Study on physicochemical characteristics of waxy and high-amylose wheat starches in comparison with normal wheat starch

Abstract

Waxy and high-amylose wheats are genetically modified cultivars produced firstly in Japan. The physicochemical properties of waxy and high-amylose wheat starches were investigated and compared to those of normal bread-wheat starch. The waxy wheat starch (~ 1 % of amylose) showed higher gelatinization temperature, transition enthalpy and crystallinity of granules than the normal and high-amylose wheat starches. The paste of waxy wheat starch had higher peak viscosity and swelling power, lower pasting temperature and final viscosity, which are favorable for producing Japanese white-salted noodles (Udon) of high-quality. In contrast, the high-amylose wheat starch had higher amylose content (37.5%), blue value and wavelength of maximal iodine absorption but lower gelatinization temperature and crystallinity than the normal wheat starch. The paste of high-amylose wheat starch had lower peak viscosity, breakdown and final viscosity than that of the normal wheat starch. These properties of the high-amylose wheat starch contributed to improve textural properties of noodles which were similar to durum wheat noodles. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.