Comparatively Study The Quality And Nutritional Characteristics Of Steamed Bread Made By Yeast Fermentation And Laomian Fermentation

This paper is intended to compare the differences of the two fermentation between yeast and laomian fermentation on dough,gluten properties and digestion characteristics of steamed bread proofing before and after.The study used medium high protein flour and low protein flour as raw materials to make steamed bread by yeast fermentation and laomian fermentation respectively.Comparatively studied the effect of the two fermentation ways on dynamic rheological properties of the dough and gluten,on specific volume,aspect ratio and internal structure of the dough before and after fermentation and steamed bread.Then comparatively studied the effect of the two fermentation ways and the effect of steamed and baked modes on protein content,amino acid composition,amino acid score changes and in vitro digestibility.Follow in medium high gluten flour as the main raw material,commercially available grains powder(maize,black rice and rye powder)respectively by steaming,high temperature and high pressure and puffing process,in accordance with the powder grains and flour ratio is the ratio of 3:7,with ordinary steamed bread recipe to make steamed bread.Comparatively studied the effect of the two fermentation ways on dynamic rheological properties of the dough and gluten,on gluten content and gluten index and internal structure of the dough before and after fermentation.Comparatively studied the effect of the two fermentation ways on dough and steamed bread volume and ratio of height to diameter,on protein content of the dough after fermentation and the steamed bread,on amino acid score changes and the amino acid composition changes in steamed bread.Last,comparatively studied the difference of starch and protein digestion in the steamed bread between yeast and laomian fermentation.The results are as follows:The effect of yeast and laomian fermentation on dough characteristics,steamed bread quality and digestion characteristics during the production process of ordinary steamed bread.The results show that the effect of laomian fermentation on dynamic rheological properties of dough is larger,and so as the degradation of gluten;Compared to the yeast fermentation of dough,laomian fermentation can maintain the dough gluten network better,making pores uniform distribution;Laomian fermentation of dough can delay aging and improve sensory quality of steamed bread;The ordinary steamed bread made by laomian has higher protein and amino acids content,higher lysine score,and higher content of resistant starch and protein digestion rate than that of yeast fermentation;The bakened ordinary steamed bread made by yeast fermentation has the highest lysine score.However,the steamed ordinary steamed bread made by laomian fermentation has higher lysine score;The resistant starch content of steamed ordinary steamed bread is higher than that of bakened ordinary steamed bread made all by two kinds of raw material powder.The protein digestion rate of the steamed ordinary steamed bread is higher than that of bakened ordinary steamed bread,except of bakened steamed bread made by laomian fermentation and low gluten flour.The protein digestion rate of steamed bread made by high gluten flour as high as 91.12%,and by low gluten flour as high as 91.65%.The effect of yeast and laomian fermentation on dough characteristics,steamed bread quality and digestion characteristics during the production process of steamed bread added 15% sugar.The results show that the effect of laomian fermentation on dynamic rheological properties of dough is larger,and so as the degradation of gluten;Compared to the yeast fermentation of dough,laomian fermentation can maintain the dough gluten network better,making pores uniform distribution;Laomian fermentation of dough can delay aging and improve sensory quality of steamed bread added sugar;The steamed bread adding sugar made by laomian has higher protein and amino acids content,higher amino acid score and higher content of resistant starch and protein digestion rate than that of yeast fermentation.The protein digestion rate of steamed bread adding sugar made by medium high gluten flour as high as 94.34%,and by low gluten flour as high as 97.75%.The effect of yeast and laomian fermentation on dough characteristics,steamed bread quality and digestion characteristics during the production process of coarse cereal steamed bread.Corn,rice,and rye powder were taken to cook,high temperature and high pressure and puff respectively.The ratio of the processed coarsecereals and flour is 3:7.The results show that laomian fermentation can maintain the elasticity of the dough better,leading the dough deformation resistance enhancement;Laomian fermentation can improve the degradation degree of gluten,and decrease gluten index significantly;Compared with yeast fermentation,the surface of steamed bread billet is smooth,and starch granules and gluten protein combine more closely after laomian fermentation;The specific volume of the three different processing coarse steamed bread made by laomian fermentation are larger than that made by yeast fermentation;The resilience,cohesiveness and springiness of the three kinds of cereal steamed bread are significantly increased by the three treatments;Laomian fermentation can improve resilience and springiness and reduce hardness,gumminess and chewiness of the three kinds of cereal steamed bread;Laomian fermentation can increase the sensory score of the three kinds of cereal steamed bread;For corn steamed bread by laomian,high temperature and high pressure treatment leads the highest sensory score;For black rice and rye steamed bread by laomian,the sensory score is highest by raw powder,follow by high temperature and high pressure treatment.For the three cereal steamed bread made by the three kinds of cereals powder,the content of protein,total amino acid and essential amino acid of cereal steamed bread made by laomian is significantly higher than that by yeast fermentation.Puffing and cooking treatments can increase the content of amino acid of black rice and rye steamed bread;Protein digestibility and resistant starch content of cereal steamed bread by laomian are significantly higher than that of yeast fermentation;Protein digestibility of cereal steamed bread increases after high temperature and high pressure treating,however,protein digestibility decrease after puffing treatment.Cooking treatment can improve the content of resistant starch of cereal steamed bread,however,puffing treatment can decrease the content of resistant starch of cereal steamed bread.