The observed microbial load on blueberries which ultimately
dictates keeping quality is greatly impacted by the time and
method of harvest, as well as by local climactic conditions and the
post-harvest holding times and temperatures before processing.
During late harvest, microbial populations on fully ripened or
overripe berries are typically higher than earlier in the season
(Sabaratnam, Dickman, & Schilder, 2004), with various molds
including Colletotrichum acutatum (causal agent of anthracnose
fruit rot) easily spread to other uninfected berries during rain
events. Decreased blueberry firmness after harvest remains one of
the industry's most pressing concerns with NeSmith, Prussia,
Tetteh, and Krewer (2002) reporting that machine harvesting
decreased fruit firmness 20e30% compared to hand-picking.