Study On The Structure And Food Functional Properties Of Rice Debranched Starch Precipitated By Different Alcohol Media

Amylose can self-assemble into helical structure in solution and is widely used in food,chemical,medicine and other fields.At present,it is very difficult to obtain high amylose material from gene breeding,but the best way is to prepare it by biological method.The rice yield in China has been high for 12 years in a row,but it still needs to be further explored to obtain rich economic benefits from rice cultivation through deep processing.In this paper,on the basis of complete gelatinization of indica and glutinous rice starch,amylopectin molecules were debranched by pullulanase to obtain amylopectin mixture with high degree of polymerization.At the same time,anhydrous ethanol(ABE,25%,50%),n-butanol(NBA,25%,50%),iso-amyl alcohol(ISA,25%,50%)were compared and studied.25%,50%)and debranched amylose,and the structure and food function of starch and alcohol complexes.The main results are as follows:1.The results of chain length distribution of indica rice starch and its alcohol complex showed that the content of B₁ chain was higher in 50%ABE solution,and the content of B₂chain was higher in 25%ABE solution.At 50%NBA concentration,the content of B₃and C chain in the complex increased significantly,while the content of short chain was higher at25%NBA concentration.Under the action of 25%ISA,the content of B₃ chain in the precipitation complex increased significantly.The results of chain length distribution of debranched glutinous rice starch and its alcohol complex showed that 50%ABE increased the content of amylopectin A and B₁,25%ABE increased amylopectin B₂.In 50%of the NBA,there was A significant increase in A-chains,while in 25%of the NBA,there was a significant increase in B₂chains.The B₁chain is significantly higher in 50%ISA than in 25%ISA.ABE significantly increased B₁ chain,NBA significantly affected A chain,ISA easily combined B₃ chain.The polarity of the solution system was changed with the increase of alcohol solution concentration,and the chain length distribution of alcohol-starch complex was significantly different.2.Structure characterization of indica rice starch debranched and its alcohol complex:XRD results showed that the alcohol-starch complex presented A polycrystalline mixture system,with A V-shaped crystal structure after 25%ABE extraction,and an A-shaped crystal structure after 50%ABE extraction.And 25%NBA concentration extract was V type,50%concentration was C type;The amyl alcohol solution at both concentrations is a C-type crystal.The crystallinity values of different ligand alcohols varied greatly.At 25%NBA,the highest crystallinity value was 39.47%.At 50%concentration,the crystallinity values of the three alcohols complexes were ISA>NBA>ABE.While at 25%concentration the preferred crystallinity was sorted as:NBA>ABE>ISA.The maximum absorption peak of amyloid-iodine complex extracted by 25%ISA was at 609nm,and the absorption value at the maximum absorption peak was 1.51.The absorption values at the maximum absorption peak of 25%NBA,50%ABE,50%NAB,25%ABE,and 50%ISA were 1.46,1.34,0.88,respectively.Compared with the original starch,To,TP and Tc of the complex of the three alcohols with the debranched rice starch were all deviated to the left.The initial temperature and peak temperature in 50%NBA solution were 103.58?and 103.9?,and the gelatinization temperature range was the shortest.The?H value of the starch in 25%ABE and 50%ABE solutions increased.3.The order degree values of the three alcohol solution complexes at 50%concentration of debranched glutinous rice starch and its alcohol-complex were as follows:ISA>ABE>NBA;At 25%concentration,the order is as follows:after complexing NBA>ABE>ISA with alcohol,new FT-IR peaks appear at 2880 cm^-1 and 1615 cm^-1,which correspond to the stretching vibration of C-H bond and C=O bond,respectively.C/V type mixed crystal structure was formed in 25%Abe solution,while A type crystal was formed in 50%Abe solution.In NBA and ISA solutions,B/V type crystals were obtained.The relative crystallinity of the complexes formed at 50%ABE is greater than that formed at 25%ABE.The ISI value of 50%ethanol-starch is the highest,and the ability to extract amylose and iodine complex is strong.The initial temperature,peak temperature and end temperature of the complex formed by the three alcohol solutions and debranched glutinous rice starch were all shifted to the right compared with the original starch,and its structure was unstable due to heat.4.The percentage of surface area of B-type starch grains in starch of indica rice and glutinous rice and their alcohol complexes increased significantly,and the surface area was larger.In the debranched indica rice starch,the alcohol complex formed by 50%ABE and25%ISA solution with amylose has good transparency,indicating that the complex has good dispersibility in water solution.The debranched glutinous rice starch and its alcohol complex have good solubility at high temperature,and the light transmittance of the complex with50%NBA is the best.The moisture analysis of the alcohol-debranched starch complex showed that the structure of the starch molecular network was weakened and the water molecules"detached"from the tight network structure to become free flowing water.The results showed that the type and concentration of alcohol affected the formation of amylose complex.The structural characteristics of the complex were studied by mixing different alcohol and concentration with the amylose produced by debranching.The results showed that different alcohol and concentration could be used for the extraction,purification and preparation of amylose complex with different degree of polymerization...