Research On The Microwave Detection Method Of The Quality Of The Liquid Food

Food safety problem is the biggest health problem human beings face, which is directly related to people’s life safety. The liquid food industry, one of the pillars of the food industry, is the easiest adulteration of fraud industry. Therefore, food’s quality inspection is particularly important. A detection method based on microwave can realize the non-contact, non-destructive testing, which has gained more and more attention. In terms of the theory of various substances having different attenuation of absorption to the electromagnetic wave, the attenuation of absorption to the electromagnetic wave of different components of the liquid is studied. And some liquid food(such as wine and milk) are studied experimentally.This paper, based on microwave detection principle, measured different components of the liquid in the frequency range of 3.94GHz-18 GHz for the microwave detection, including single solution of liquid material, binary mixed solution and a variety of substances. A new method of measuring liquid molecular radius based on the Debye equation provides the basis for the identification of single liquid substance. The substance of the liquid can be judged according to the calculation result of the radius.For the binary mixed solution, according to whether hydration occurs between two kinds of liquid molecular, it can be divided into two cases which were respectively detected to measure the absorption attenuation curve. The content of some substance in the methanol water solution or the acetone water solution can be found out according to the different absorption frequencies of the different solution. For the binary mixed solution of methanol and ethanol without the occurrence of hydration, through the absorption attenuation curve, some substance’s absorption frequency and the decrement under this frequency can be found out in order to determine whether the mixed liquid contains the substance and its content. For the mixed solution of multiple substances,experiments were conducted with adulterated liquor and the metamorphic milk. Based on the classification detection of different types of liquid food, this paper also provides a method for detecting all types of liquid food quality.This paper’s method based on microwave not only can be used for liquid food industry, but also can be extended to the chemical industry. It can be used to detect various chemical reagents, which has broad application prospects.