Abstract:

Blueberry fruit softening and softening indices change during storage were analyzed. Results showed that decay
index, titratable acid content, POD activity, Cx activity and β-Gal activity were closely related with firmness during storage
at room temperature. Among them, decay index and Cx activity showed highly significant negative correlation with firmness,
whereas there was a significant positive correlation between the content of titratable acid and firmness. Firmness and titratable
acid content decreased slowly, whereas decay index rose during cold storage at 0 ℃. POD activity, Cx activity and β-Gal
activity showed an obvious increasing trend along with decreasing firmness. POD activity and Cx activity rose rapidly in the
last stage of storage. Their activity peaks occurred on the 60th day of refrigeration at 0 ℃, while β-Gal activity climax occurred
in the early stage of storage and then its activity kept at a high level. Compared with fresh blueberry, blueberry refrigerated for
30 days showed smaller decreases in firmness and titratable acid content, less changes in decay index, POD activity and Cx
activity and no significant β-Gal activity climax after 4 days of storage at room temperature. From the above results, it can be
seen that blueberry refrigerated for 30 days can keep its quality for 4 days at room temperature.

Key words: blueberry, refrigeration, shelf life, softening