Study On The Dielectric Property And The Non-destructive Testing Technology Of Malus Pumila Mill.CV.

Dielectric property is the corresponding reaction of the charge of biology molecular to the external electric field. Studying the dielectric properly of food is in favor of analyze and control its quality as well as to apply it to processing food. This technology is widely adopted and has its unique advantage in storage, electric processing, quality inspecting and grading. Inspection by using the electric physical property provides a major method to the automation and precision control of food processing.The paper is based on the methods and principle of NDT for the quality of the fruit on account of dielectric properties. We established the experimental system which can determine the dielectric property of apples through HIOKI-3532-50-LCR instrument. The best testing condition of the installation is tried to determine, the relationship between the different contour parameter, fresh, different corruption, different wound degree of falling situation, freezing degree and the change of dielectric properties are tested. The mathematical model equation is established with moisture content, TSS, organic acid content and capacitance, impedance and inductance of apple. To measure the internal quality of apple non-destructively by dielectric properties is feasible in theory.The optimal conditions to measure the dielectric property parameter of Malus pumila Mill. CV. are: the diameter of circular probes 8.0cm, the distance of two probes 7.0 cm, the frequency 3.3～3.6 MHz and the measuring voltage 1.0V.To analyze the change rule of dielectric property parameters with different shapes of apple, there is a certain correlation between the dielectric property and their shapes. A new idea to describe the shape of apple by using capacitance is proposed.By measuring the parameters of quality and dielectric property of apple during storage, correlations between capacitance, impedance, inductance and fresh indexes are studied. The results show that the significant correlation between capacitance, impedance, inductance and water content, TSS, organic acid content at frequency range (3.3-3.6MHz). The equations are: Finally. the internal qualities of apple can be deduced from dielectric property by those equations and the internal qualities can be measured non-destructivelyThe changing regulations of the dielectric properties of the apples at dissimilarly putrefied, hurt and refrigerated are studied. The results show that there are some different points compared with fresh apples and hurt apples and differed from the injured degrees and injured types. So, the putrefied or hurt degree of apple can be evaluated by the changes of dielectric property.