Study On Synthesis Of Palm Oil Starch Ester And Its Sructure And Properties

Potato starch and palm oil is rich in resources, and has great value of development and utilization. In the paper, study on synthesis of palm oil starch ester and its structure and properties with potato starch and palm oil as raw materials, and lay the foundation for its application.Study the effect of potassium hydroxide dosage, reaction temperature, reaction time and power ultrasound on palm oil ultrasonic hydrolysis and its parameter optimization. The suitable reaction conditions for the ultrasonic hydrolysis of palm oil were as follows: the reaction tempreture is 50 ?, the amount of potassium hydroxide is 50%, the reaction time is 50 min, the ultrasonic power is 600 W. Gas chromatography-mass spectrometry analysis showed that fatty acids composition of product were as follows: relative content of oleic acid is 42.140%, the relative content of palmitic acid is 39.314%, the relative content of linoleic acid is 10.760%, and the relative content of stearic acid is 5.412%.The potato starch was pretreated with sodium hydroxide and urea. The results of single factor experiment and orthogonal experiment showed that the optimum technological parameters were as follows: the ratio of sodium hydroxide to urea is 2, the dosage of sodium hydroxide and urea is 12%, the pre-cooling temperature is -9?, the amount of ethanol is 110 mL. And the solubility of cold water in this condition is 97.02%. Results of synthesis of palm oil starch ester found that the optimal reaction conditions for starch ester of palm oil wre as follows: the ratio of starch to fatty acidss is 1:5, the reaction time is 5 h,the reaction tempreture is 150?, the amount of hydrochloric acid is 0.10%. And the degree of substitution of the reaction reached 0.02596 under this condition.Scanning electron microscopy analysis, it was found that the native potato starch granules surface was smooth, no holes. After pretreated, the starch granule surface was rough, not smooth. The damage degree and the wrinkles of the palm oil starch ester granules surface were increased, the small particles were attached to the surface of starch granules, and some tiny holes appeared on it. Infrared spectrum analysis indicate that pretreatment starch did not induce the increase and loss of functional groups, and the original structure of starch was not changed, the palm oil starch ester had a typical ester bond characteristic absorption peak at 1740.12 cm-1. After pretreatment and esterification modification, the peak viscosity decreased and the cold and thermal stability of viscosity were increased compared with that of the native potato starch, the cold and thermal stability of palm oil starch ester was the best. And their solubility, emulsification, freeze-thaw stability, retrogradation resistance were increased compare to that of native potato starch.