Postharvest Biology and Technology of Fruits, Vegetables, and Flowers

148 POSTHARVEST BIOLOGY & TECHNOLOGY OF FRUITS, VEGETABLES, & FLOWERS
Wills and Ku, 2002; Mir et al., 2004; Opiyo and Ying, 2005; Guillen et al., 2006, 2007).
Fruits regain the capacity to ripen after treatment, but ripening can be delayed by a second
application (Hoeberichts et al., 2002; Mir et al., 2004). Fruit treated at pink and light red
stages ripened properly after a delay (Hurr et al., 2005), while red ripe fruit had a longer
shelf life of only 1 day when treated with 1-MCP (Ergun et al., 2006a).
Marketing of tomatoes in bunches with the tomatoes still attached to the stem is becoming
more popular. 1-MCP has been found to inhibit the abscission of cherry tomatoes from
the vines (Beno-Moualem et al., 2004; Lichter et al., 2006). The concentration of 1-MCP
required to inhibit fruit abscission may be much higher, and this may negatively affect
the ripening pattern. In citrus plantations, ethephon sprays are conducted to enhance fruit
loosening, with an undesired side effect of leaf abscission. 1-MCP was found to inhibit leaf
drop without affecting the ability of ethephon to cause fruit loosening (Pozo et al., 2004).
7.3.8 Other climacteric fruit
Tropical fruits, in general, are fast ripening and possess very low shelf life. Tropical fruits
are also susceptible to chilling-injury development, and therefore, 1-MCP may be of great
potential benefit. As well, cold storage or controlled atmosphere facilities are lacking in
many tropical countries, and fruits are stored at ambient temperature. Guava, mamey sapote,
and mountain papaya are three exotics that have been tested with 1-MCP. Guava responded
to 1-MCP treatment with a twofold increase in shelf life, although at a high dosage (0.9
μL/L for 6 h or longer), the fruit failed to ripen (Bassetto et al., 2005). A similar effect was
observed in other fruits such as kiwifruit (Boquete et al., 2004) and papaya (Manenoi et al.,
2007), while some fruits, such as stone fruits did not appear to have an upper limit of 1-
MCP. Mamey sapote is a large fruit grown in Central America and the Caribbean that softens
rapidly after harvest. 1-MCP increased the shelf life of this fruit and also retained total acidity
without affecting soluble solids content (Ergun et al., 2005). Mountain papaya ripens
by rapid degreening followed by increase in respiration, ethylene production, and flesh
softening. 1-MCP prevented the increase in ethylene and partially inhibited softening and
color development in this fruit (Moya-Leon et al., 2004). The ripening of papaya is associated
with a strong and characteristic aroma due to increased production of esters and
alcohols (Balbontin et al., 2007). Ethylene (as ethrel) promotes and 1-MCP inhibits the
aroma component production in papaya.
Persimmon fruits treated with 1-MCP showed slower ripening and softening after reduction
in astringency (Harima et al., 2003; Salvador et al., 2004a; Luo, 2007). Cultivars
that are susceptible to chilling injury also had less internal gel formation, possibly because
of inhibited softening (Salvador et al., 2004b).
7.4 Physiological storage disorders
The effect of 1-MCP has been thoroughly investigated in reducing physiological disorders
of apples that occur during storage. Several studies were in relation to superficial scald,
since an interaction between ethylene production and α-farnesene was believed to be a
primary cause of scald development, and early reports indicated that 1-MCP inhibited
superficial scald development (Fig. 7.3) (Fan and Mattheis, 1999a, b; Rupasinghe et al.,
2000; Watkins et al., 2000). Superficial scald appears as a brown discoloration on the