Physicochemical and rheological characterization of "dulce de leche"

Abstract

Physicochemical and rheological characterization of "dulce de leche", a milk-based sauce especially popular in South America, was carried out on different types of commercial products (traditional, confectionery, reduced calories or reduced fat). Proximal composition, solid content, water activity, pH and color (Minolta Co., Ramsey, NJ) were evaluated. A controlled stress rheometer (Haake RS600; ThermoGap, Karlsruhe, Germany) was used to performflow curves, dynamic oscillatory test in the linear viscoelastic range and creep-recovery experiments. Although in all samples, h decreased with increasing g ′, corresponding to shear-thinning behavior, clear differences were found in the rheological characteristics of different types of products. Experimental dynamic data were successfully modeled using the Baumgärtel-Schausberger-Winter equation to predict the mechanical relaxation spectrum. Satisfactory prediction of other mechanical properties was validated using creep experiments.