Rheological properties of heated cross-linked waxy maize starch dispersions

• Autor(a) principal: Silva, Pedro M. S. da
• Data de Publicação: 1998
• Outros Autores: Oliveira, J.C., Rao, M.A.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.14/5942

The effect of starch concentration on time-dependent, steady shear, and dynamic shear rheological properties of heated cross-linked waxy maize starch (CWM) starch dispersions was studied. The influence of storage time at 5°C on the rheological properties, the applicability of the Cox-Merz rule, and the sol-gel transition of a 5% (w/w) were also examined. The heated CWM starch dispersions exhibited antithixotropic and shear-thinning with yield stress behaviors. The former behavior increased with both starch concentration and shear rate between 100s-1 and 400s-1. As expected, the apparent viscosity at a fixed shear rate and the yield stress increased with starch concentration. Because the Cox-Merz rule was not applicable, the dispersions may be classified as weak gels. Both differential scanning calorimetry and thermo-rheological data showed that the onset of starch gelatinization temperature was 63°C.