PACKAGING REQUIREMENTS FOR FRESH FRUITS AND VEGETABLES

Introduction				portion of synthetic fibers for additional
				strength, sizing (starch), and other
Packaging fresh fruits and vegetables is one				materials to give it wet strength and
of the more important steps in the long and				printability. Most fiberboard contains some
complicated journey from grower to consumer.				recycled fibers. Minimum amounts of recycled
Bags, crates, hampers, baskets, cartons, bulk				materials may be specified by law and the
bins, and palletized containers are				percentage is expected to increase in the
convenient containers for handling,				future. Tests have shown that cartons of
transporting, and marketing fresh produce.				fully recycled pulp have about 75 percent of
More than 1,500 different types of packages				the stacking strength of virgin fiber
are used for produce in the U.S. and the				containers. The use of recycled fibers will
number continues to increase as the industry				inevitably lead to the use of thicker walled
introduces new packaging materials and				containers.
concepts.
				Double-faced corrugated fiberboard is the
Although the industry generally agrees that				predominant form used for produce containers.
container standardization is one way to				It is produced by sandwiching a layer of
reduce cost, the trend in recent years has				corrugated paperboard between an inner and
moved toward a wider range of package sizes				outer liner (facing) of paper-board. The
to accommodate the diverse needs of				inner and outer liner may be identical, or
wholesalers, consumers, food service buyers,				the outer layer may be preprinted or coated
and processing operations.				to better accept printing. The inner layer
				may be given a special coating to resist
Packing and packaging materials contribute a				moisture. Heavy-duty shipping containers,
significant cost to the produce industry;				such as corrugated bulk bins that are
therefore it is important that packers,				required to have high stacking strength, may
shippers, buyers, and consumers have a clear				have double- or even triple-wall
understanding of the wide range of packaging				construction. Corrugated fiberboard
options available. This fact sheet describes				manufacturers print box certificates on the
some of the many types of packaging,				bottom of containers to certify certain
including their functions, uses, and				strength characteristics and limitations.
limitations. Also included is a listing, by				There are two types of certification.
commodity, of the common produce containers
standard to the industry.				The first certifies the minimum combined
				weight of both the inner and outer facings
The Function of Packaging or Why package				and that the corrugated fiberboard material
Produce?				is of a minimum bursting strength. The second
				certifies minimum edge crush test (ETC)
A significant percentage of produce buyer and				strength. Edge crush strength is a much
consumer complaints may be traced to				better predictor of stacking strength than is
container failure because of poor design or				bursting strength. For this reason, users of
inappropriate selection and use. A properly				corrugated fiberboard containers should
designed produce container should contain,				insist on ECT certification to compare the
protect, and identify the produce, satisfying				stackability of various containers. Both
everyone from grower to consumer.				certificates give a maximum size limit for
				the container (sum of length, width, and
PACKAGING POINTS				height) and the maximum gross weight of the
				contents.
Recyclability/Biodegradability.
				Both cold temperatures and high humidities
A growing number of U.S. markets and many				reduce the strength of fiberboard containers.
export markets have waste disposal				Unless the container is specially treated,
restrictions for packaging materials. In the				moisture absorbed from the surrounding air
near future, almost all produce packaging				and the contents can reduce the strength of
will be recyclable or biodegradable, or both.				the container by as much as 75 percent. New
Many of the largest buyers of fresh produce				anti-moisture coatings (both wax and plastic)
are also those most concerned about				are now available to substantially reduce the
environmental issues.				effects of moisture.

