Studies On Technological Properties Of The Mixture Flour Of Buckwheat And Wheat

The physicochemical properties of various buckwheat flours and wheat flours(as control) were determined and the technological properties of the mixture flours made from buckwheat and wheat were studied systematically with the international standard methods. The experimental results were showed as followings:Compared with wheat flour, buckwheat flours have lower moisture, higher ash and crude fiber content. Different milling fractions have significant difference in content of crude protein, crude starch, rutin . Amylase-activity in buckwheat flour was much lower than that in wheat flour. Water-binding capacity and falling number of buckwheat flour were obviously higher than those of wheat flour. However, sedimentation value of buckwheat flour was lower. As compared with wheat flour, buckwheat flour was rich in Lys, Arg and Asp. The amounts of rutin and Lys in mixture were increasing continuous with the increase of buckwheat flour.The mixture dough has also acted as the wheat dough properties as buckwheat flour content was below 30%. However, as increased above 50%, the mixing dough has never showed the wheat dough properties. When analyzed by Brabender Farinograph, the result was very complicity and has no practice value.As the amount of buckwheat flour in the blends increased, extension properties of mixing dough was weak, dough tenacity strengthened, dough spreading capacity decreased, the balance between tenacity and extension poor. By adjusting kneading (dough-mixed) time and relaxation time, the mixing dough process properties would be improved.A comparison of pasting characteristics of buckwheat flour to those of wheat flour indicated that buckwheat flour has higher peak viscosity, hot viscosity stability, pasting temperature. finial viscosity, setback and lower viscosity breakdown. As buckwheat flour increasing, peak viscosity, holding strength, finial viscosity, setback and pasting temperature of mixing flour were increased and holding strength was declined. The change of peak time was not obvious.Buckwheat flour has effect on the quality of bread. The mixing flour has good baking properties at 10% and 20% buckwheat flour. Loaf volume, specific volume and hardness, setback speed of bread with 1 0%and 20% buckwheat flour were similar to bread from100% common flour. But the property of bread containing buckwheat flour was prior to those of strong wheat bread. With 30% buckwheat flour or more, the mixing flour baking properties were not good, the volume and specific volume of bread were significantly lower than those of strong flour bread. Hardness and setback speed of bread containing 30% buckwheat flour were much higher than those of strong bread during staling. Setback speed of the bread with 30% buckwheat flour was the fastest during 3-26h. As buckwheat flour content was above 30%, the mixing dough was very difficult to deal with during the bread-making process.