INVESTIGADORES
ANDRES Silvina Cecilia
congresos y reuniones científicas
Título:
Physicochemical and rheological characterization of "dulce de leche"
Autor/es:
RANALLI N; ANDRÉS S. C.; CALIFANO A. N.
Lugar:
New Orleans
Reunión:
Congreso; Institute of Food Technologists Annual Meeting (IFT 2011); 2011
Institución organizadora:
IFT
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.