Fruit and Vegetable Quality

entation. Both types of investigators note major changes in quality degra-
dation during the food process or postharvest storage. Thus, both assume
that quality cannot be improved during processing or storage, merely
maintained. However, the postharvest physiologist differs in perspective
from the food scientist in that the former thinks of quality in terms of
maximization while the latter thinks in terms of optimization. The qual-
ity ideal of a specific fruit or vegetable is the premium cultivar, grown
under optimal conditions, harvested at peak maturity and consumed
within minutes or hours after harvest. Although quality is measured in
terms of specific characteristics (e.g., color, flavor or texture), it is gen-
erally described more in terms of acceptability (e.g., superior, good, fair,
poor).
In an attempt to develop ways of defining fruit and vegetable quality
in terms of the consumer, it has been necessary to challenge some of the
widely held assumptions of quality both by food scientists and posthar-
vest physiologists (Shewfelt, 1999). The Quality Enhancement (QE)
model (see Figure 8.1) has been proposed to redefine quality in terms
of the consumer and thus lead to improved quality of fresh fruits and
vegetables (Shewfelt, 1994; Malundo et al., 1997; Shewfelt et al., 1997).
This chapter highlights the major principles that form the basis for the
model and provides two examples of how the model has been applied.

Introduction 145

FIGURE 8.1Quality enhancement model. Reprinted with permission from Shewfelt et
al., 1997, Food Technology,51(2): 56–59.