The Preparation Properties And Application Of Resistant Starch

Resistant starch(RS)is defined as the sum of starch and its degradation products which can't be digested and absorbed by healthy individuals' small intestine.It can be fermented or partial fermentation in the large intestine and produce short-chain fatty acids.It plays an important role in preventing type? diabetes and intestinal diseases,accelerating lipid metabolism,promoting the absorption of vitamins and minerals,controlling weight aspect and so on.As a new functional food raw materials,the preparation and application of resistant starch have become a hotspot in research of food science in recent years.Type RS3 resistant starch is described renewable,easy to control,stable under the condition of high temperature,which is one of the most industrialized production and application prospect of resistant starch.This topic used common wheat starch as a raw material,after the extraction of wheat starch,and then through the microwave-repeated freezing and thawing to prepare the typeRS3wheat resistant starch.Its water retention capability,micro morphology,crystal structure and viscosity and a series of physical and chemical properties were determined and researched.And added it to wheat flour to make into dough to study the rheological properties of the resistant starch and flour blending system.Finally,mix wheat RS3 type of resistant starch up with flour to make into steamed bread to research the influence of the adding amount of flour powder quality characteristics on the resistant starch,and the effect of the sensory quality and the astral construct on steamed bread,though which we can make sure the appropriate amount of resistant starch in the steamed bread.The main research contents and conclusions are as follows:1.The microwave method combined with repeated freezing and melting for preparation of wheat resistant starch was studied.To optimize the parameters of the preparation of resistant starch by using microwave-repeated of freezing and thawing method with single factor experiment and orthogonal experiment design.The results are as follows:Wheat starch milk quality score of 25%,microwave power 700 w,microwave interact 2 min,repeated freezing and thawing times for 6 times,under the condition of wheat RS3 yield was 15.85%.2.Using the scanning electron microscope,X-ray diffraction,differential thermal scanners and rapid viscosity analyzer,the nature of the original starch and resistant starch were studied.The results as follows:The water holding capacity of wheat RS3 decreased than the original starch,scanning electron microscopy(SEM)the results showed that resistant starch granules were changed from the original starch of elliptic or ball into irregular shape,losing complete structure,appearing surface fold.Infrared spectrum(IR)analysis shows that formation process of RS3 belongs to a physical change because there was no new Chemical groups to generate.X-ray diffraction(XRD)measurement results show that the crystal structure of wheat RS3 changed into more stable type B+V from the type A of the original starch.The results of differential calorimeter scanner(DSC)showed that the resistant starch on the DSC atlas had only one peak,it is a level of about 115? when because of amylose crystals melting heat caused by the endothermic peak.Rapid viscosity analyzer(RVA)determination results showed that the thermal stability of wheat RS3 is better when at 95?for losing gelatinization characteristics.3.In the rheological test of resistant starch and flour blending system,take resistant starch as a substitute to study the influence of resistant starch under the condition of different replacement ratio on the rheological properties of the dough.Results show that with the increase of resistant starch samples replacement ratio,the apparent viscosity of the dough value increases,the energy storage modulus and loss modulus of the dough also increased significantly,the viscoelasticity of the dough changed significantly,the creep compliance of the dough and creep recovery rate all reduced.It said the hardness increased.4.According to different proportions add the prepared RS3 to the wheat flour to mix powder,with the increase of volume of addition of resistant starch the water absorption of flour dough increased significantly,the time of dough formation increased,the quality index of flour is on decline.With the increase of resistant starch content,the appearance of steamed bread and its texture all are into a downward trend.The TPA determination of steamed bread shows that as resistant starch is added to increase,the hardness and chewiness increased,but its elasticity and resilience decreased.In order to ensure the nutritive peculiarity and the sensory quality of steamed bread,so resistant starch in the flour used to make steamed bread adding amount should be advisably controlled at 6%?8%.