Long-Term Blueberry Storage by Ozonation or UV Irradiation Using Excimer Lamp

Blueberries are in high demand worldwide because of their taste and functional components. However, the shelf life of blueberries is short owing to their perishability and rapid quality deterioration. Therefore, a sterilization technology must be developed that can extend the shelf life of blueberries while maintaining their appearance and taste. As such, we verified the effectiveness of three pre-storage sterilization treatments (UV-C, ozone gas, and ozone water) using mercury-free excimer UV lamps that did not adversely affect the environment. We then created a device that continuously treated blueberries with approximately 2.57 ppm of ozone gas to ensure sterilization during the storage period, and we verified the effectiveness of the device. We found that the pre-storage ozone treatment reduced the number of fungi on the blueberry surface without adversely affecting fruit quality. The continuous ozone treatment suppressed the decrease in anthocyanin content, further reduced the number of fungi on the fruit surface and maintained fruit appearance for a longer period compared with the control. This suggests that continuous low-concentration ozone treatment suppresses the decay and extends the storage period of blueberries intended for raw consumption.