CIDCA   05380
CENTRO DE INVESTIGACION Y DESARROLLO EN CRIOTECNOLOGIA DE ALIMENTOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Physicochemical and rheological characterization of ?dulce de leche?.
Autor/es:
N. RANALLI; S. C. ANDRÉS; A. CALIFANO
Lugar:
New Orleans
Reunión:
Congreso; 2011 IFT Annual Meeting; 2011
Institución organizadora:
Institute of Food Technologist
Resumen:
?Dulce de leche? (DL) is a milk-based sauce popular in South American countries. Primarily consumed as a jam, it tastes vaguely similar to caramel. It is prepared by boiling whole milk with added sucrose until 70% total solids is reached. Rheological characterization is required for product standardization, process development, quality control, and consumer acceptability. The objectives of this work were: i) to analyze the physicochemical properties of commercial DL, ii) to rheologically characterize these products, iii) to model rheological data within the linear viscoelastic range by estimating the relaxation mechanical spectra of the systems, iv) to validate the models by comparing experimental creep-recovery results with the predictions calculated from the mechanical spectra.  Physicochemical and rheological characterization of DL was carried out on different types of commercial products (traditional, confectionary, reduced calories, and reduced fat). Proximal composition, solid content (76-59ºBrix), water activity (0.764-0.882), pH, and color (Minolta CR-400 colorimeter) were evaluated. A controlled stress rheometer Haake RS600 was used to perform the rheological experiments using a serrated plate-plate sensor (35mm diameter, 20ºC).  All steady-state flow curves showed a shear-thinning behavior and were modeled using Cross? equation. Dynamic oscillatory tests showed that storage moduli (G´) were higher than loss moduli (G´´) for nearly three decades, and a ?plateau? region at intermediate frequencies was observed for all the assayed brands except for a ?light? product. Viscoelastic behavior of DL was successfully modeled using Baumgaertel-Schausberger-Winter equation (IRIS Rheo-Hub software) to predict the mechanical relaxation spectrum. Creep compliance was predicted from this spectrum and compared with experimental data to confirm the correct fitting of the mechanical spectrum.                                               Modeling dynamic data to convert it into the time domain by the application of BSW equation is a useful tool, especially for establishing a rheological data bank and analyzing viscoelastic experiments of this type of product.