Development Of Low GI Bread And Determination Of Glycemic Index Of Its Final Product

With the development of the economy and changes in dietary structure,long-term consumption of over-processed of food and staple has become an important factor affecting people's health.The incidence of chronic diseases,especially diabetes,is increasing.Studies find that dietary intervention is the basis for the control of diabetes,wherein low glycemic index(GI)starch-based foods are more suitable for diabetics since they cause less postprandial blood glucose response.Therefore,the study of starch raw materials rich in slow-digested starch and resistant starch has certain significance for the development of low-GI starchy foods.The research of this paper can be divided into three parts:1.Screening for slow-digesting starches suitable for low-GI food development.Potato starch,bean starch and cereal starch were selected,and the basic composition,particle morphology,and starch of corn starch,rice starch,wheat starch,potato starch,tapioca starch,pea starch and chickpea starch were compared.Particle size distribution,coagulation,swelling,rheology,gelatinization properties,amylose content,starch components,physical and chemical properties,in vitro digestibility and estimate GI value were investigated.The results showed that the particle size distribution of the pea starch and chickpea starch was concentrated and the size was uniform.The starch gelatinization characteristics measured by the fast viscometer and the retrogradation value of pea starch and chickpea starch were obtained and found out to be aging easily;amylose of pea starch and chickpea starch were high;corn starch contained the most fast digestion starch content,while potato starch had the most slow digestion starch content,and chickpea contained the highest resistant starch.The results of in vitro digestion showed that the growth rate of in vitro digestibility curve of chickpea starch was the slowest.The eGI values of seven starches were: chickpea starch(48.9)< wheat starch(57.7)<pea starch(59.9)<corn starch(67.3)< tapioca starch(70.2)< potato starch(70.2)< rice starch(76.3).The eGI of legume starch was significantly lower than that of other starches.The results of this study had certain guiding significance for the development of low GI starch products.Second,with chickpea starch and high-gluten flour as the main material,the bread of good structure and taste quality were developed.Single factor experiments were carried out with different ratios of 0,10%,20%,and 30% chickpea starch adding into bread flour.The starch properties of bread flour including the acidity,moisture,specific volume and texture of the bread were obtained.,To explore the effect of different ratio of chickpea starch on bread quality,characteristics,chromatic aberration and odor determination were carried out.The results showed that with the addition of starch,the bread held more water,but the excessive addition would inhibit the bread proofing.When the amount of chickpea starch added was 20%,the dough formed time was short,and would stable for a longer time,and the combination was most suitable;acidity of the different proportions of chickpea bread flour were in line with the standard;the brightness of the bread skin was increased detecting by electronic sensory evaluation;the flavor and taste were soft,refreshing,non-sticky and elastic.With the increase of starch addition,the response value of electronic nose T and P sensor was also increased.The addition of 30% chickpea starch to the taste of bread reduced the flavor of bread.The addition of 20% chickpea starch retained the flavor of bread.It was also blended with the scent of beans and was suitable for matching.Third,based on the addition of 20% chickpeas,the formula was optimized and carried out on human GI test.The proportion of bread dietary fiber was added,and the flour variety was adjusted.The human GI pre-test was carried out on a single person basis to obtain the final formula of chickpea starch bread: 300 g of durum wheat flour(20% chickpea starch,5% chiaseed,6% guar gum),butter 40 g,yeast 3 g,edible salt 2 g,egg 30 g,water 280 mL,maltitol 30 g.The human GI experiment showed that the GI value of chickpea starch bread was 45.9±3.5,which belonged to low GI food category.It can stabilize blood sugar after eating.Sensory evaluation results show that low GI bread had good palatability.