Effect of amylose content on estimated kinetic parameters for a starch viscosity model

Abstract

Amylose Amylopectin Nonlinear kinetic parameter estimation Pasting curve Mixer viscometry Labview Brookfield viscometer Nonisothermal Inverse problem Rheology Rapid visco analyzer (RVA) a b s t r a c tThe apparent viscosity profile of starches during gelatinization varies with different amylose content. This study focused on the influence of amylose content on the kinetic parameters of a starch viscosity model for corn starches. The five parameters were: gelatinization rate constant (k g ), gelatinization activation energy (E g ), relative increase in apparent viscosity during gelatinization (A a ), relative decrease in apparent viscosity during shearing (B), and viscous activation energy (E v ). The parameters were estimated at different amylose content using both ordinary least squares nonlinear regression and the sequential method. The mixer viscometry approach was used to measure apparent viscosity. The first part of this paper presents parameter estimation results for waxy corn starch. The model was validated by using the parameters to predict viscosity for the same starch in a different measuring system, i.e., the RVA. The second part of this paper presents the estimated parameters for corn starch blends at different amylose content. The following parameters were significantly affected by amylose content: k g and E g both decreased with amylose content by an power-law relationship. Activation energy of gelatinization ranged from 121 to 1169 kJ/mol. The other parameters A a , B, and E v were not significantly influenced by amylose content. In summary, the gelatinization parameters k g and E g dramatically decreased as amylose increased from 3% to 35% (waxy corn starch blends).

Heat-induced changes of corn, potato, and wheat starches

“…The presence of relatively short chains of amylose and amylopectin is characterized by the opacity of the starch suspensions and the foods containing them. The suspensions usually exhibit a viscosity peak that begins after swelling and increases in the process of starch grain starch, followed by a decrease in viscosity due to grain degradation and polymer stacking [23,24].…”

Phenotypic diversity of starch pasting properties in cassava for food industry

“…The physicochemical properties of starches determine their suitability for certain end uses, while the relationships among their molecular structure, functional properties, and viscosity profiles (pasting curves) are powerful tools for representing the functional properties of starch. Each starch produces a different viscosity profile, even under identical processing conditions (Sulaiman & Dolan, 2013).…”

Rheological Characterization of Gastric Juices from Bread with Different Amylose/Amylopectin Ratios

“…In some papers, authors proposed to increase the bolus viscosity with addition of different fibers, to reduce the glycemic response and to increase satiety [13][14][15]. In such context, carbohydrates, especially amylose and amylopectin, have been used to modify the rheological properties of in vitro solutions [16][17][18][19][20][21][22]. In this study, we want to evaluate the impact of the amylose/amylopectin ratio, denoted by Am/Ap, on the rheological properties of the in vivo gastric juices during digestion.…”