The Quality And Features Of Buckwheat Steamed Bread

Buckwheat contains a lot of medicines ingredients, has significant efficacy to prevente disease, and is a kind of high value of health food products. But the buckwheat contains less glutenin and gliadin, when useing buckwheat to make steamed bread, it will affect the quality of steamed bread. So this paper mainly study the effect of buckwheat on steamed bread quality and its functional properties, and selecte the formula of buckwheat steamed bread product which has a good quality and functional properties, and compare with the buckwheat steamed bread on sale in the market,then to study the change of microscopic structure.Adding 5%, 10%, 15%, 20%, 25%, 30% of the buckwheat flour into the dough, to study the dough and sensory quality of the steamed bread and functional characteristics. The results show that when adding 15% buckwheat flour, the mixed dough and steamed bread both have a better quality. When adding 15% buckwheat flour into the steamed bread, the content of polyphenols and flavonoids in the buckwheat steamed are 2.84 times and 3.00 times compared with the content of polyphenols and flavonoids in the steamed bread. But when the content of buckwheat flour is 15%, the amount of total amino acids, essential amino acids and non-essential amino acids in the buckwheat steamed bread are lower than pure wheat bread.Under the premise of senses quality assurance to compensate for lack of amino acid content in the buckwheat steamed bread, adding 1% isolated soy protein powder(Soy Protein Isolate, SPI) to make SPI buckwheat steamed bread, adding 2% isolated whey protein powder(Whey Protein Isolate, WPI) to make WPI buckwheat steamed bread, and comparing the pure wheat steamed bread, with buckwheat steamed bread, WPI buckwheat steamed breadand and SPI buckwheat steamed bread. The results show that the content of essential amino acids was WPI buckwheat steamed bread> SPI buckwheat steamed bread> pure wheat bread> Buckwheat steamed bread, and the amino acid score of SPI buckwheat steamed bread and WPI buckwheat steamed bread are higher than pure wheat steamed bread. Buckwheat steamed bread can reduce postprandial blood glucose values of rats at 30 min, and the value of glycemic index(GI) is less than pure wheat steamed bread, and after adding SPI or WPI into the buckwheat steamed bread does not affect the hypoglycemic effect. The protein digestibility of buckwheat steamed bread is significantly lower than that of pure wheat steamed bread, adding SPI or WPI into the buckwheat steamed bread, the protein digestibility improved, while the antioxidant activity of WPI buckwheat steamed bread is the highest. Comprehensive analysis, WPI buckwheat steamed bread has better quality and features.Comparing with the three buckwheat steamed breads on seal and different formulations of the buckwheat steamed breads can known, number 1 of the buckwheat steamed breads on seal has the same amino acid content with the WPI buckwheat steamed bread, but the sensory quality, hypoglycemic and antioxidant effect is far less than the three different formulations buckwheat steamed bread. Not only the amino acid content of number 2 of the buckwheat steamed breads on seal low and sensory quality is poor, hypoglycemic and antioxidant effect are also not obvious. Although the antioxidant effect of the number 3 is same with WPI buckwheat steamed bread, but its amino acid content is extremely low, sensory quality is poor, and hypoglycemic effect is weak. Therefore, compared to the buckwheat steamed breads on seal, homemade WPI buckwheat steamed bread both have better sensory quality and features.Using low field nuclear magnetic resonance(NMR), Fourier transform infrared spectroscopy and X-ray diffraction(XRD) to study the change of microscopic structure of wheat steamed bread dough and buckwheat steamed bread dough, WPI buckwheat steamed bread dough. The result shows that in the buckwheat steamed bread dough the proportion of water which the relaxation time is on T22 period is increased, the content of β-pleated sheet is increased, the content of β-turn and α-helix is reduced, at the same time, the crystallinity of starch is increased. WPI buckwheat steamed bread dough is close to wheat steamed bread dough about the above indexes.