558 Produce Degradation: Reaction Pathways and their Prevention
18.8 CONCLUSION
All plant cells are surrounded by rigid cell walls. With adequate turgor and nutrients,
cell walls provide support to the plant, maintain structure, and give produce com-
modities their specific textural characteristics. Dehydration, physical damage, and
physiological change all contribute to the phenomenon of aging in plant tissues.
Aging wears down the defenses of the fruit or vegetable and opens a window of
opportunity for microbial or insect invasion. Specific measures can be taken to slow
the aging process, such as refrigeration, commodity-specific packaging, and various
postharvest treatments. None of the treatments are preventative measures; they
extend shelf life, which means that we are able to ship produce commodities world-
wide throughout the year.
Specific examples of produce degradation have been shown in scanning electron
micrographs in this chapter. Similarities between various plants include an intoler-
ance of dessication followed by rapid wrinkling of the outer layers and cracking of
the cuticle. The mesocarp may separate from the outer layers. At advanced stages,
the middle lamella degenerates and cells separate under strain. Finally, microbes
start invading the unprotected tissues.
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