department of Pharmaceutical and Biochemical Technology, São Paulo University, Av Prof Lineu Prestes, 580. 05508-900, SP, Brazil. katiasiv@usp.br Low fat fermented lactic beverages are products made with skim yogurt, whey, pulp or fruit juice, flavors and preservatives. These products should have low fat contents (0.5 to 2.5%) without loosing certain properties such as hardness, viscosity, spreadability which determine the consistency of the product. Thus, the present trend is to use fat mimetics to overcome this problem. The objective of this paper was to find the best proportion of two fat mimetics (Litesse and Dairy-lo) as an alternative to replace fat in lactic beverages manufacture. The effect of two independent variables: Litesse (X1) and Dairy-lo (X2) (0.5, 1.5 and 2.5%) on rheological properties was studied through Response Surface Methodology (RSM). Rheological properties were obtained at 5°C and 25°C using a Brookfield rheometer with plate and cone geometry. The rotation varied from 10 to 250 rpm using a cone CP 40. The experimental data were described by Power Law model. The main characteristic of the relationship shear stress - shear rate was development of hysteresis curves. The rheograms showed that the samples behave as a non-Newtonian fluid, pseudoplastic, with presence of thixotropy. Determination coefficient for the models ranged from 0.990 to 0.999 showing adequate fit of flow curves. The interactions of X1 and X2 was not statistically significant (P<0.05). In rheological models, Litesse exhibited an effect more significant than Dairy-lo; experimental error was < 0.04. Our results demonstrated that RSM was an indispensable technique for the development of the products, and determined the amounts of fat mimetics to be used in low fat lactic beverages. The proportions of Litesse and Dairy-lo to be used in low fat lactic beverages manufacture, and their rheological properties have been established.
Session 15C, Dairy Foods
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