QUALITY PRINCIPLES
One of the limiting factors in postharvest research is the lack of un-
derstanding of consumer behavior. Many uncertainties about accurate
measurement of consumer response and the ability to apply such knowl-
edge to commercial situations have limited study in the area. Progress
in this area will require approaches and specific methods to determine:
(1) the relevance ofmeasured qualitycharacteristics toactual consumer
acceptability;(2) a common understanding of termslike food quality,
shelf stability and consumer acceptability among chemists, engineers,
postharvest physiologists and sensory specialists; (3) quantitative as-
sessment of consumer acceptability, (4) under what conditions con-
sumers are valid assessorsof quality and acceptability and when are
they not; (5) types of assessment toolsneeded to differentiate between
defect and excellenceorientations of quality characteristics; and (6) how
factorsthat affect consumer acceptability that are intrinsic to the prod-
uctcan be separated from thosethat are intrinsic toindividual con-
sumers.Several principles described in the scientific literature provide
clues to new approaches, but little work in these areas is currently being
conducted.
The relevance of quality to consumer acceptabilityas quality is nor-
mally measured has been questioned (Pendalwar, 1989). Selection of
quality criteria for evaluation is frequently based on the accuracy and
precision of the results rather than on relevance to acceptability in the
marketplace (Shewfelt and Phillips, 1996). Too often quality and ac-
ceptability become merely buzzwords that have no real meaning within
the scientific community. Measurements of quality characteristics rep-
resent an emphasis on “internal validity” (accuracy and precision of the
quality characteristics measured) of the research data (van Trijp and
Schifferstein, 1995), but acceptability requires “external validity” (abil-
ity to predict performance of a product in the marketplace) to be com-
mercially significant. To establish true relationships between quality and
acceptability studies must merge the concepts of internal and external
validity.
A common understanding of termslike food quality, shelf stability
and consumer acceptability among chemists, engineers, postharvest
physiologists and sensory specialists would permit a more concerted re-
search effort on improving fresh fruit and vegetable quality. A major
difficulty in understanding quality is a lack of a common language. Nu-
merous definitions exist for quality (Kramer and Twigg, 1970; Pirsig,