Rheological Behavior of Low-Fat Dulce De Leche with Added Xanthan Gum

Abstract

Dulce de leche (DL), a typical jam of South America, is commercialized with diverse flow characteristics that corresponds to its different uses. In order to predict the adequate composition to obtain target rheological properties, low-fat dulce de leche (LF-DL) samples with different water (23.7–60.3%) and xanthan gum (0.173–0.555%) contents were prepared using skim milk (0% fat), sucrose (172.7 g/L) and glucose (28.98 g/L) following the traditional method, and their flow behavior was measured. Steady-state flow curves were modeled and the obtained Herschel-Bulkley's parameters were regressed as a function of water and xanthan gum contents; from this set of equations, an adequate composition to produce LF-DL with flow behavior similar to a premium commercial brand was predicted. The procedure was experimentally validated. A mathematical useful tool for the industry to calculate a suitable formulation to obtain a given type of LF-DL is presented. Practical Applications Dulce de leche (DL) is a complex biopolymeric matrix, with milk proteins, sugar and more than 6% of fat. This paper studies the effect of moisture and xanthan gum (as fat replacer) in the rheological properties of a low-fat dulce de leche (LF-DL). It provides a tool for understanding the flow behavior of LF-DL and to determine the required composition of this system needed to achieve a selected rheological behavior. In order to obtain a mathematical model to predict the compositon that would present the desired viscosity for each product application, the formulation of LF-DL with xanthan gum as fat replacer was related with viscosity of the product. Employing the proposed methodology, it was possible to select the combination of components to obtain LF-DL with similar rheological characteristics to a traditional commercial brand well accepted by consumers.