INVESTIGADORES
ZARITZKY Noemi Elisabet
artículos
Título:
Correlation between transient rotational viscometry and a dynamic oscillatory tst for viscoelastic starch based systems
Autor/es:
NAVARRO A.; MARTINO M; ZARITZKY NOEMI.
Revista:
JOURNAL OF TEXTURE STUDIES
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 1997 vol. 28 p. 365 - 385
ISSN:
0022-4901
Resumen:
Gelatinized starch formulations including lipids and xanthan gum, typical of viscoelastic foodstuffs, were analyzed using a rotational viscometer (transient conditions) and an oscillatory rheometer. Ultra-rapid and slow freezing processing conditions, which can modify product stability, were also tested. Transient shear stress curves showed a typical overshoot and a structural breakdown; the Bird- Leider model satisfactorily fitted these curves. Model parameters were correlated with characteristic  peak stress (sigma max), peak time (tmax) and relative overshoot corresponding to the sigma vs time curve. Relationships between transient shear stress data and dynamic measurements (G', G*, delta) for viscoelastic ranges were found for the starch-based systems and were used to assign a physical meaning to Bird-Leider parameters. Viscoelastic starch systems were grouped in different zonesof the correlation diagrams based on structure properties like rigidity, stability to the applied strain and fluid characteristics after breakdown