Apples - Crop Post-Harvest: Science and Technology - page 94

enhanced physiological disorders on some apple varieties.
The management of these is still being investigated and
is yet to be resolved. It should be noted that 1-MCP is not
a substitute for other correct postharvest handling, storage
and transport practices. Correct temperature management
is still paramount in maintaining quality fruit.
The major goal in applying research on fruit ripening
such as 1-MCP is to create a healthy and pleasurable eating
experience for the consumer. It is important that technolo-
gies such as 1-MCP that improve storability or any other
single factor, do not negatively impact on consumer
satisfaction. Aroma production in ripening fruit is gener-
ally dependent on ethylene action and therefore 1-MCP
application can alter the aroma profile. In general, volatile
production is lower in 1-MCP treated fruit (Kondo et al .
2005), but this is dependent on the timing and harvest
maturity of the fruit (Mattheis et al . 2005). Similar
results have been observed following CA storage, where
CA suppresses ethylene and respiration, which in turn
suppresses aroma development (Mattheis et al . 2005). On
the other hand, when applied at the correct time and
concentration 1-MCP treated apple fruit have been shown
to possess a more acceptable aroma than control fruit
(Lurie et al . 2002). Fruit quality involves integration of a
range of quality and sensory parameters. In a recent study,
the effects of 1-MCP on consumer acceptance related the
well-known effects of 1-MCP on apple fruit (firmness,
soluble solids and titratable acidity) to the sensory and
organoleptic ratings (overall odour, fruit odour, sweet,
sour, ripe, firm, crisp, juicy and mealy) (Pre-Aymard et al .
2005). They showed that consumers placed a high value on
apple fruit texture and that correct 1-MCP treatment can
maintain the texture characteristics that are preferred by
consumers (Pre-Aymard et al . 2005). This relationship to
the consumer is often the critical limiting step to applying
our knowledge of fruit quality and ripening. Such studies
are important because consumers who have a negative
experience when purchasing apples are likely to change
varieties, purchase less or purchase something different
(Harker et al . 2003).
The effect of 1-MCP on other aspects of apple storage is
still to be investigated. For example, there are opportunities
to investigate the role of 1-MCP and ethylene in apple
fruit pathology. There are conflicting reports on the role of
ethylene and 1-MCP in apple storage decay.

person is about two to three apples per week (Peneau et al .
2006). However, there is also an increase in the range of
choices a consumer can make when purchasing fruit and
other snacks, and so it is becoming increasingly important
for apple growers to understand the preferences of apple
consumers (Harker et al . 2003).
Consumers have both emotional and sensory expecta-
tions of apples (Lund et al . 2006). Research suggests that
consumers easily recognize the appearance of the apple
varieties they prefer and the association between eating
experience and variety are firmly established for regular
consumers of apples (Jaeger et al . 1998).
In terms of the sensory quality of apples, consumer
preferences are based on interactions between texture and
taste (Harker et al . 2003; Lund et al . 2006). Taste, aroma
and freshness are the most important attributes taken into
account by consumers when choosing an apple (Peneau
et al . 2006). Most consumers prefer apples to be crisp and
juicy rather than mealy and soft. Mealiness is the degree to
which the flesh breaks down to a fine lumpy mass and is
a significant negative attribute of apple quality (Andani
et al . 2001). These negative characteristics develop as fruit
age during storage. Another interpretation of this change
is that consumer preferences within a single apple variety
are usually defined by the stage of ripeness of the fruit
(Harker et al . 2003).
It is very difficult to objectively measure the quality
attributes of apples in relation to consumer preferences.
The problem is that there is a high level of variability
between consumers and within a population of fruit
(Harker et al . 2003). This means that the 95% confidence
limits defining the relationship between an objective
parameter and a sensory perception are often large (Harker
et al . 2006). For example, Harker et al . (2006) found that
samples of apples had to vary in firmness by more than
12 N puncture force (Effegi penetrometer, 11 mm tip)
before consumers could perceive a difference in sensory
quality. Industries often try to set grade standards based on
penetrometer readings for firmness but the variability
within the apple sample and the differences in consumer
perception of firmness makes defining a minimum level
very difficult.
A consumer's perception of “quality” is the result of a
cascade of choices based on several factors including
previous experience, price, perceptions of freshness and
food safety (Lund et al . 2006). As a result sensory research
is focussing on developing preference maps and other
multivariate techniques to gain a better understanding
of how segments of consumers have differing responses
(Harker et al . 2006; Peneau et al . 2006). Specific flavour

Sensory requirements of apples
Fruit and vegetables are becoming increasingly valued as
an important part of a healthy diet. Research in Europe has
shown that the average rate of consumption of apples per