Variety.				Waxed fiberboard cartons (the wax is about 20
				percent of fiber weight) are used for many
The trend is toward greater use of bulk				produce items that must be either hydrocooled
packages for processors and wholesale buyers				or iced. The main objection to wax cartons is
and smaller packages for consumers. There are				disposal after use- wax cartons cannot be
now more than 1,500 different sizes and				recycled and are increasingly being refused
styles of produce packages.				at landfills. Several states and
				municipalities have recently taxed wax
Sales Appeal.High quality graphics are				cartons or have instituted rigid back haul
increasingly being used to boost sales				regulations. Industry sources suggest that
appeal. Multi-color printing, distinctive				wax cartons will eventually be replaced by
lettering, and logos are now common.				plastic or, more likely, the use of ice and
				hydrocooling will be replaced by highly
Shelf Life.				controlled forced-air cooling and rigid
				temperature and humidity maintenance on many
Modern produce packaging can be custom				commodities.
engineered for each commodity to extend shelf
life and reduce waste.				In many applications for corrugated
				fiberboard containers, the stacking strength
Containment				of the container is a minor consideration.
				For example, canned goods carry the majority
The container must enclose the produce in				of their own weight when stacked. Fresh
convenient units for handling and				produce usually cannot carry much of the
distribution. The produce should fit well				vertical load without some damage. Therefore,
inside the container, with little wasted				one of the primarily desired characteristics
space. Small produce items that are spherical				of corrugated fiberboard containers is
or oblong (such as potatoes, onions, and				stacking strength to protect the produce from
apples) may be packaged efficiently utilizing				crushing. Because of their geometry, most of
a variety of different package shapes and				the stacking strength of corrugated
sizes. However, many produce items such as				containers is carried by the corners. For
asparagus, berries, or soft fruit may require				this reason, hand holes and ventilation slots
containers specially designed for that item.				should never be positioned near the corners
packages of produce commonly handled by hand				of produce containers and be limited to no
are usually limited to 50 pounds. Bulk				more than 5 to 7 percent of the side area.
packages moved by fork lifts may weigh as
much as 1,200 pounds.				Interlocking the packages (cross stacking) is
				universally practiced to stabilize pallets.
Protection				Cross stacking places the corner of one
				produce package at the middle of the one
The package must protect the produce from				below it, thus reducing its stacking
mechanical damage and poor environmental				strength. To reduce the possibility of
conditions during handling and distribution.				collapse, the first several layers of each
To produce buyers, torn, dented, or collapsed				pallet should be column stacked (one package
produce packages usually indicate lack of				directly above the other). The upper layers
care in handling the contents. Produce				of packages may be cross stacked as usual
containers must be sturdy enough to resist				with very little loss of pallet stability.
damage during packaging, storage, and
transportation to market.				There are numerous styles of corrugated
				fiberboard containers. The two most used in
Because almost all produce packages are				the produce industry are the one piece,
palletized, produce containers should have				regular slotted container (RSC) and the two
sufficient stacking strength to resist				piece, full telescoping container (FTC). The
crushing in a low temperature, high humidity				RSC is the most popular because it is simple
environment. Although the cost of packaging				and economical.
materials has escalated sharply in recent
years, poor quality, lightweight containers				However, the RSC has relatively low stacking
that are easily damaged by handling or				strength and therefore must be used with
moisture are no longer tolerated by packers				produce, such as potatoes, that can carry
or buyers.				some of the stacking load. The FTC, actually
				one container inside another, is used when
Produce destined for export markets requires				greater stack- ing strength and resistance to
that containers to be extra sturdy.				bulging is required. A third type of
Air-freighted produce may require special				container is the Bliss box, which is -
packing, package sizes, and insulation.				constructed from three separate pieces of
Marketers who export fresh produce should				corrugated fiberboard. The Bliss box was
consult with freight companies about any				developed to be used when maximum stacking
special packaging requirements. Additionally,				strength is required. The bottoms and tops of
the USDA and various state export agencies				all three types of containers may be closed
may be able to provide specific packaging				by glue, staples, or interlocking slots.
information.
