Physical Properties and Gelation Behavior of a Low-Amylopectin Maize Starch and Other High-Amylose Maize Starches

Abstract

This paper examines the effect of changes in fine structure due to hybrid breeding on gel formation and gel properties of high-amylose maize starches. Both small-strain oscillatory testing and uniaxial-compression testing ranked G′ and texture/strength, respectively, in the same order of HYLON® V starch <HYLON® VII starch <low-amylopectin starch (LAPS). The starch gels became more rigid and stronger as amylose content of the hybrids increased from HYLON V starch to LAPS. It was also noted in these studies that LAPS had the quickest onset of gelation and HYLON V starch had the slowest. The effect of preparation temperature on gel properties was also studied by cooking high-amylose starches at 250 °, 270 °, 290 °, 310 °, 330 °F in a mini-jet cooker with minimal steam. Temperature of jet cooking had an impact on the rate of sol-to-gel transformation of the starches, which in turn influenced the final gel properties. All three hybrids were strongest (highest fracture stress and strain values) when prepared at 270 °F. HYLON V had the narrowest cooking tolerance forming self-supporting gels from 270 ° to 310 °F, while LAPS was the most robust, forming acceptable gels throughout the range of temperatures tested.