Submitted to: Carbohydrate Polymers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 15, 2010
Publication Date: June 15, 2010
Citation: Fanta, G.F., Kenar, J.A., Byars, J.A., Felker, F.C., Shogren, R.L. 2010. Properties of Aqueous Dispersions of Amylose-Sodium Palmitate Complexes Prepared by Jet Cooking. Carbohydrate Polymers. 81(3):645-651. Interpretive Summary: Amylose is a type of starch molecule that can form a molecular combination, or complex, with a fatty acid molecule. While this has been known for a long time, the development of new biobased products based on this chemistry requires an efficient, green technology for manufacturing such complexes on a large scale. In this study, high amylose corn starch was dispersed by excess steam jet cooking and combined with sodium palmitate to form amylose inclusion complexes which were treated with either acid or salt to alter the flow properties of the dispersions. The chemical and rheological properties of the resulting dispersions or gels were characterized and described. This information will be used by researchers and manufacturers to prepare biobased products such as water-based lubricants, lotions, and food ingredients (when the complexes are used as a dispersant for lipids) as well as potential replacements for more expensive natural gums.
Technical Abstract: Aqueous dispersions of high amylose corn starch were steam jet cooked and blended with aqueous solutions of sodium palmitate to form amylose inclusion complexes for investigation of their bulk properties. The rheological properties of the cooled dispersions depended on the starch concentration and varied from low-viscosity liquids (at 3.75 % and 5.00 % solids) to gels (at 6.64 % solids). Gel formation was not caused by the formation of permanent cross-links. Viscosities of the dispersions increase when they were acidified with 0.02 N HCl, and at pH 3.6, about 90 % of the dispersed solid precipitated from the aqueous dispersion, due to conversion of complexed sodium palmitate into insoluble palmitic acid. Addition of sodium chloride solution also increased the viscosities of jet cooked dispersions, and caused the amylose complexes to precipitate. The gelling properties of these preparations suggest practical applications as dispersants for lipids in foods, lotions, and water-based lubricants.