Physical properties of yellow alkaline noodles from near-isogenic wheat lines with different Wx protein deficiency

This paper reports the results of a study of the relationship among the amylose content of flours and the physical properties, such as the texture, of yellow alkaline noodles (YAN) prepared from these flours. For this purpose, we used eight types of near-isogenic flours with different Wx protein deficiency under the Chinese Spring genetic background. With the use of the near-isogenic lines, it was possible to achieve similar flour characteristics, with the exception of the amylose content of starch in YAN, and to analyze clearly the effects of the amylose content on the physical properties of YAN. The results of this study indicated that the breaking force and breaking force/breaking deformation of YAN made from the eight lines basically decreased and that the elastic index, on the contrary, increased, when the amylose content of starch from the flours was reduced. The breaking force and elastic index of gels from the flours and starches of the eight lines showed similar tendencies to those described above with regard to YAN. These results showed that the physical properties of YAN are greatly influenced by the amylose content of the flour and the properties of the starch gel. A sensory evaluation of YAN indicated that noodles from the flours of single-null types, which lack either the Wx-A1 or the Wx-B1 protein but particularly the former, had somewhat lower hardness and better elasticity and smoothness than those made from flour having all three Wx genes. The results basically corresponded to those of the physical properties of boiled YAN. These facts suggest that wheat with a somewhat lower amylose content, when compared to wild-type wheat, is suitable for producing YAN with acceptable texture, especially when considering the elasticity and smoothness.