Study On The Preparation,Physical And Chemical Properties And Application Of Buckwheat Resistant Starch

As a kind of medicinal and edible crops,buckwheat has been accepted by people.At present,there are many studies on the functional components of buckwheat such as flavonoids,D-CI,active protein peptides,while less on the resistant starch.In this paper,buckwheat were used as material to study the physicochemical properties of buckwheat starch.Three different kinds of methods were used to prepare resistant starch,the best method was used to preparation resistant starch.On the basis of single factor experiment,the response surface methodology was adopted to optimize the process parameters to determine the best extraction process.On this basis,the physical and chemical properties of potato resistant starch were tested,and add it to the coated powder fried food to research how it influence the quality.The main results were as follows:(1)By comparing the physicochemical properties with corn starch,potato starch,sweet potato starch,pea starch,buckwheat starch,the buckwheat starch showed poor thetransparency and freeze-thaw stability,while the gel ability was strong and the thermal stability was good.(2)Taking the resistant starch content as the index,hot press,enzymatic hydrolysis and hot press-enzymatic hydrolysis were used to prepare resistant starch,which one is more helpful to improve the resistant starch content was analysed.The result showed that hot press-enzymatic hydrolysis was helpful to improve the resistant starch content,so the hot press-enzymatic hydrolysis was used to prepare resistant starch.On the basis of single factor experiment,the response surface methodology was adopted to study the reaction conditions for buckwheat resistant starch content.The optimal reaction conditions obtained were thermal-press temperature 121.04 ?,pullulanase debranching time 16.0h,pullulanase amount 8.72U/g,cold preservation time 24.61 h,the prediction of resistant starch content was 30.44%.Based on the optimal process,RS content experimentally obtained was 29.58%,in agreement with the predicted values.(3)Taking the common pulverization as reference,the influence of superfine pulverization on resistance starch content was studied.The result shows that: superfine pulverization was helpful to improve the resistant starch content,it could make the resistant starch content increased by about 6%.(4)Taking the buckwheat starch as reference,the light transmittance,swelling degree,solubility,water holding capacity,water absorption rate,particle morphology and thermal properties of resistant starch were studied.The result shows that: RS3 showed relatively poor transparency and solubility and high Swelling degree,water absorption and water holding capacity.The structure of buckwheat starch transformed from complete granular structure to irregular and lamellar structure.The crystal structure of buckwheat starch changed from A type crystal structure to B type crystal structure.RS3 showed relatively high thermal stability.(5)Adding resistant starch to the coated powder fried food and studying how it influences the textural properties,color,oil content and water content of fried products.The result shows that: the suitable adding amount of resistant starch can improve the moisture,brittleness,color and quality of fried products and reduce oil content of fried products.