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.

Excimer fluorescent ultraviolet (UV) lamps (UV–228) function as mercury–free sources that use excimer emissions as excitation light sources. First, we evaluated the effects of UV–228–based irradiation (λ_max = 228 nm) on the viability of fungi, using Penicillium digitatum, and compared these effects with those of other light sources, such as OEL–222 (λ_max = 222 nm) and GL–6 (λ_max = 254 nm), to evaluate the effectiveness of the excimer fluorescent lamp. Next, we investigated the effects of UV–228–based irradiation on strawberry storage. Although UV–228 affected weight loss, Brix, ascorbic acid, polyphenol, and DPPH, the effects of UV irradiation for 5 min on strawberry fruit quality were minimal; i.e., only weight loss and ascorbic acid content were higher than those in the non–irradiated treatment. We found that 5 min of UV–C irradiation using UV–228 prevented mold emergence for up to 11 days of storage in strawberries These results indicate that UV–228 contributes to long–term strawberry storage.