Short period irradiation of single blue wavelength light extends the storage period of mature green tomatoes

• The storage qualities of tomatoes were improved by blue light pretreatment.
• Tomatoes maintained greater firmness with the blue light pretreatment.
• For short-term storage, mature green tomatoes ripened most quickly in darkness.
• Blue light pretreatment is an effective beneficial treatment for tomatoes storage.

Major postharvest quality factors of mature green tomatoes were investigated to improve their long-term storage. Mature green tomatoes pretreated with blue light (440–450 nm) emitted from blue light emitting diodes (LEDs) for 7 days developed a yellowish color and high levels of firmness, while those pretreated with darkness or red light (650–660 nm) from red LEDs for the same period ripened and developed red color. The pretreated tomatoes were incubated in darkness at room temperature, and a* and b* values, firmness and lycopene contents were measured after 7, 14, and 21 days of storage. The tomatoes pretreated with blue light had delayed softening; however, these tomatoes ripened fully, recovering red color development and accumulation of lycopene during 21 days of storage in darkness. These findings indicate that simple single blue wavelength illumination can be an effective application to extend the shelf-life of tomatoes by delaying fruit softening and ripening. Further studies should be conducted to characterize the roles and regulatory mechanisms of the components involved in the delay of tomato ripening by blue light.