				Almost all corrugated fiberboard containers
Damage resulting from poor environmental				are shipped to the packer flat and assembled
control during handling and transit is one of				at the packing house. To conserve space,
the leading causes of rejected produce and				assembly is usually performed just before
low buyer and consumer satisfaction. Each				use. Assembly may be by hand, machine, or a
fresh fruit and vegetable commodity has its				combination of both. Ease of assembly should
own requirements for temperature, humidity,				be carefully investigated when considering a
and environmental gas composition. Produce				particular style of package.
containers should be produce friendly -
helping to maintain an optimum environment				In recent years, large double-wall or even
for the longest shelf life. This may include				triple- wall corrugated fiberboard containers
special materials to slow the loss of water				have increasingly been used as one-way pallet
from the produce, insulation materials to				bins to ship bulk produce to processors and
keep out the heat, or engineered plastic				retailers. Cabbage, melons, potatoes,
liners that maintain a favorable mix of				pumpkins, and citrus have all been shipped
oxygen and carbon dioxide.				successfully in these containers. The
				container cost per pound of produce is as
Identification				little as one fourth of traditional size
				containers. Some bulk containers may be
The package must identify and provide useful				collapsed and re-used.
information about the produce. It is
customary (and may be required in some cases)				For many years, labels were printed on heavy
to provide information such as the produce				paper and glued or stapled to the produce
name, brand, size, grade, variety, net				package. The high cost of materials and labor
weight, count, grower, shipper, and country				has all but eliminated this practice. The
of origin. It is also becoming more common to				ability to print the brand, size, and grade
find included on the package, nutritional				information directly on the container is one
information, recipes, and other useful				of the greatest benefits of corrugated
information directed specifically at the				fiberboard containers. There are basically
consumer. In consumer marketing, pack- age				two methods used to print corrugated
appearance has also become an important part				fiberboard containers:
of point of sale displays.
				Post Printed. When the liner is printed after
Universal Product Codes (UPC or bar codes)				the corrugated fiberboard has been formed,
may be included as part of the labeling. The				the process is known as post printing.
UPCs used in the food industry consist of a
ten-digit machine readable code. The first				Post printing is the most widely used
five digits are a number assigned to the				printing method for corrugated fiberboard
specific producer (packer or shipper) and the				containers because it is economical and may
second five digits represent specific product				be used for small press runs. However,
information such as type of produce and size				postprinting produces graphics with less
of package. Although no price information is				detail and is usually limited to one or two
included, UPCs are used more and more by				colors.
packers, shippers, buyers, and Example of a
UPC retailers as a fast and convenient method				Preprinted. High quality, full-color graphics
of inventory control and cost accounting.				may be obtained by preprinting the linerboard
Efficient use of UPCs requires coordination				before it is attached to the corrugated
with everyone who handles the package.				paperboard. Whereas the cost is about 15
				percent more than standard two color
Types of Packaging Materials				containers, the eye catching quality of the
				graphics makes it very useful for many
Wood				situations. The visual quality of the package
				influences the perception of the product
Pallets literally form the base on which most				because the buyer's first impression is of
fresh produce is delivered to the consumer.				the outside of the package. Produce managers
Pallets were first used during World War II				especially like high quality graphics that
as an efficient way to move goods. The				they can use in super market floor displays.
produce industry uses approximately 190 of
the 700 million pallets produced per year in				Preprinted cartons are usually reserved for
the U.S.. About 40 percent of these are				the introduction of new products or new
single-use pallets. Because many are of a				brands. Market research has shown that
non-standard size, the pallets are built as				exporters may benefit from sophisticated
inexpensively as possible and discarded after				graphics. The increased cost usually does not
a single use. Although standardization				justify use for mature products in a stable
efforts have been slowly under way for many				market, but this may change as the cost of
years, the efforts have been accelerated by				these containers becomes more competitive.
pressure from environmental groups, in
addition to the rising cost of pallets and				Pulp Containers. Containers made from
landfill tipping fees.				recycled paper pulp and a starch binder are
				mainly used for small consumer packages of
Over the years, the 40-inch wide, by 48-inch				fresh produce.
long pallet has evolved as the unofficial
standard size. Standardization encourages				Pulp containers are available in a large
re-use, which has many benefits. Besides				variety of shapes and sizes and are
reducing cost because they may be used many				relatively inexpensive in standard sizes.
times, most pallet racks and automated pallet				Pulp containers can absorb surface moisture
handling equipment are designed for				from the product, which is a benefit for
standard-size pallets. Standard size pallets				small fruit and berries that are easily
make efficient use of truck and van space and				harmed by water. Pulp containers are also
can accommodate heavier loads and more stress				biodegradable, made from recycled materials,
than lighter single-use pallets.				and recyclable.

