Effects of Electron Beam and ⁶⁰Co γ-ray Irradiations on the Fresh-keeping of Winter Jujube

In order to prolong the shelf life of post-harvest winter jujube, the fruits were treated with different doses(500, 800 Gy) of electron beams and ⁶⁰Co γ-rays and then stored at 0±1℃ and 80%~85% relative humidity for 54 d. The effects of different irradiation treatments on the microbial quantity and the quality of winter jujube were investigated during cold storage. The results indicated that both irradiation treatments could effectively inhibit the increase of decay rate of winter jujube and the growth of microorganism. At the end of storage, the decay rate of the winter jujube in the control group had reached 47.87%, while that of the irradiated groups was between 20.97% and 25.95%, significantly lower than that of the control group. In the early 24 days of storage, irradiation treatment had no significant effect on the total soluble solid and titratable acid content of winter jujube, however irradiation treatment reduced the firmness of winter jujube and promoted the redness of pericarp. In the later 44 days of storage, irradiation treatment could restrain the respiration intensity of the fruits. In the above processing, two treatments of low dose 500 Gy could maintain good storage qualities of winter jujube.