Moisture loss is the major cause of firmness change during postharvest storage of blueberry

Blueberry softening is known to be influenced by cell wall modifications accompanying ripening but these changes appear to be largely complete by the time of harvest. In this study postharvest storage conditions were controlled so only the extent of water loss varied between treatments. A linear relationship between weight loss and loss of firmness (as assessed by a non-destructive compression test) was demonstrated. This relationship did not hold at very low weight loss, where instead, firming of blueberries during storage was found. Magnetic resonance imaging of berries confirmed significant shrinkage and loss of water in berries which had high weight loss, compared with more subtle effects on sub-epidermal water content in berries with very low weight loss. Treatments which restrict blueberry water loss to below 8% are likely to be beneficial in retaining acceptable berry firmness for up to three weeks’ storage.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Weight loss was manipulated independently of other storage conditions. ► Blueberries that lost up to 1.34% weight demonstrated firming. ► For weight lost >3.47%, softening response was linearly related to weight loss. ► Magnetic resonance imaging confirmed shrinkage in high weight loss fruit. ► Results support a casual effect of weight loss on firmness for blueberries.