Phospholipase D Inhibition Technology for Enhancing Shelf Life and Quality - Postharvest Biology and Technology of Fruits, Vegetables, and Flowers - page 244

( Continued )

Table 10.1

Treatment—
preharvest Treatment—postharvest

Commodity spray spray or dip Effects

Tomato (mature
green stage,
postharvest dip)

Nil Hexanal

compositions—1%, 2%,
3%; air storage, 12 ◦ C

Shelf life extended to nearly
2 months, increased firmness of
ripe fruits

Fresh-cut vegetables
(carrots, celery,
cauliflower,
cucumber, etc.)

Nil Hexanal composition—1%;

air storage, 4 ◦ C

Improved shelf life and quality

Carnations Nil Hexanal vapor (0.01-0.05%

w/w); air storage, 25 ◦ C

Delayed senescence

Roses Nil Hexanal vapor (0.01-0.05%

w/w); air storage, 25 ◦ C

Delayed senescence

Chrysanthemums Nil Hexanal vapor (0.01-0.05%

w/w); air storage, 25 ◦ C

Delayed senescence

In the hexanal formulation, hexanal alone is the active ingredient. The hexanal composition, also referred to as
an enhanced freshness formulation (EFF), also contains other ingredients (Paliyath and Murr, 2007). Treatments
are provided as preharvest sprays, postharvest dips, or hexanal vapor treatments.

do not reduce the color or flavor development of tomatoes during further storage, but
provide improved firmness. The effects of several trials on different produce are shown in
Table 10.1.
Several aspects of this technology are under optimization. A combination of several
active ingredients potentially provides beneficial effects by reducing deterioration by mul-
tiple mechanisms (Paliyath and Murr, 2007). For instance, a combination of PLD inhibition
and the use of antioxidants would reduce phospholipid degradation as well as downstream
oxidative processes. A total inhibition of PLD may be lethal, and a partial inhibition may
provide added benefits. Inhibition of PLD activity by 30-40% through antisense PLD
approach enhances several beneficial qualities (Chapter 9). Through the application of
hexanal or its formulations, only a partial inhibition of PLD may be achieved. It is hypothe-
sized that such an inhibition will reduce the requirements for carbon substrates to replenish
the lost phospholipids through biosynthesis. This spared carbon sources then can be mo-
bilized to the biosynthesis of beneficial quality, enhancing components through metabolite
channeling as described in Chapter 21. The use of hexanal is also compatible for organic
produce, as there are no postharvest treatment procedures available for organic produce
currently. The PLD inhibition technology using hexanal is licensed to AgroFresh Inc., PA.

References

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Chapman, K.D. and Shea, A.-B. 2007. Methods for extending the freshness of cut flowers, ornamental trees, and
plant cuttings. US patent #7,199,082.
Cornell University College of Agriculture and Life Sciences. 2002. Prevention of softening in apples. Available at:
http://www.nysaes.cornell.edu/fst/faculty/hrazdina/projects/PreSoftApple.html (accessed October 15, 2007).
McKersie, B.D., Lepock, J.R., and Thompson, J.E. 1978. The effects of cotyledon senescence on the composition
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