Study On The Resistance Transformation Of Starch In Wheat Flour And The Effects Of Functional Characteristics

In this present study,two different methods including heat-moisture treatment,pullulanase debranching-lipid complex and heat-moisture treatment combined treatment was introduced to increase the content of resistant starch in wheat flour.Based on the influences of the properties,and practical application on this basis,the biscuit products were prepared from resistant flours,and the texture and sensory characteristics were studied and analyzed,which laid a theoretical foundation for the further production and application of modified flour.Firstly,the process of increasing the RS content in wheat flour by heat-moisture treatment(HMT),and the influences of on the physical and chemical properties and digestion characteristics of different gluten flours.It was determined that the optimal process conditions for the HMT to increase the content of resistant starch in the flour were as follows:the moisture content of the flour was 30%,the temperature of HMT was 100?,and the treatment time was 8h.Under these conditions,the RS content in wheat flour could reach up to 23.09%.In addition,further research found that the HMT significantly increased the gelatinization temperature of the flour samples,and made the starch structure in it more orderly;the relative crystallinity and crystal structure of the flours showed that the HMT changed the crystal structure of the samples and crystallized The type changed from A to A+V,which proved the formation of endogenous starch-lipid complexes.In addition,in the field of scanning electron microscopy,the surface of starch particles becomes rougher after HMT,which caused the aggregation of denatured protein and starch particles.Compared with the native flour,the swelling power and solubility of modified flours were significantly reduced.Debranching-lipid complex and combined HMT also had important effects on the structure and in vitro digestibility of wheat flour.Debranching treatment destroyed the crystal structure of starch in flours and increased the contents of amylose in the system.Then fatty acid(stearic acid)and vegetable oil(soybean oil)were used to complex with starch in flour to form amylose-lipid complexes(RS₅).Studies had shown that HMT further enhanced the interaction between lipid/fatty acid and starch molecules and increased the contents of starch-lipid complexes.After combined treatment,the RS contents of the wheat flour samples modified by fatty acid and vegetable oil was increased to 28.22%and 26.81%,respectively.Through the above method to study the transformation of starch resistance in flour,the results showed that HMT had a significant effect on increasing the RS contents in flours,and the process was simple and there was no contamination of external additives.The pullulanase debranching-lipid complex and HMT combined treatment methods were used to transform the resistance of starch.The starch-lipid complex(RS₅)with the highest RS content and the main anti-digestive effect was a new type of starch,which has a broader research prospect.The biscuit products were prepared by adding different proportions of different resistant flours to low-gluten flour.The biscuits were studied in terms of moisture and ash content,sensory evaluation,biscuit texture property analysis,and resistant starch content.Studies have found that when the amount of resitant flour added was 20%,the crisp taste of the biscuits is maintained and the sensory evaluation is better.In addition,the RS content of the biscuit sample with the resistan flour is much higher than that of the biscuit prepared with native flour.In the case of comprehensive consideration of sensory evaluation and resistant starch content,the biscuit products prepared by the two kinds of resistant flour combined with debranching-lipid complex treatment and the addition amount of 20%met the requirements of application research.