ior during growth (production), storage and processing. This signifies
that the same dynamic product model can be used over and over for the
description and prediction of the intrinsic product quality at all condi-
tions in the integrated view of fruit and vegetable quality.
Assigned Quality
The quality of a product and its dynamic behavior during storage,
transport and distribution can be based on the behavior of all the intrin-
sic properties of a product that have a bearing on the quality perception
of the consumer or a specific group of consumers. If we know which
properties are used to arrive at an assigned quality (determination) and
how they are used (relative importance), quality behavior may be mod-
eled by modeling the appropriate properties. This information is known
as the “quality function” (Tijskens et al., 1994b; Sloof et al., 1996). Many
models have been developed, consciously or unconsciously, based on
this philosophy (Tijskens and Evelo, 1994c; Tijskens et al., 1994a,
1996a, 1996b; Verlinden, 1996).
EXAMPLES OF MODELING ACCEPTABILITY
When describing or modeling acceptability of (perishable) products,
one has to realize that consumers can assign quality to each product item
separately, e.g., the taste of one tomato. In acceptability, however, the
quality aspect is combined with the economic aspect. Consumers may
buy one individual tomato, but commercial applications inherently cover
complete batches of products. As such, within the aspect of acceptabil-
ity a second aspect comes into play: How many individual items in a
batch may be unacceptable before the batch as a whole becomes unac-
ceptable? This aspect introduces a system of population dynamics in the
description of batch behavior.
Acceptability of Potted Plants
The behavior of acceptability of batches of products has been mod-
eled for potted plants during storage in darkness (Tijskens et al., 1996b).
In the assessments of the potted plants, the applied quality criteria and
the quality limits were predefined and related among others to number
of leaves and flower without defects. The limit of acceptability has there-
Examples of Modeling Accetability 129