Postharvest Biology and Technology of Fruits, Vegetables, and Flowers

146 POSTHARVEST BIOLOGY & TECHNOLOGY OF FRUITS, VEGETABLES, & FLOWERS
MiExpA1, has also been found in mango, and its expression was also inhibited by 1-MCP
(Sane et al., 2005).
The change in skin color of bananas from green to yellow indicative of chlorophyll
degradation was inhibited by 1-MCP. However, the color changes during ripening of 1-
MCP-treated fruits are not uniform, having disrupted or incomplete and uneven yellowing
(Golding et al., 1998; Harris et al., 2000; Macnish et al., 2000). This may be a limitation for
the use of 1-MCP on bananas. As well, application of 1-MCP after an ethylene treatment
of fruits was unsuccessful in circumventing this problem (Pelayo et al., 2003). As well,
due to the physiological variation even within a bunch, there was considerable variation in
responses of the fruit. In another study using propylene to induce ripening, application of
1-MCP 24 h after propylene treatment inhibited both color and volatile production, but not
ethylene or respiration (Golding et al., 1998).
7.3.4 Pear
1-MCP has been tested for its effectiveness on summer and winter pears. Pear fruit requires
an exposure to chilling temperatures before they begin to ripen. Winter pears require as
much as 8 weeks at low temperature before they ripen. Winter pears soften and develop a
buttery texture, while summer pears better retain their crispiness after they ripen. 1-MCP
treatment delayed or prevented softening, the degree of response depended on the cultivar
and the concentration of 1-MCP applied (Baritelle et al., 2001; Argenta et al., 2003; Hiwasa
et al., 2003; Kubo et al., 2003; Calvo and Sozzi, 2004; Ekman et al., 2004; Trinchero et al.,
2004). An effective concentration that can delay ripening without preventing the process
was 0.2 μL/L (Calvo and Sozzi, 2004; Moya-Leon et al., 2006). As in other green fruits, the
change in peel color from green to yellow was inhibited as well as ethylene production and
respiration (Argenta et al., 2003; Hiwasa et al., 2003; Kubo et al., 2003; Ekman et al., 2004;
Larrigaudiere et al., 2004; Trinchero et al., 2004; Mwaniki et al., 2005). The soluble solids
content was not affected in pears after 1-MCP treatment, while changes in total acidity
were inconsistent (Argenta et al., 2003; Calvo and Sozzi, 2004; Larrigaudiere et al., 2004;
Trinchero et al., 2004). In a sensory evaluation on “Packham’s Triumph” pears, the flavor
and aroma profile of 1-MCP-treated fruit stored in air were preferred over CA-stored fruit
(Moya-Leon et al., 2006).
There is variability in concentrations of 1-MCP that delay but do not prevent pear
ripening. Application of 0.2 μL/L resulted in normal ripening with no overripening (Calvo
and Sozzi, 2004; Moya-Leon et al., 2006), while concentrations as high as 10 μL/L resulted
in maintenance of optimal eating firmness for extended periods (Kubo et al., 2003). The
efficiency of ethylene to reverse 1-MCP effects was dependent on the concentration of
1-MCP application and the length of time the fruit had been stored (Argenta et al., 2003;
Calvo and Sozzi, 2004; Ekman et al., 2004).
7.3.5 Peach and nectarine
Responses of fruit to 1-MCP are affected by concentration and exposure period, but are
not dependent on treatment temperature (Liguori et al., 2004). Inhibition of fruit ripening
by 1-MCP was not persistent; however, repeated applications of 1-MCP helped maintain
suppression of ripening (Liu et al., 2005). The transitory effect of 1-MCP was not due to any