344 Produce Degradation: Reaction Pathways and their Prevention
health risks more than does a lower consumption of fruits and vegetables, but let us
save this discussion for later. In terms of environmental benefits, pesticides allow
food to be produced on less land, and thus more land can be devoted to wildlife
habitat, environmentally fragile lands can idle, and less water is needed for irrigation.
Increased domestic production results not only in lower produce prices, and
consequently higher consumption, but also in other economic benefits, such as
increased export and the ability to spend more money on items other than food.
Thus, without practical, effective, and economically viable alternatives, the elimi-
nation of pesticide use would probably result in serious problems. For instance, an
economic study from 1995 [10] estimates that complete elimination of pesticides
used in the U.S. on fruits and vegetables would increase wholesale prices by 45%
(retail prices by 27%) based on a 75% increase in unit production costs. The U.S.
production would be reduced by 16%, exports would decrease by 27%, and imports
would increase by 7%. Consequently, produce consumption would decrease by 11%
and acreage required for production of fruits and vegetables in the U.S. would
increase by about 44%.
Another important aspect associated with pesticide use is improved produce
quality, yielding larger products with better nutritious quality (e.g., due to a lower
competition from weeds), and also fruits and vegetables free from insects, surface
blemishes, scars, punctures, or other damage caused by pests. Apart from the less-
attractive appearance of damaged products, surface (cuticle) damages open the door
to further degradative changes, moisture loss, and also bacterial and fungal coloni-
zation, resulting in microbial spoilage of produce and a potential health risk to
consumers due to the possible presence of pathogenic microorganisms and toxins
they may produce. Moreover, many pests, such as insects, nematodes, and mollusks,
serve as vectors for plant and food-borne diseases. Thus, pesticides play an important
role in produce preservation and safety by preventing or reducing primary and
secondary microbial contamination. Other chapters in this book describe further
degradative changes associated with mechanical injuries of produce, mechanisms of
microbial spoilage, and attachment of human pathogens to fruits and vegetables.
The main focus of this chapter relates to the role of pesticides in preventing these
adverse consequences of pest attacks and in addressing other problems involved
with produce production.
With respect to the positive effect of pesticides on food safety, it has also been
suggested that pesticides may reduce the levels of naturally occurring fungal and
plant toxins that may actually pose greater cancer risk than synthetic pesticides
[11,12]. In the case of mycotoxins, the link between pesticide use and a decrease
in fungal toxin production is relatively clear. Fungicides can control toxin-producing
fungi, such as Aspergillus flavus or Aspergillus parasiticus in the case of aflatoxins,
thus reducing mycotoxin levels [13,14]. Also, the application of insecticides or
nematicides may indirectly contribute to decreased mycotoxin production by reduc-
ing crop damage that predisposes plant tissues to fungal invasion and/or through
control of insects that spread the fungal infestations [15,16].
Natural plant toxins, also called phytoalexins (phyton = plant, alexin = defend)
are considered a means of natural defense against pests. Notable phytoalexins include
the glycoalkaloids produced by potatoes (solanine and chaconine) and tomatoes