Postharvest Treatments Affecting Sensory Quality of Fresh and Fresh-Cut Products - Postharvest Biology and Technology of Fruits, Vegetables, and Flowers - page 302

it relates to consumer acceptability (Shewfelt, 1999). Quality has been defined as “the
composite of those characteristics that differentiate individual units of a product, and have
significance in determining the degree of acceptability of that unit by the buyer” (Shewfelt,
1991). The key to increasing consumer consumption of fresh fruits and vegetables and
fresh-cut products, without loss of grower income, lies in providing produce with superior
flavor that lasts during an extended shelf life.
This chapter summarizes recent progress on postharvest (and some preharvest) methods
that affect sensory quality of freshly harvested and fresh-cut products.

14.2 Preharvest treatments

The ultimate potential postharvest quality and shelf life of fresh vegetables is determined
before harvest. Several variables that include the cultivar, weather conditions, irrigation
practices, fertilizer, and pest control programs affect the harvested quality of produce and
its sensory properties. Indoor production of fresh vegetables helps assure uniform crop
quality compared to outdoor production, because the plants are not exposed directly to
rapid changes in climate. On the other hand, vegetable cultivation in a greenhouse under
artificial conditions can also affect the organoleptic quality of the product. This is reflected
in different flavors compared with those found in field-grown vegetables (Gruda, 2005). The
soil type used for cantaloupe ( Cucumis melo ) production, as well as storage duration, can
affect postharvest sensory attributes of the fruit. Melons grown in sandy loam were lower
in sweet aromatic and sweet taste and higher in moisture release and fermented flavor than
the fruits grown in heavy clay soil. Fruity/melon, sweet aromatic, surface wetness, hardness
and moisture release attributes decreased while fermented and sour flavor increased during
storage, regardless of soil type. Clay soil appeared to have some advantages over sandy
loam soil in producing cantaloupe fruits with better sensory quality attributes (Bett-Garber
et al., 2005).
Fertigation is also a very important preharvest aspect that affects quality and sensory
attributes of fresh produce. In a recent study, strawberries were exposed to three different
levels of salinity. Fruit quality, characterized as taste, aroma, and texture by a consumer
panel, decreased by more than 24% with increasing salinity in one cultivar, but was unaf-
fected in a different cultivar (Saied et al., 2005). Neither sensory quality attributes nor the
composition of volatile compounds were affected by the planting density of apples ( Malus
×

domestica Borkh.) cultivars (Thybo et al., 2005) or canopy density of kiwifruit ( Actini-
dia deliciosa “Hayward”) (Snelgar et al., 1998). However, the variation in some sensory
flavor attributes between apple cultivars was correlated with the concentrations of volatile
compounds, of which the majority were straight-chain and branched-chain esters of fatty
acids with characteristic fruity and/or sweet notes (Thybo et al., 2005). In a different study,
the quality of apple fruits was evaluated under organic (ORG), conventional (CON), and
integrated (INT) growing conditions. Soil classification, rootstock, cultivar, plant age, and
all other conditions except management were the same on all plots. Fruit volatile production
and sensory panels were used to evaluate fruit quality. Consumer panels rated ORG and
INT apples to have equal or better overall acceptability than CON apples, partially because
of higher aroma volatiles (Peck et al., 2006).
Virtually, some of the postharvest quality factors are genetically controlled and can vary
with variety. Therefore, from a quality standpoint, cultivar selection may be an important