Reduced amylose effects on bread and white salted noodle quality

Amylose content in wheat endosperm is controlled by three Wx loci, and the proportion of amylose decreases with successive accumulation of Wx null alleles at the three loci. The proportion of amylose is believed to influence end-use quality of bread and Asian noodles. The objectives of this study were to determine influence of the allelic difference at Wx-B1 locus on bread quality, bread firmness, and white salted noodle texture in a spring wheat cross segregating for the Wx-B1 locus and in a set of advanced spring wheat breeding lines differing in allelic state at the Wx-B1 locus. In addition, we examined the relationship between amylose content and flour swelling properties on bread and noodle traits. Fifty-four recombinant inbred lines of hard white spring wheat plus parents were grown in replicated trials in two years, and 31 cultivars and breeding lines of hard spring wheat were grown in two locations. Bread and white salted noodles were processed from these trials. The presence of the Wx-B1 null allele reduced amylose content by 2.4% in a recombinant inbred population and 4.3% in a survey of advanced breeding lines and cultivars compared with the normal. The reduced amylose was accompanied by an average increase in flour swelling power (FSP) for the Wx-B1 null group of 0.8 g/g for the cross progeny and 2.3 g/g for the cultivar survey group. The Wx-B1 allelic difference did not affect flour protein in cross progeny where the allelic difference was not confounded with genetic background. Bread from the Wx-B1 null groups on average had increased loaf volume and was softer than the normal group for the cross progeny and cultivar survey group. The Wx-B1 allelic difference altered white salted noodle texture, most notably noodle springiness and cohesiveness where the Wx-B1 null groups was more springy and more cohesive than the normal groups for both sets of genetic materials. Flour protein was more highly related to loaf volume than were FSP or amylose. Both flour protein and FSP were positively related to noodle textural traits, but especially noodle springiness and cohesiveness.