Study On The Solubilization Properties Of The Amphipathic Starch Reverse Aggregates

In this paper,a series of amphiphilic starch alkyl esters were synthesized by introducing the alkyl groups with hydrophobic association into the starch molecules.The properties of the reversed aggregates in the organic solvent and solubilization properties of protein in reversed aggregates were studied.The results showed that the Wo value,viscosity,surface tension and particle size of the starch alkyl ester in the isooctane/n-octanol mixed solvent were summarized and the effect factors of the solubilized protein were investigated.The details were listed as follows:1.Starch alkyl esters were prepared by introducing hydrophobic alkoxy groups into starch molecules with butyryl chloride,octanoyl chloride and lauroyl chloride as esterifying agents.The results showed that the introduction of hydrophobic alkyl groups increased the solubility of the product in organic solvents.The structure of the starch alkyl ester was characterized by FT-IR and XRD,and the thermal stability was analyzed by TG.The relative molecular weight was determined by HPLC.2.The organic solvent was selected and the reversed aggregates were prepared by using a series of starch alkyl esters.The Wo value,viscosity,surface tension and particle size distribution of the reversed aggregates were studied.The results showed that starch octanoate and starch lauric acid ester could form reverse polymerization system in isooctane/n-octanol solvent.The Wo value and viscosity of starch octanoate and starch laurate were increased with the increasing amount of water and the concentration of surfactant.Besides,the viscosity of starch laurate increased sharply with the increase of water,which was not suitable for protein solubilization.The surface tension of starch octanoate reversed aggregate solution increased with the increase of the degree of substitution and starch octanoate concentration.The particle size analysis of starch octanoate reversed aggregates showed that the particle size range was 90-270nm.Increasing the concentration of starch octanoate reversed aggregates,the diameter of the opposing aggregates increased as well.3.The solubilization properties of the protein and the influencing factors(peptone addition,starch octanoate concentration,extraction temperature,extraction time,etc.)were also studied.The results showed that the optimal condition for collecting the protein in the reversed aggregates solution was when the dosage of peptone was 0.02 g/ml,the concentration of reverse micelle was 6mg/ml,the temperature was 35 ?,the extraction time was 30 min,the oscillation speed was 100 r/min,and the pH of buffer solution was 7.And protein solubilization could reach 64.56%±1.21%.