Postharvest Lifelines A Guide to Making Perishables Last Longer Everyone knows that humans have basic needs to fill in order to stay alive. Water, oxygen, food, shelter, etc. The same is true for fruits and vegetables. After produce is harvested, it carries on what is known as postharvest life (also called "shelf life" or "home life.”) That means that if conditions are right, produce continues to look and stay healthy for a specific number of days or weeks and be suitable for sale and consumption. Peaches, for example, have a postharvest life of 14- 28 days. If they are handled properly after harvest, stored in an environment with appropriate relative humidity levels and temperature, and protected from harmful ethylene gas exposure, peaches will remain saleable and edible for up to four weeks. However, if just one of those four basic needs (or controls) is not met to the fullest, the postharvest life will be d control factor might mean the peach will last only1 or 2 days. That's quite a loss. Be sure you're meeting the postharvest needs of your perishables. Find out the optimum storage conditions (relative humidity level, temperature, ethylene sensitivity) of each particular fruit or vegetable. With knowledge, planning and postharvest storage equipment you can meet ramatically reduced. Cutting off more than one all of the four basic needs of a perishable product. Peaches are highly sensitive to ethylene gas and must be stored in a room with 90-95% relative humidity. (RH reading before addition of product) the postharvest life exponentially. A 35% decrease in optimum temperature yields a 50% decrease in shelf life.* So by dropping the storage o temperature of a peach by just 10 - you automatically cut its potential shelf life down to 14 days. Reducing the effectiveness of any one of the four control areas, decreases Postharvet Days 28 21 14 7 904-223-1008 www.airocide.com Optimizing Produce Shelf Life & Home Life *From the University of California; Davis, Calif. A peach will only last about 14 o days stored at 43.2F. (35% warmer than optimum temp. of o 32F for peaches. ) A peach will last 28 days with all four controls at optimum levels. A peach may only last 7 days without ethylene removal (in addition to lack of temperature control.) A peach's expected life is 3-4 days without added humidity (in addition to lack of temp. and ethylene control.) The peach's life can be cut to 1-2 days if improperly handled (in addition to lack of temp., humidity and ethylene control.)
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Postharvest Guide Booklet-Akida · Photosynthesis, the main function of plants, is called stomata. Unfortunately for the plant, evaporation driven in nature not only by the light
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Postharvest LifelinesA Guide to Making Perishables Last Longer
Everyone knows that humans have
basic needs to fill in order to stay
alive. Water, oxygen, food, shelter,
etc. The same is true for fruits and
vegetables.
After produce is harvested, it
carries on what is known as postharvest life (also called
"shelf life" or "home life.”) That means that if conditions
are right, produce continues to look and stay healthy for a
specific number of days or weeks and be suitable for sale
and consumption.
Peaches, for example, have a postharvest life of 14-
28 days. If they are handled properly after harvest, stored
in an environment with appropriate relative humidity
levels and temperature, and protected from harmful
ethylene gas exposure, peaches will remain saleable and
edible for up to four weeks.
However, if just one of those four basic needs (or
controls) is not met to the fullest, the postharvest life will
be d
control factor might mean the peach will last only1 or 2
days. That's quite a loss.
Be sure you're meeting the postharvest needs of your
perishables. Find out the optimum storage conditions
of each particular fruit or vegetable. With knowledge,
planning and postharvest storage equipment you can meet
ramatically reduced. Cutting off more than one all of the four basic needs of a perishable product.
Peaches are highly sensitive to ethylene gas and must be stored in a room with 90-95% relative humidity. (RH reading before addition of product)
the postharvest life exponentially.
A 35% decrease in optimum temperature yields a 50% decrease in shelf life.* So by dropping the storage
otemperature of a peach by just 10 - you automatically cut its potential shelf life down to 14 days.
Reducing the effectiveness of any one of the four control areas, decreases
Po
sth
arv
et D
ay
s
28
21
14
7
904-223-1008
www.airocide.com
Optimizing Produce Shelf Life & Home Life
*From the University of California; Davis, Calif.
A peach will only last about 14 odays stored at 43.2F. (35%
warmer than optimum temp. of o32F for peaches. )
A peach will last 28 days with all four controls at
optimum levels.A peach may only last 7 days without ethylene removal (in addition to lack
of temperature control.)
A peach's expected life is 3-4 days without added humidity (in
addition to lack of temp. and ethylene control.)
The peach's life can be cut to 1-2 days if improperly handled (in addition to lack of
temp., humidity and ethylene control.)
