Effects of citric acid on the viscoelasticity of cornstarch pastes.
The effects of citric acid on the rheological properties of cornstarch pastes were studied by steady shear and dynamic oscillatory viscoelasticity, intrinsic viscosity measurements and microscopic observation. The pH of cornstarch dispersion was adjusted between 6.0 and 3.0. The viscosity of the pastes was increased by lowering the pH (between 5.5 and 3.6), while the viscosity of samples with pH below 3.5 decreased further than that of the control (pH = 6.3). Citric acid promoted the collapse of starch granules; however, adding excessive citric acid led to the hydrolysis of glucose chains. No decrease in the viscoelasticity was observed for cornstarch pastes by adding acid at 25 degrees C after gelatinization.
Hirashima
Madoka
M
Department of Food and Human Health Sciences, Graduate School of Human Life Science, Osaka City University, Sumiyoshi, Osaka 558-8585, Japan.
Takahashi
Rheo
R
Nishinari
Katsuyoshi
K
D019343:Citric Acid / Q000494:pharmacology*; D004548:Elasticity; D005947:Glucose / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D013213:Starch / Q000737:chemistry*; D014783:Viscosity
D019343:Citric Acid; D013213:Starch; D005947:Glucose