Research on the Relationship between Freshness and Dielectric Spectrum of Postharvest Ling-Wu Long Jujubes

In order to seek the feasibility of freshness prediction of Ling-Wu long jujubes based on dielectric spectrum, the electrical parameters of Ling-Wu long jujube were measured dynamically using HIOKI 3532-50 LCR parallel-plates measuring instrument. The concept of dielectric freshness F was put forward and its freshness index TI was proposed according to local standards. The results indicated that there was significant linear correlation between F value and TI (R2=0.709). The freshness prediction model of Ling-Wu long jujubes was established using the BP - ANN neural network (R2=0.894), the grade recognition rate was up to 82.14%. Freshness prediction of postharvest Ling-Wu long jujubes based on its dielectric spectrum was feasible.