The Preparation And Application Of Stearic Porous Corn Starch Ester

It was studied in this thesis the preparation of stearic porous corn starch ester by esterification in dry processing, which was made from porous corn starch by enzymatic hydrolysis.The properties, structure and applications in the food were researched too.Firstly, porous corn starch was obtained from corn starch by enzymatic hydrolysis. Using a complex enzyme (Glucoamylase:α-Amylase=3:1) which was dissolved in buffer solutions, pH was 4.6, after 24h reaction, NaOH was joined in order to end the reaction. The porous corn starch could be got after centrifugal sedimentation, washing and drying.Secondly, stearic porous corn starch ester was prepared from porous corn starch in dry processing. In the single factor experiments, the effects of the varieties of factors on the degree of substitute (DS) and reaction efficiency (RE), which include initial content of water, the quantity of stearic acid and HCl, the temperature and time of reaction were researched. According to those results, the perpendicular experiments were designed to optimize the technology. The most optimum conditions were as followed: porous corn starch was 100g (w/w), initial content of water was 21%, reactive time was 5h, reactive temperature was 160℃, HCl was 0.0584% (w/w), stearic acid was 3% (w/w). The DS of the production was 0.007828, RE was 45.82%, the whiteness was 84.4%. The capacity of adsorption oil was 87.65%, which increased 45.94% than porous corn starch.In addition, the capacities of adsorption oil of corn starch, porous corn starch, stearic porous corn starch ester were compared. The results of lycopene adsorption and desorption experiments showed that stearic porous corn starch ester was better than prorus starch, and more stable after adsorption. The structures of starches were researched with modern instruments. The hydroxyl bond was substituted by stearic acid in Infra-red spectrometris pictures. The reaction mainly occured at amorphous region,which was revealed in X-ray diffraction and SEM photos. Specific surface area of stearic porous corn starch ester is bigger than porous corn starch, which is better than corn starch by specific surface area testing.Finally, the powdered oil was made from stearic porous corn starch ester, and the application in the sponge cake was discussed. The results showed, the salad oil was protected from powdered oil, and the sponge cake which with 20% powdered oil had high score than traditional cake on evaluate grade.