PHYSICAL-PROPERTIES AND GELATION BEHAVIOR OF A LOW-AMYLOPECTIN MAIZE STARCH AND OTHER HIGH-AMYLOSE MAIZE STARCHES

This paper examines the effect of changes in fine structure due to hyb rid breeding on gel formation and gel properties of high-amylose maize starches. Both small-strain oscillatory testing and uniaxial-compress ion testing ranked G' and texture/strength, respectively, in the same order of HYLON(R) V starch <HYLON(R) VII starch <low-amylopectin starc h (LAPS). The starch gels became more rigid and stronger as amylose co ntent of the hybrids increased from HYLON V starch to LAPS. It was als o noted in these studies that LAPS had the quickest onset of gelation and HYLON V starch had the slowest. The effect of preparation temperat ure on gel properties was also studied by cooking high-amylose starche s at 250 degrees, 270 degrees, 290 degrees, 310 degrees, 330 degrees F in a mini-jet cooker with minimal steam Temperature of jet cooking ha d an impact on the rate of sol-to-gel transformation of the starches, which in turn influenced the final gel properties. All three hybrids w ere strongest (highest fracture stress and strain values) when prepare d at 270 degrees F. HYLON V had the narrowest cooking tolerance formin g self-supporting gels from 270 degrees to 310 degrees F, while LAPS w as the most robust, forming acceptable gels throughout the range of te mperatures tested. (C) 1998 Academic Press Limited.