Structure Of High Amylose-calcium Complexes And Their Resistance To Enzymatic Hydrolysis

Our country is the "severe disaster area" of diabetes,the number of patients has reached116 million,ranking first in the world.For such a large group of patients,comprehensive treatment needs to be combined with drugs,diet,exercise and other aspects.In order to balance the dietary habits of people with starchy food,one method is to convert starch into resistant starch,and add it as auxiliary material to starchy food,so as to reduce the GI value of food.At present,there are many kinds of food containing resistant starch in the market,but there is no food rich in resistant starch that can be rehydrated and prepared with water.This paper used two different calcium chloride solutions to deconstruct high amylose starch particle and prepared high amylose starch-calcium(HAS-Ca)complex.It was found that the complex had good rehydration and anti-enzymatic hydrolysis property.The main research work of this paper is as follows:In this paper,the structure and enzymatic hydrolysis property of HAS-Ca complex were firstly discussed,and the structure model of the complex was established.When the HAS-Ca complex was reorganized,amylose and amylopectin molecules were affected by the conformation and intermolecular force.They would aggregate respectively to form amylopectin rich region(mostly rapidly digestible starch),amylose rich region(most of them were resistant starch),and the mixed area of amylose and amylopectin(slowly digestible starch and resistant starch).Ca²⁺is easy to coordinate with amylopectin,mainly distributed in the area of rapidly digestible starch,which can be released after enzymatic hydrolysis.OH^-in Ca Cl₂ solution will make the complex structure loose,which promote the combination with Ca²⁺and improve the rehydration.The rehydration of HAS-Ca complex was basically 200%,up to 250±18%,significantly higher than the control sample.The content of resistant starch is more than 50%,and slowly digestible starch is 20%.The HAS-Ca complex has good rehydration and high resistant starch content at the same time.In order to improve the rehydration and resistant starch content of the complex,the effect of citric acid on the structure and properties of the complex was discussed.It was found that the Ca content in HAS-Ca complex increased and the content of resistant starch significantly increased with the addition of citric acid,up to 80%.But the rehydration decreased to 200%.It indicated that when the degree of acidolysis was too high,the Ca content in the complex decreased,the rehydration rate decreased to 100%,and the content of resistant starch decreased to 60%.According to the texture curve of acid-hydrolyzed HAS-Ca complex after rehydration,it has high hardness and no adhesion,showing gel texture,which is different from the texture of commercial rice paste after rehydration.Subsequently,the process was further improved in this paper,and the water precipitation process was used to replace the original alcohol precipitation process to further improve the rehydration and anti-enzymatic hydrolysis of HAS-Ca complex.It was found that the sample yield range of HAS-Ca complex prepared by water precipitation process was 90?100%,slightly lower than that of the sample prepared by alcohol precipitation process,but its rehydration was increased to 240.74±2.7%,with good rehydration performance.Secondly,according to the texture curve of HAS-Ca complex by after rehydration,the hardness value is moderate and has a certain adhesion force,which is close to the texture curve of commercial rice paste after rehydration.Then its in-vitro enzymatic properties were determined,in which the content of resistant starch was 80?85%,showing good anti-enzymatic hydrolysis property.In conclusion,HAS-Ca complex with good rehydration performance and anti-enzymatic hydrolysis was designed and prepared by analyzing the structure,determining in-vitro enzymatic hydrolysis property,characterizing the structural changes in different enzymatic hydrolysis stages,and improving the preparation process.On the one hand,this study breaks through the research limitations of high amylose starch and provides a theoretical basis for the preparation of rehydrated resistant starch by high amylose starch.On the other hand,it also provides new ideas for the design and development of high amylose in special functional foods.