IQUIR   05412
INSTITUTO DE QUIMICA ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Temperature dependency of viscoelastic properties of low-fat soft cheese after frozen storage
Autor/es:
MEZA, BARBARA ERICA; DE PIANTE VICIN, DANIEL; VERDINI, ROXANA ANDREA; RUBIOLO, AMELIA CATALINA
Lugar:
Foz de Iguazu
Reunión:
Congreso; 16th World Congress of Food Science and Technology; 2012
Institución organizadora:
International Union of Food Science and Technology (IUFoST).
Resumen:
The objective of this work was to analyze temperature dependency of the viscoelastic properties of a low-fat soft cheese after frozen storage. Commercial cheese bars were frozen and stored at -25 C during 33 days. After that, cheeses were thawed and stored at 6 C during 48 days for further ripening (frozen cheeses). Cheeses stored at 6 C during 48 days were used as control samples (control cheeses). Frequency sweeps (0.01-10 Hz) in the linear viscoelastic region at several temperatures (10, 20, 30, 40, and 50 C) were carried out in triplicate. Elastic modulus (G´), viscous modulus (G"), complex modulus (G*), and complex viscosity (n*) were determined. Time-temperature superposition model (TTS) was applied in order to analyze G´ and G" values. Weak gel model for foods (G*=AF*f^z) was used to study values of G*. Temperature dependency of n* at 1 Hz was analyzed with an Arrhenius type equation. Statistical analysis was done using ANOVA. TTS was satisfactorily applied to overlap G´ and G" values at low temperatures (10 to 30 C). Activation energy of n* for frozen cheeses was lower than for control cheeses, suggesting lower resistant to break up of cheese microstructure. Weak gel model parameters, z (number of interactions) and AF (strength of interactions), decreased as temperature increased from 30 to 50 C in both frozen and control cheeses. Also, z values were lower in frozen cheeses than in control cheeses, suggesting that frozen cheeses presented lower number of interactions than control cheeses.