CIDCA   05380
CENTRO DE INVESTIGACION Y DESARROLLO EN CRIOTECNOLOGIA DE ALIMENTOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
EFFECTS OF RICE VARIETY, LOCUST BEAN GUM AND REPEATED HEATING/COOLING CYCLES ON VISCOSITY PROFILES AND SYNERESIS OF RICE GELS
Autor/es:
CORREA MARÍA JIMENA; FERRERO, CRISTINA; PUPPO, MARÍA CECILIA; CBRITES, CARLA
Lugar:
Santiago de Chile
Reunión:
Conferencia; II CONFERENCIA LATINOAMERICANA DE CEREALES; 2011
Resumen:
Rheological behavior of rice based gels during heated/cooled cycles is of great importance for many food applications, depends of the starch composition (amylose:amylopectin ratio) and can be improved by hydrocolloids, such as locust bean gum. In the present study, five rice varieties with different amylose content (two Japonica: Ariete and Euro, two Indica: Gladio and Suriname and one Waxy) were used to produce gels with addition of locust bean gum (LBG) at different levels (0.5%, 1.0% and 2.0%). Two types of assays were performed using the rapid viscoanalyser (RVA-4): 1) Standard profile (SP) following the AACC 61-02 method; 2) A multiple heating- cooling profile (MHCP): SP was repeated three times. The parameters determined from SP were peak viscosity, trough, final viscosity, breakdown, setback from peak and setback from trough; from MHCP, peak viscosity and trough after each cycle were determined. The gels obtained from the RVA were freeze (17 hours), thawed and syneresis was measured. The results show that when SP was followed, the peak viscosity ranged between 1924-3328 cP, the order of increasing viscosity was: Ariete > Waxy>Euro>Gladio>Suriname. The addition of LBG led to higher peak, trough and final viscosity values. In the case of Ariete pastes, the setback from peak, a parameter related to starch retrogradation, decreased when LBG was added, although opposite effect was observed in Indica varieties (Gladio and Suriname). When MHCP was followed, two patterns were found: Euro and Waxy viscosities of second and third peak were lower than first peak, whereas Ariete, Gladio and Suriname showed higher peak viscosities after the first profile. When LBG was added, the same trend was found, but, higher viscosities values were obtained. After freezing and thawing Euro (prepared according to MHCP) and Waxy gels, did not release water. In the other cases, addition of increasing levels of LBG decreased progressively the released water. In conclusion, viscosity stability of rice gels during heated/cooled cycles depends of rice variety and LBG can be an effective agent for reduction of syneresis in rice based food products.