The dielectric properties of the raw Caixin, texture improvement agents (sodium alginate, calcium chloride and potato starch), color protecting agents (sodium chloride, edible glycerol and sodium carboxymethyl cellulose) and vacuum packaged Caixin after 27.12 MHz RF treatment are summarized in Table 1. The dielectric constant (ɛ′) and the loss factor (ɛ″) of vacuum packaged Caixin were both too high (9999) to be measured accurately. Therefore, it was diluted with deionized water to 100-fold and the ɛ′ and ɛ″ were 83.14 ± 0.81 and 43.27 ± 4.10 respectively. The ɛ′ and ɛ″ of raw Caixin were 77.61 ± 3.10 and 718.91 ± 19.94 respectively, which were significantly lower (P < 0.01) than that of vacuum packaged Caixin. Table 1 suggested that the high dielectric constant (ɛ′) and loss factor (ɛ″) of vacuum packaged Caixin might come from the salt and other agents added in the package. Similar results were also observed by Marra et al. (2009) and Birla et al. (2008) and they suggested that it is mainly the addition of salts that have increased the ionic conductivity and the loss factor of materials. The high ɛ′ and ɛ″ of vacuum packaged Caixin might be helpful to the temperature increment during the RF process. Fig. 2 shows that the electrical conductivity of vacuum packaged Caixin after RF heating also increased significantly. This might be because the RF treatment promoted the elution of soluble components and ions from the vegetable samples.