Steamed Bread And Noodle Quality Evaluation Of Spring Wheat Varieties And Advanced Lines

The repeatable and accuracy evaluation procedures play an important role in wheat quality improvement. To establish an optimal quality evaluation system for northern style Chinese Steamed Bread (CSB) and dry white Chinese noodle (DWCN), and to investigate the relationship between wheat quality and the performance of steamed bread and noodle of wheat varieties and advanced lines from CIMMYT and China, four experiments were fulfilled. (1) Six flour samples differing in gluten strength and five water addition (WA) levels ranging from 70% to 90% of Farinograph Water Absorption (FWA) were used to understand the relationship between WA and steamed bread quality, in order to develop a matchable optimum WA for flours differing in gluten strength. (2) To select a better scoring system and to understand the association between subjective and objective parameters of steamed bread quality, 25 wheat genotypes were grown at four locations in 2002 in spring-sown wheat zones. Under the matchable WA levels, these genotypes were examined for their suitability to steamed bread made by a methodology of Huang et al (1993). The texture of northern style CSB was evaluated by a Texture Analyzer TA-XT2i and by trained panelists using the national standard method GB/T17320-1998. The color was measured by a Minolta CR-310 colormeter. (3) Using the fractionation and reconstitution procedures, eight genotypes from the same cross of Japanese cultivar 'Kanto 1077Chinese cultivar 'Baihuo' differing in the presence and absence of three Waxy proteins (Wx-A1, Wx-B1, and Wx-D1) were employed to determine the effect of Waxy protein deficiencies on amylose content, starch pasting properties and Chinese fresh noodle quality. (4) Twenty-nine wheat genotypes were sown in three environments, respectively. They were used to investigate grain hardness, flour protein content, wet gluten content, SDS sedimentation value, Farinograph parameters, Extensograph parameters, amylose content, RVA pasting properties, flour pentosan content , northern style steamed bread and dry noodle quality. The steamed bread and noodle quality were assessed subjectively by a trained panel and objectively by the texture analyzer TA-XT2L The objective is to compare the performance of CIMMYT and Chinese varieties and lines in steamed bread and dry noodle. The major results are presented as below.1. In the range of water absorption measured by the Farinograph, quality parameters of steamed bread made from different flours responded differently to various WA levels. WA was significantly and negatively correlated with steamed bread weight, loaf volume, width, height, specific volume and spread ratio. It also had a significant and negative influence on shininess, skin and crumb color, smoothness, structure, stress relaxation (SR) and total score of steamed bread made from weak flours (r =-0.66—-0.96). In the stated range, increasing WA significantly improves smoothness and structure of CSB made from strong flours (r =-0.88,0.77). The optimum water addition is 70%-75%, 80% and 85% of FWA for weak, medium and strong flours, respectively.2. Stress Relaxation (SR) had significant and positive correlation with total score of northern style CSB made from flours with different gluten strength, and determination coefficients were 0.94, 0.88 and 0.72, respectively. It is recommended as a major parameter in evaluating steamed bread quality. The BRl total score was significantly and positively correlated with total score from the national standard method (r=0.65). The BRl method can distinguish the small difference among steamed bread quality made from...