Effect Of Ultrasonic Treatment On Structure And Properties Of Starch

In this paper, the maize starch was used as the raw material, it was treated by three-frequency ultrasonic, and dual-frequency ultrasonic and single-frequency ultrasound in the different system. The relationship between these changes, ultrasonic parameters and environmental factors and the mechanism of effect of multi-frequency compound ultrasonic was revealed by the DSC, SEM, XRD etc. And they were compared with which was treated by single-frequency ultrasound. The purpose is to provide theoretical guidance for the physical field of a green non-polluting technology-multi-frequency ultrasonic technology. The results show that:The peak viscosity of original starch is1076.OBU. In the ethanol system, the peak viscosity of starch was treated by single-frequency ultrasound reduced14.50%at least, the peak viscosity of starch was treated by dual-frequency ultrasound reduced16.00%at least; the peak viscosity of starch was treated by the tri-band ultrasonic reduced21.65%. In the water system, the peak viscosity of starch was treated by single-frequency ultrasound reduced16.91%at least, the peak viscosity of starch was treated by dual-frequency ultrasound reduced19.14%at least, the peak viscosity of starch was treated by tei-band ultrasound reduced19.98%. In the acid system, the peak viscosity of starch was treated by single-frequency ultrasound reduced23.42%at least, the peak viscosity of starch was treated by dual-frequency ultrasound reduced40.15%at least, the peak viscosity of starch was treated by tei-band ultrasound reduced78.25%. The first to achieve maximum transparency was the starch was treated by tri-band ultrasonic, the last was the starch treated by single frequency ultrasound. Hardness, brittleness, elasticity, cohesiveness, stalemate degree, chewing degrees and recoverability of the starch are a reducing trend after treated by ultrasound. Enthalpy value of starch tends to decrease in order:tri-band ultrasound, dual-frequency ultrasound, single-frequency ultrasound. The freeze-thaw stability of starch was reduced after ultrasonic treatment, and it was changed obviously after treated by tri-band ultrasonic.The crystal of native starch is not damaged, but its characteristic diffraction peak intensity was significantly reduced, diffuse diffraction features gradually increased, It was shown crystal lattice ordering degree of starch was reduced. The crystallinity of starch treated by tri-band ultrasonict was reduced the most obvious in the ethanol system, water system, acid system., The particle was irregular polyhedron and the surface appears somewhat lighter injuries after the single-frequency ultrasonic treatment; there are more, deeper hole after treated by dual-frequency ultrasound treatment; there are numerous and deep holes on the surface of particles treated with tri-band ultrasonic.The non-frequency supersonic cavitation yield amount decrease is in turn:the three-frequency ultrasonic, the dual-frequency ultrasonic, the single-frequency ultrasound. It was shown from the cavitation bubble movement was simulated through the matlab and the detection of cavitation effect, The amount of cavitation events by a single frequency, dual-band, multi-frequency ultrasonic sequence of increments at the same time.