Abstract:

Chilling injury (CI) is the main factor limiting cucumber storage at low temperature. The goal of this research
was to use pre-harvest calcium applications to delay CI of “Ludi No.2” cucumber during cold storage at (4 ± 0.5) ℃,
aiming to provide reference data for cucumber transportation in early spring or winter. The results showed that chilling
injury index, malonaldehyde (MDA) content, relative conductivity, and free proline increased whereas firmness, soluble
solids, color and major volatiles of cucumber fruits decreased during cold storage. At the end of storage, calcium chloride
treatment at 0.75% and 1% showed the lowest CI index of 0.3. MDA content and relative conductivity of cucumbers treated
with calcium chloride at 0.75% and 1% (m/m) were significantly reduced as compared with those of controls stored at 4 ℃
（P < 0.05). Cucumbers sprayed with CaCl2 were firmer than controls. The more calcium was sprayed, the higher the
firmness was. Cucumbers sprayed with CaCl2 at 0.75% and 1% contained higher levels of soluble solid content (SSC), free
prolinet and major volatiles contents, and were greener and less sensitive to low temperature than controls. It is concluded
that the overall quality of cucumbers treated with calcium was better than that of controls. Taking all into account, 0.75% is
the optimal concentration. Also, cucumbers sprayed with calcium at 0.75% could delay the occurrence of CI by up to 4 days
and maintained its quality better during cold storage.

Key words: cucumber, preharvest calcium chloride sprays, cold storage, quality