Location: Functional Foods Research Unit
Title: Effect of amylopectin on the rheological properties of aqueous dispersions of starch-sodium palmitate complexes Authors
Submitted to: Carbohydrate Polymers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 26, 2013
Publication Date: March 20, 2013
Citation: Byars, J.A., Fanta, G.F., Kenar, J.A. 2013. Effect of amylopectin on the rheological properties of aqueous dispersions of starch-sodium palmitate complexes. Carbohydrate Polymers. 95:171-176. Interpretive Summary: This research used steam jet cooking as a method to prepare a range of gel materials from corn starch. These materials can be used to replace more expensive gums or chemically-modified starches. This work showed how the gel properties depend on the type of starch, the amount of starch and the pH. These results will aid in the development of inexpensive replacements for gums in applications such as thickeners and dispersants for lipids in foods, lotions and water-based lubricants.
Technical Abstract: Aqueous dispersions of normal and high-amylose corn starch were steam jet cooked and blended with aqueous solutions of sodium palmitate to form amylose inclusion complexes. Partial conversion of complexed sodium palmitate to palmitic acid by addition of acetic acid led to the formation of gels. Blends of normal and high-amylose corn starch were used to vary the amylose fraction of the gels, and the linear viscoelastic moduli decreased with decreasing amylose fraction. Precipitation of the complexed starch at low pH showed that most of the amylopectin was not part of the gel network. The elastic modulus of the gels decreased sharply between 70 – 85 °C, and the transition temperature increased strongly with decreasing amylose fraction.