PROBIEN   20416
INSTITUTO DE INVESTIGACION Y DESARROLLO EN INGENIERIA DE PROCESOS, BIOTECNOLOGIA Y ENERGIAS ALTERNATIVAS
Unidad Ejecutora - UE
artículos
Título:
Impact of calcium on viscoelastic properties of fortified apple tissue
Autor/es:
SALVATORI, D.; DOCTOROVICH, R.; ALZAMORA, S. M.
Revista:
JOURNAL OF FOOD PROCESS ENGINEERING
Editorial:
Wiley-Blackwell
Referencias:
Lugar: DOI: 10.1111/j.1745-4530.2009.00550.x; Año: 2009
ISSN:
0145-8876
Resumen:
The effect of calcium impregnation in 0.1 % and 0.53 % (w/w) Ca isotonic glucose aqueous solutions, at atmospheric pressure or under vacuum, on the viscoelastic behavior of apple slices using different tests (oscillatory shear and creep/recovery) was analyzed. All samples showed a viscoelastic solid behavior with the storage modulus (G’) dominating the viscoelastic response. Treated apple samples with or without calcium showed a pronounced decrease in G’ as compared with fresh tissue. Instantaneous compliance (J0), decay compliances (J1 and J2) and fluidity significantly increased after treatments while retardation times were approximately constant. Rheological parameters values depended on the impregnation conditions (pressure, calcium concentration in the solution, process time). Microscopic observations showed that impregnation at high calcium concentrations provoked severe folding of walls and/or a general inner disruption of cells with plasmolysis and membrane breakage in a different way according to the pressure applied (VI or AI processes ) and the treatment time, explaining the viscoelastic behavior.