Fruit & Vegetable Magazine

Features Fruit Production
New method to keep fruit, vegetables fresh

October 23, 2009  By Marg Land

October 23, 2009 —  A Georgia State University
professor has developed an innovative new way to keep produce and flowers fresh
for longer periods of time.

October 23, 2009 — Did you
know that millions of tons of fruits and vegetables in the United States end up
in the trash can before being eaten, according to the U.S. Department of

A Georgia State University
professor has developed an innovative new way to keep produce and flowers fresh
for longer periods of time. Microbiologist George Pierce’s method uses a
naturally occurring microorganism – no larger than the width of a human hair –
to induce enzymes that extend the ripening time of fruits and vegetables, and
keeps the blooms of flowers fresh. The process does not involve genetic
engineering or pathogens, but involves microorganisms known to be associated
with plants, and are considered to be helpful and beneficial to them.

“These beneficial soil
microorganisms serve essentially the same function as eating yoghurt as a
pro-biotic to have beneficial organisms living in the gastrointestinal system,”
Pierce said.

The process works by
manipulating the organism’s diet so that it will over express certain enzymes
and activities that work in the ripening process and keeping the flower blooms
fresh. Pierce analogizes this to using diet and exercise to improve the
performance of an athlete.

“We change the diet of the
organism, and we can change its performance,” Pierce said. “It’s no different
than taking a good athlete and putting them on a diet and exercise regime, and
turning him or her into a world-class athlete.”

In a very simple sense,
climacteric plants – such as apples, bananas, peaches and tomatoes ­­­– respond
to climactic change, and when they do, they produce increased levels of signal
compounds like ethylene. For fruit such as peaches, ethylene causes the peach
to ripen, increases aroma chemicals, but unfortunately, makes the peach very

“If you’ve seen ripe
peaches, they will simply fall apart,” Pierce said. “It will lose 90 per cent
of its ability to resist pressure, which means that if a peach responds
normally to ethylene, it is subject to bruising when you ship it.”

The enzymes produced from
Pierce’s new method reduce the response to signal compounds so that it takes a
longer period of time for fruits to ripen, doubling the time it takes for

The catalyst in this
process can be distributed through various formulations and configurations.
These include being incorporated into shipping boxes, packing materials or used
to treat the air of shipping containers. It could be used either with
individual fruits or vegetables or for larger, bulk quantities.

This new process could
have a big impact on preventing waste, improving the consumption of healthy
fruits and vegetables, allowing companies to ship produce longer distances.

“Who hasn’t bought fruit
or vegetables and then thrown them away?” Pierce said. “Most people will buy
more, and consume more, if they know that they could have a better quality of
produce for longer.”

The method also will allow
for the storage of fruits, vegetables and flowers at room temperatures rather
than refrigeration, thus helping to save energy, Pierce said.

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