Studies On Effects Of Quality Characters After Flour Blending By Different Wheat Varieties And Their Biochemical Basis

Nine wheat varieties, which have evident difference in genotype and quality character were selected for flour blending in pairs. There are thirty-six flour-blended combinations in total. Nine mixed flours were formed in the proportion of nine (0.1:0.9~0.9:0.1) in each combination. Zeleny sedimentation value, wet gluten content and dry gluten content of each flour-mixing were measured and their improvement rates were calculated and effect of flour blending were analyzed. Five protein composition contents of nine varieties were measured and analyzed relationship between each composition and quality effect of flour blending, between gliadin subunits and quality effect. The size and shape of starch granules and endosperm structure were observed by scanning electron microscope and studied the relationship between endosperm texture and quality effect of flour blending. The results indicated that:1. After flour blending in different wheat varieties, Zeleny sedimentation value, wet gluten content and dry gluten content of flour-mixed were higher or lower than two varieties of simple additive value (mean), improving or reducing quality traits (median improvement rate is positive or negative). In thirty-six flour-mixed combinations, fifteen combinations' improvement rates of Zeleny sedimentation value were positive and twenty-one were negative. Eighteen combinations' improvement rates of wet gluten content were positive and eighteen combinations' were negative. Sixteen combinations' improvement rates of wet gluten content were positive and twenty combinations' were negative. Twenty-one combinations' improvement rates of Zeleny sedimentation value, wet gluten content and dry gluten content increased or reduced synchronously, but fifteen combinations' improvement rates changed in different direction.2. In each combination of flour blending, the test value and theoretical value of Zeleny sedimentation value of flour-blended increased gradually with the proportion of high quality improving, showing certain regularity.3. Flour mixing between strong gluten varieties, Zeleny sedimentation value changed little, that is improvement rate was near zero, dry gluten content increased, that isimprovement rate was positive, wet gluten content decline that is improvement rate was negative. Flour blending between two medium gluten varieties, quality traits of flour-mixed tended to reduce. Quality traits of flour- mixed tended to improve during two weak gluten varieties for blending. Flour blending between strong gluten and medium gluten varieties, quality traits of flour- mixed tended to reduce. Flour blending between medium gluten and weak gluten varieties, quality traits of flour- mixed obviously improved.4. Flour blending during different genotypes of wheat varieties, the changes of Zeleny sedimentation value, wet gluten content and dry gluten content varied according to wheat varieties with different genotypes of wheat varieties. The genotypes of wheat varieties affected effect of flour blending to a large extent.5. Flour blending among different wheat variety, the changing range of flour-mixed' quality traits, that is effect of flour blending is the greatest in 0.3:0.7, 0.4:0.6,0.5:0.5.6. Selecting wheat varieties, which contain high insoluble protein and low albumin and glutenin for flour mixing could increase Zeleny sedimentation value. Selecting wheat varieties contained low albumin and high insoluble protein, gliadin and glutenin could increase gluten content.7. Subunit co -9, subunit oo -10 and subunit y-11 of gliadin could reduce Zeleny sedimentation value of flour-mixed. These 3 subunits can hold down improving of processing quality characters in flour-mixed.8. Flour blending during different wheat varieties, which had obvious diversity in endosperm texture was propitious to improving quality characters, and vice versa.