• Food Science and Biotechnology
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• v.17 no.4
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• pp.780-786
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• 2008

Effect of acetylated starches (acetylated rice starch and acetylated tapioca starch) on rheological properties of hot pepper-soybean paste (HPSP) at different mixing ratios of rice flour (RF) and acetylated starch (AS) (10/0, 9/1, 8/2, and 7/3) was evaluated in steady and dynamic shear. All HPSP samples at $25^{\circ}C$ exhibited shear-thinning (n=0.31-0.36) and thixotropic behavior with high yield stresses and their steady flow curves were well described by power law and Casson models. The presence of AS resulted in the decrease in consistency index (K), apparent viscosity (${\eta}_{a,100}$), and yield stress (${\sigma}_{oc}$), and their predominant decreases were noticed at higher ratio of RF to AS (7/3 ratio). Arrhenius temperature relationship represents variation with temperature in the range of $5-35^{\circ}C$ with the high determination coefficients ($R^2=0.97-0.99$). Dynamic moduli (G', G", and ${\eta}^*$) values of HPSP samples mixed with AS were lower than those of HPSP with no added AS within the experimental range of frequency (0.63-62.8 rad/sec). Steady and dynamic shear rheological properties of HPSP samples seem to be greatly influenced by the presence of acetylated starch.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1119-1121
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• 2008

The effects of storage time (0, 1, and 2 month) and temperature (5, 15, and $25^{\circ}C$) on the dynamic rheological properties of hot pepper-soybean paste (HPSP) mixed with acetylated starches (AS) were studied by small-deformation oscillatory measurements. Dynamic moduli (G', G", and $\eta^*$) values of HPSP-AS mixtures increased with an increase in storage time and also decreased with increasing storage temperature. However, dynamic moduli values of the control (no added AS) were independent on storage time and temperature. Tan $\delta$ values (ratio of G"/G') in all HPSP samples did not change much with an increase in storage time and temperature. After 2 months of storage, the dynamic moduli of the HPSP-AS mixture samples were much lower than those of the control, indicating that the addition of AS can inhibit the retrogradation that developed over a long period of storage. Structural and rheological properties of HPSP samples seem to be stabilized by the presence of AS.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.3
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• pp.474-483
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• 2015

The textural properties of breads containing midified starches such as pregelatinized waxy corn starch, acetylated potato starch and hydroxypropylated tapioca starch, were investigated to determine the optimum addition level of modified starches. Effects of modified starches on dough properties were investigated through a farinogram and amylogram based on the different additional levels of modified starches (3%, 6%, 9%, 12% and 15% of flour content). Moisture contents and firmness values were measured to investigate the degree of retrogradation at 0 h, 36 h and 72 h after production. The levels of moisture contents were highest upon addition of pregelatinized waxy corn starch followed by acetylated potato starch and lowest upon addition of hydroxypropylated tapioca starch. Overall, higher moisture contents resulted in lower firmness levels. The preference scores by type of modified starch were highest upon addition of 9% hydroxypropylated tapioca starch, 3% pregelatinized waxy corn starch, and 6% acetylated potato starch, respectively. Preference scores were significantly correlated with textural properties such as volume, absorption, stability and weakness (p<0.01).