Dough rheological properties and noodle-making performance of non-waxy and waxy whole-wheat flour blends

Dough rheological properties and noodle-making performance of non-waxy whole-wheat flour (WWF) with partial- or full-waxy (PW- or FW-) WWF substitution were studied. The substitution levels were 0, 250, 500, 750, and 1000 g/kg, respectively. FW-WWF reduced the peak viscosity and pasting temperature of WWF blends as its substitution level was increased due to its higher proportions of B-type starch granules and short amylopectin chains, while PW-WWF increased peak viscosity with the increasing substitution level because of its higher amylopectin content. As demonstrated by farinograph and rheometer measurements, FW-WWF interfered with gluten development because of the increased competition for water by arabinoxylans and amylopectin; however, PW-WWF enhanced dough strength due primarily to its increased protein content. Consequently, FW-WWF showed a detrimental effect on cooked noodle texture as the cooked noodle hardness was reduced by 50% at the 1000 g/kg substitution level. In contrast, PW-WWF enhanced noodle integrity and elasticity by increasing cooked noodle cohesiveness and resilience by 10.1% and 14.8%, respectively, at the 1000 g/kg substitution level. The results suggest that with waxy WWF substitution, the changes in starch composition, arabinoxylans, and protein content could modify the interactions among flour components and influence the quality characteristics of noodle products.     

Effect of allelic variation at the Glu-3/Gli-1 loci on breadmaking quality parameters in hexaploid wheat (Triticum aestivum L.)

Low molecular weight glutenin subunits (LMW-GS) encoded by the Glu-3 loci are known to contribute to wheat breadmaking quality. However, the specific effect of individual Glu-3 alleles is not well understood due to their complex protein banding patterns in SDS-PAGE and tight linkage with gliadins at the Gli-1 locus. Using DNA markers and a backcross program, we developed a set of nine near isogenic lines (NILs) including different Glu-A3/Gli-A1 or Glu-B3/Gli-B1 alleles in the genetic background of the Argentine variety ProINTA Imperial. The nine NILs and the control were evaluated in three different field trials in Argentina. Significant genotype-by-environment interactions were detected for most quality parameters indicating that the effects of the Glu-3/Gli-1 alleles are modulated by environmental differences. None of the NILs showed differences in total flour protein content, but relative changes in the abundance of particular classes of proteins cannot be ruled out. On average, the Glu-A3f, Glu-B3b, Glu-B3g and Glu-B3i_Man alleles were associated with the highest values in gluten strength-related parameters, while Glu-A3e, Glu-B3a and Glu-B3i_Chu were consistently associated with weak gluten and low quality values. The value of different Glu-3/Gli-1 allele combinations to improve breadmaking quality is discussed.     

Relationship of Protein Quantity,Quality and Dough Properties with Chinese Steamed Bread Quality

Using selected Chinese and Australian wheats, flour protein content and composition of high-molecular-weight (HMW) glutenin subunits were studied in relation to northern style Chinese steamed bread quality. Flour protein content had a significant impact on Chinese steamed bread quality. The Chinese wheats were characterised by shorter Farinograph dough development time and stability in comparison with the Australian wheats. Dough stickiness in the Chinese wheat cultivars was a significant factor deteriorating Chinese steamed bread quality. A significant negative correlation was found between Farinograph stability time and steamed bread quality in Australian wheats while a significant and positive correlation existed in Chinese wheats. It would be necessary to increase the dough strength of Chinese wheat cultivars in order to improve their steamed bread making quality.     

小麦品种（系）间溶剂保持力差异及软质小麦资源筛选

为了筛选出具有应用价值的优良软质小麦种质资源,以55份高代小麦品系和2个软质小麦品种为试验材料,利用微量溶剂保持力（SRC）方法对其水SRC、碳酸钠SRC、乳酸SRC和蔗糖SRC进行了测定,并分析了4种SRC在品种（系）间的差异以及它们之间的相互关系。结果表明,不同小麦品种（系）间4种SRC差异均达到极显著水平。水SRC变幅为56.10%~77.15%,平均为65.32%;碳酸钠SRC变幅为68.57%~101.13%,平均为82.56%;乳酸SRC变幅为94.51%~138.86%,平均为114.03%;蔗糖SRC变幅为93.56%~121.88%,平均为109.03%。SRC的相关分析显示,4种SRC间均呈极显著正相关,其中水SRC与碳酸钠SRC的相关系数最大,为0.9834,水SRC、碳酸钠SRC与蔗糖SRC间的相关系数分别为0.8162和0.8409,而水SRC、碳酸钠SRC、蔗糖SRC与乳酸SRC间的相关系数相对较小,分别为0.6535、0.6410和0.6855。根据SRC值的测定结果,筛选出了6个4种SRC均低于软质小麦品种宁麦9号的种质资源,这些资源可作为低SRC小麦品种选育的中间材料加以利用。