Characterization and emulsification properties of amylose inclusion complexes prepared from corn starch and plant oil derived fatty acid sodium salt mixtures

Starch is often chemically modified to improve its emulsification properties for food processing applications. Amylose inclusion complexes prepared using single pure fatty acid salts have been shown to be effective emulsifiers but these salts could be prohibitively expensive for industrial production. Therefore, amylose inclusion complex were prepared by steam jet cooking using more economical fatty acid salt mixtures of differing compositions derived from different plant oils. Complexes were obtained in 92-96 % yield and had good surface active properties regardless of the fatty acid salt composition. The complexes exhibited Type I 61V helical crystalline structures. Fourier transform infrared and nuclear magnetic resonance spectroscopy confirmed complex formation. Aqueous suspensions of the complexes had Newtonian behavior with viscosities and surface tensions between 0.0020 to 0.0028 Pa s and 43 and 49 mN m-1, respectively. Complexes emulsified corn oil at a 1:3 ratio of corn oil to complex suspensions, giving emulsion activity and stability indices between 180-213 m2 g- 1 and 33-41 min, respectively. These complexes prepared from an array of more economical fatty acid salt mixtures performed comparably to more costly complexes prepared from pure individual fatty acid salts. These starch-based emulsifiers are produced using industrially available equipment making them desirable for food and nonfood applications.