Ultrasonic Modification Of Pea Starch And Its Product Development

Modified starch has been widely used in various fields because of its excellent performance, and ultrasonic technique as modified starch physical emerging technology, has attracted more and more attention. This paper takes the pea starch as raw material, using hydrogen peroxide as oxidizing agent, ultrasonic assisted preparation of oxidized pea starch. Studies were conducted on the synthetic route, determine the best synthesis process parameters, to optimize the preparation technology of pea oxidized starch. At the same time, the structure,properties were studied, to provide reference for development of pea oxidized starch, provide the basis for the application of ultrasonic technology in modified starch production, in order to make better use of ultrasonic technology.This paper study the influence law of ultrasonic under different conditions on the pea raw starch viscosity changes, to explore the effect of ultrasonic treatment on the structural properties of the pea starch. The results are as follows:pea starch in ultrasonic frequency combination for 25 kHz+40 kHz+80 kHz,500W,45 ℃ and under the 60min effect the maximum peak viscosity decreased, the maximum of pea starch showed that ultrasonic effect.Using hydrogen peroxide as oxidant, ferrous sulfate as the catalyst for preparing oxidized starch, experiment study of pH, the influence of reaction temperature, hydrogen peroxide dosage, reaction time, ultrasonic power on the carboxyl content of pea oxidized starch reaction. The results showed that ultrasonic can obviously accelerate the oxidation, rate of reflection, so that significantly improve the rate. Finally get the optimal conditions of oxidized starch prepared:reaction pH 5, reaction time 90 min, ultrasonic power 500 W, ferrous sulfate addition 0.3%, hydrogen peroxide addition 15%.In addition, the structure and properties of pea modified starch of different processing conditions were investigated. The products were characterized by modern analysis instruments, analysis, particle surface morphology of the synthetic product by using scanning electron microscope results show that:the original starch granule surface is smooth, no holes, modified by ultrasonic assisted oxidation, starch granule surface roughness, holes, particles are more concentrated, closely together; X-X-ray diffraction and infrared spectrometer on the crystal structure of synthetic product were identified, the results showed that:the original structure types of no damage of starch molecules modified ultrasonic oxidation, the crystalline structure of the original is not damaged, but the peak diffraction intensity weakening characteristic. Studies the characteristics of Brabender Viscograph of paste application, the results show that the ultrasonic oxidation modified the starch paste decreased peak viscosity. And its thermal properties, size, transparency, solubility, freeze-thaw stability and retrogradation, whiteness and other physicochemical properties were detailed comparative study. The transparency, solubility, whiteness were significant increased, water absorption rate, particle size and starch are better than original starch decreased enthalpy.