586 Produce Degradation: Reaction Pathways and their Prevention
oxygen, or at low temperature conditions significantly reduced the production of
volatile compounds, which occurs as the cell wall is ruptured [197]. In contrast,
injury to apples could result from external CO 2 , which causes loss of cytoplasmic
integrity, coagulation of the protoplast, the loss of organelle structure, and disinte-
gration of the cell wall. Additionally, undigested starch can be found in cells of
affected fruits at the hypodermis–cortex boundary [198]. Exposure to exogenous
ethylene in watermelon fruit causes activation of cell wall-degrading enzymes and
pectin depolymerization. In citrus fruits, continuous exposure to ethylene results in
a marked increase in endo-1,4-β-galacturonase (cellulase) and polygalacturonase
activities in the calyx abscission zones [199–201].
During storage, ‘Ceccona’ apricots treated with 1-methylcycloprene for 12 h at
20°C showed delayed softening and as well greatly reduced α-D-galactosidase and
beta-D-galactosidase activities [202]. In avocado fruits, 1-methylcyclopropene treat-
ments delayed the ripening and slightly reduced the depolymerization of cell wall
matrix polysaccharides hemicellulose andxyloglucans [203]. Many references are
found in the literature concerning the effect of gibberellic acid, jasmonate and
polyamine treatments of produce and their positive impact on the fruit’s storage life,
the ability to suppress mold decay, and the reduction of chilling injury [204–207].
Fumigation as well as irradiation has also been suggested as a measure to control
postharvest decay and infestation [208–210]. The enzyme catalase has also been
reported to function as an antioxidant in the defense response of mandarin fruit to
chilling stress. It is believed that heat conditioning may induce catalase activity
[211]. Other investigators have reported that hot water treatment (44°C for 15 min)
of ‘Royal Gala’ apples was very effective for controlling insect pests [212].
Under continuous illumination of low-intensity white light, spinach leaves
showed increased availability of soluble carbohydrates, especially glucose [213].
Textural changes were more apparent at the preclimacteric stage in the ripening
of the sapote mamey fruit, but the fruit pulp softening was not dependent on
pectinmethylesterase, polygalacturonase, or β-galactosidase enzyme activity [214].
Produce quality is directly related to biochemical components such as cell wall
polysaccharides and their composition, particle size, shape, moisture content, and
mechanical properties. Abiotic factors such as soil moisture, temperature, relative
humidity, and nutrient availability directly influence texture, flavor, color, and fresh-
ness of fruits and vegetables [112]. There are a number of factors that can render
serious damage to produce. The producers, processors, and transporters can use
common sense and simple approaches to minimize produce damage and the subse-
quent economic loss and can still deliver the best-quality produce to the consumers.
Extended exposure to water can induce hydrolytic activities in produce, which causes
quicker ripening and thus much shorter storage time. Since mature fruits contain the
enzymatic machinery to metabolize soluble sugars [215], high temperature and high
humidity can accelerate the process of ripening and cell wall softening, leading to
early loss of texture and flavor. Mechanical damage or bruising during postharvest
handling could activate the production of carbohydrolyases, leading to cell wall
degradation, which compromises fruit texture and flavor due to the breakdown of
sugars. Exposure to high winds can cause dehydration in fruits and vegetables,
triggering the production of chlorophyllase, which degrades chlorophyll and results