The Modification And Application Of Resistant Starch From Tartary Buckwheat And Black Bean

Resistant starch refers to starch that cannot be digested in a healthy human small intestine.It has the effect of similar dietary fiber,strong anti-enzyme activity,high thermal stability,low insulin response,and can control post-prandial blood glucose balance,which is beneficial to diabetic patients.However,in most natural foods,the content of resistant starch is very small,and it is difficult to control the blood sugar balance.Therefore,it is important to increase the resistant starch content in natural foods.In this study,the resistant starch was prepared by physical and enzyme method using tartary buckwheat and black bean as raw materials,and its physical and chemical properties were studied.At the same time,the tartary buckwheat powder and black beans powder were applied to the noodle making to study their functional properties.The main results are as follows:1)The effects of pullulanase addition,autoclave time,autoclave temperature and pullulanase hydrolysis time on the yield of resistant starch were studied by single factor and response surface experiments.The optimal conditions were determined:under the modified conditions of the pullulanase addition amount of 6.29 npun/g dry starch,the autoclave temperature of 101.16 ?,the autoclave time of 30 min,and the enzymatic hydrolysis time of 8.08 h,The yield of starch was 19.36%;the amount of pullulan was 4.10 npun/g dry starch,the tempering temperature was 90.37 ?,the autoclave time was 30 min,and the enzymatic hydrolysis time was 7.26 h.The resistant starch yield was 12.54%.2)The microscopic structure,anti-enzymatic properties and thermal stability of the tartary buckwheat resistant starch and black bean resistant starch by physical and enzyme methods were studied with the original tartary buckwheat powder and black beans powder as control.The results show that the tartary buckwheat and black beans have stronger anti-enzymatic properties and higher thermal stability.Scanning electron microscopy analysis showed that the surface of the tartary buckwheat powder and black bean powder had a dense and crystalline structure,and the apparent morphology was significantly different from that of the original tartary buckwheat powder and black bean powder.X-ray diffraction analysis showed that the modified tartary buckwheat starch and black bean starch crystal structure changed from the unstable type A to the more resistant type B and V;The differential scanning calorimeter analysis found that the tartary buckwheat powder and black bean powder gelatinization peaks became wider.The initial temperature,the termination temperature,the gelatinization temperature range and the gelatinization of the phase change are all improved to some extent,indicating that the thermal stability is improved and the ability to resist enzymatic hydrolysis becomes stronger.3)Using tartary buckwheat and black bean powder to make noodles A(original tartary buckwheat,black bean powder 30 g each),and noodles B(original tartary buckwheat,black bean powder 20 g each,modified bitter powder,black bean powder 10 g each);Studying the quality characteristics of two kinds of noodles A and B,it is found that there is no significant difference between the two.The in vitro digestion characteristics of Noodle A and Noodle B were studied by in vitro digestion simulation method.In contrast,it was found that the reducing sugar digestion rate of noodle B was low and the reducing sugar digestion amount was small,indicating that resistant starch can reduce the digestion amount of starch and reduce the absorption of reducing sugar;Scanning electron microscopy was used to analyze the microscopic morphology of Noodle A and Noodle B.It was found that the starch granules of Noodle B were uniform and embedded in the dough,indicating that the addition of TGase made the protein network structure denser and further verified the in vitro digestion characteristics of Noodle B.