Rheology of Rice Starch-Sucrose Composites

Abstract

The effect of sucrose at different concentrations (0, 10, 20 and 30%) on rheological properties of rice starch pastes (5% w/w) was investigated in steady and dynamic shear. The steady shear properties of rice starch-sucrose composites were determined from rheological parameters for power law and Casson flow models. At 257C all the starch-sucrose composites exhibited a shear-thinning flow behavior (n=0.25-0.44). The presence of sucrose resulted in the decrease in consistency index (K), apparent viscosity (Z a,100 ) and yield stress (s oc ). Dynamic frequency sweeps at 257C indicated that starch-sucrose composites exhibited weak gel-like behavior with storage moduli (G 0 ) higher than loss moduli (G 00 ). G 0 and G 00 values decreased with the increase in sucrose concentration. The dynamic (Z*) and steady-shear (Z a ) viscosities at various sucrose concentrations did not follow the Cox-Merz superposition rule. G 0 values as a function of aging time (10 h) at 47C showed a pseudoplateau region at long aging times. In general, the values of G 0 and G 00 in rice starch-sucrose composites were reduced in the presence of sucrose and depended on sucrose concentration.

Effect of tapioca starch addition on rheological, thermal, and gelling properties of rice starch

“…RS alone, like other cereal starches, showed a plateau value of G 0 after a long aging period. A similar trend was reported for other starches, such as corn (Chang, Lim, & Yoo, 2004), rice (Yoo & Yoo, 2005) and sweet potato starch (Lee & Yoo, 2009). In contrast, TS alone showed almost the same G 0 values during aging, showing that TS dispersion at 5 g/100 g concentration produced gels too weak to give a stable G 0 detectable by the instrument.…”

Viscoelastic Properties of Soft Materials on a Basis of Starch Mixtures

“…Chang and others () analyzed rheological properties of the mixtures of corn starch pastes with different carbohydrates and found that their viscoelastic properties decreased in the presence of sugars. Similar conclusions were drawn by Yoo and Yoo () who tested the mixtures of rice starch with sucrose.…”

“…The analysis of the effect of changes in sugar type and concentration on viscoelastic properties of paste made from corn starch was based on the results of rheological studies by Chang (Chang and others ) and Yoo (Yoo and Yoo ) for rice starch pastes. The curves of storage G ′ and loss G ″ moduli obtained in the measurements within the angular frequency range from ω = 0.62 to 62 s −1 , it is frequency sweeps over the range of 0.1 to 10 Hz at constant 3% deformation, were described using the power‐law model (Ikeda and Nishinari ) in the following form: The values of parameters k ′, k ″ as well as n ′ and n ″ of this model for Chang's measurements are presented in Table and for Yoo's experiments in Table .…”

“…Many researchers carried out studies on the effect of sugars on rheological properties of pastes obtained from starch coming from different botanical sources, for example wheat starch (Wong and Lelievre ), potato starch (Mita ), and sago starch (Ahmad and Williams ). Nevertheless, special attention is this field is given to the studies on stabilization of corn starch pastes (Chang and others ) and rice starch pastes (Yoo and Yoo ).…”

Effect of Cryoprotectant Mixtures on Rheological Properties of Fresh and Frozen/Thawed Mashed Potatoes

“…In order to describe the variation in the rheological properties of F and F/T mashed potatoes under steady shear, the data obtained from increasing shear rate measurements were fitted to the well‐known power law () and Casson () models. The Casson model is a structure‐based model that has been used for a number of food dispersions (Rao 1999), including cooked rice flour (Chun and Yoo 2004), acorn flour (Yoo, Kim and Yoo 2005) and rice starch dispersions (Yoo and Yoo 2005). As the development of flow models containing yield stress was not the objective, no additional effort was made on models containing yield stresses (e.g., Hershel–Bulkley).…”