Abstract:In order to study the relationship between freshness degree and dielectric properties of Lingwu long jujube, the dielectric properties parameters of long jujube were measured using (LCR)on 1.995 kHz, and the correlation analysis between dielectric properties parameters and quality parameters was conducted. The results indicated that correlations between long jujube’s dielectric loss factor ε″ and soluble solids content, hardness, weight loss, titratable acids content & MDA content were very significant (P<0.01), and the correlation between relative dielectric constant ε′ and respiration intensity was very significant (P<0.01). The long jujube were divided into three freshness grades according to the change rules of soluble solids content, hardness and weight loss rate. Using dielectric loss factor ε″ as the input characteristic parameters,the prediction model of long jujube freshness was established by BP neural network structure. The average distinguishing rate of freshness grades was 81.67%. The results indicated that the freshness degree of long jujube could be predicted by dielectric properties parameters.