Temperature Humidity
Ethylene Gas
Handling
By lowering the temperature at which As a function of photosynthesis, which happens
produce is stored, you can actually fool the even after harvest, plants pull water through
plant into slowing down its aging process and lasting their bodies and to their surface through tiny openings
longer. Photosynthesis, the main function of plants, is called stomata. Unfortunately for the plant, evaporation
driven in nature not only by the light of the sun but also takes place wherever water comes in contact with the air
by heat. Cooler temperatures mean a slower rate of and the plant continually loses moisture. In a refrigerated
photosynthesis. The rate of evaporation from the plant's storage area, rapidly moving air accelerates the process.
surface actually doubles for every temperature rise of After harvest produce can no longer pull water from o o the ground and replenish its moisture content, so keeping about 10 C (18 F).*
the evaporation rate down is crucial. Higher relative Lower temperatures also suppress what is known as
humidity around the surface of the plant slows down the the climacteric phase in many fruits. Climacteric fruits
evaporation rate and lets the plant keep its moisture.experience periods of increased respiration and quick
ripening. The faster fruit ripens, the shorter its shelf life.
Cooler temperatures help to slow down this process just
enough to keep the fruit around for its optimum
postharvest life.
Ethylene gas (C H ) is a ripening agent 2 4
produced by all plant tissue. When fruits and
vegetables are growing in the ground ethylene plays an
important role in the life cycle. Ethylene helps fruit
Handling may seem to be the most basic of the become colorful and tasty - attractive to animals so that
four controls, however, it is quite important. they eat the fruit and spread its seeds.
Mechanical injury to produce, including cuts, After harvest, however, ethylene can be a plant's
compressions, impacts and vibration rubbing will all lead worst enemy. As little as 1 part per million (ppm) of
to wounding and bruising the produce. A piece or even an ethylene in the air speeds up plant ripening and makes
entire box of produce can be ruined with just one drop. At produce more vulnerable to diseases. Since plants
the very least its marketable life is drastically reduced.produce ethylene even after they are harvested, and are
Careful attention must be paid to packing and exposed to external sources of ethylene, confined storage
transporting methods. Below are just a few guidelines to areas are full of deadly ethylene gas. Without ethylene
follow:removal, the optimum postharvest life of a fruit or
vegetable can be cut to just a few days.
The Four Controls
*Biology of Plants; Raven, Evert & Eichhorn;1986
From the Journal of Chemical Education; April, 1992
External Sources of Ethylene Gas
Automobile Exhaust
400 ppm
Coal Gas10 ppm
Cigarette Smoke4 ppm
Employ supervision and Provide some gaps for management of loading and ventilation to avoid unloading overheating
Use ramped loading bays Use containers strong enough for multiple stackingProvide shelter from sun and
rain at loading and unloading Select experienced drivers areas when transporting
Use trolleys, conveyors and Distribute weight evenlyfork-lifts to reduce the amount of manual handling
Pack boxes tightly to make best use of space
Don't overfill boxes and crates
6 AM0
10
20
30
6 AM MIDNIGHTNOON
Transpiration
WaterUptake
Rela
tive R
ate
(Gra
ms
per
2 h
ours
)
Measurements of water
movement in trees shows that
a rise in water uptake follows
a rise in transpiration. After
harvest, as a plant continues
to transpire, it is subjected to
constant dehydration.
Transpiration Rate
From Biology of Plants; Raven, Evert & Eichhorn;1986
www.airocide.com
904-223-1008
Produce Storage GuideOptimum Environmental Conditionsfor Maintaining Freshness
Moisture Loss Sensitivity Most products need to be transported and stored at a high relative humidity. However ,some products are more
susceptible to moisture loss than others. Relative humidity during transit and storage must be maintained as much as possible.
Ethylene Producers Ethylene Sensitive
apples bananas, unripeapricots Belgian endiveavocados broccolibananas, ripening Brussels sproutscantaloupes cabbagecherimoya carrotsfigs cauliflowerhuavas chard honeydew melons cucumberskiwifruit, ripe eggplantmamey sapote green beansmangoes kiwifruit, unripemangosteen leafy greensnectarines lettucepapayas okra passion fruit parsleypeaches peaspears pepperspersimmons spinachplantains squashplums sweet potatoesprunes watercressquinces watermelonrambutan yamstomatoes
Ethylene Sensitivity Never transport or store fruits and vegetables that produce a lot of ethylene with products that are sensitive to it. Ethylene can cause premature ripening of some products and will ruin others.
atemoya jackfruit soursopavocados langsat sugar apple
Produce Misting For many types of produce, misting is not only necessary for maintaining moisture content while on display, but can also help sell product by giving it a healthy glisten. Some fruits and vegetables, though, can be harmed by too much moisture sprayed on them. Use the guide below to be sure not to mist produce that is non-mistable.
Respiration RatesPre-cooling is particularly important for products which produce a lot of heat. The following are examples of products which have high respiration rates.