Additionally, the use of a single pallet size				Paper and Mesh Bags. Consumer packs of
could substantially reduce pallet inventory				potatoes and onions are about the only
and warehousing costs along with pallet				produce items now packed in paper bags. The
repair and disposal costs. The adoption of a				more sturdy mesh bag has much wider use. In
pallet standard throughout the produce				addition to potatoes and onions, cabbage,
industry would also aid efforts toward				turnips, citrus, and some specialty items are
standardization of produce containers.				packed in mesh bags. Sweet corn may still be
				packaged in mesh bags in some markets. In
In the early 1950s, an alternative to the				addition to its low cost, mesh has the
pallet was introduced. It is a pallet-size				advantage of uninhibited air flow. Good
sheet (slipsheet) of corrugated fiberboard or				ventilation is particularly beneficial to
plastic (or a combination of these materials)				onions. Supermarket produce managers like
with a narrow lip along one or more sides.				small mesh bags because they make attractive
packages of produce are stacked directly on				displays that stimulate purchases.
this sheet as if it were a pallet. Once the
packages are in place, they are moved by a				However, bags of any type have several
specially equipped fork lift equipped with a				serious disadvantages. Large bags do not
thin metal sheet instead of forks.				palletize well and small bags do not
				efficiently fill the space inside corrugated
Slipsheets are considerably less expensive				fiberboard containers. Bags do not offer
than pallets to buy, store, and maintain;				protection from rough handling. Mesh bags
they may be re-used many times; and they				provide little protection from light or
reduce the tare weight of the load. However,				contaminants. In addition, produce packed in
they require the use of a special fork-lift				bags is correctly perceived by the consumer
attachment at each handling point from packer				to be less than the best grade. Few consumers
to retailer.				are willing to pay premium price for bagged
				produce.
Depending on the size of produce package, a
single pallet may carry from 20 to over 100				Plastic Bags. Plastic bags (polyethylene
individual packages. Because these packages				film) are the predominant material for fruit
are often loosely stacked to allow for air				and vegetable consumer packaging. Besides the
circulation, or are bulging and difficult to				very low material costs, automated bagging
stack evenly, they must be secured (unitized)				machines further reduce packing costs. Film
to prevent shifting during handling and				bags are clear, allowing for easy inspection
transit. Although widely used, plastic straps				of the contents, and readily accept high
and tapes may not have completely				quality graphics. Plastic films are available
satisfactory results. Plastic or paper corner				in a wide range of thicknesses and grades and
tabs should always be used to prevent the				may be engineered to control the
straps from crushing the corners of packages.				environmental gases inside the bag. The film
				material "breathes" at a rate necessary to
Plastic stretch film is also widely used to				maintain the correct mix of oxygen, carbon
secure produce packages. A good film must				dioxide, and water vapor inside the bag.
stretch, retain its elasticity, and cling to				Since each produce item has its own unique
the packages. Plastic film may conform easily				requirement for environmental gases, modified
to various size loads. It helps protect the				atmosphere packaging material must be
packages from loss of moisture, makes the				specially engineered for each item. Research
pallet more secure against pilferage, and can				has shown that the shelf life of fresh
be applied using partial automation. However,				produce is extended considerably by this
plastic film severely restricts proper				packaging. The explosive growth of precut
ventilation. A common alternative to stretch				produce is due in part to the availability of
film is plastic netting, which is much better				modified atmosphere packaging.
for stabilizing some pallet loads, such as
those that require forced-air cooling. Used				In addition to engineered plastic films,
stretch film and plastic netting may be				various patches and valves have been
difficult to properly handle and recycle.				developed that affix to low-cost ordinary
				plastic film bags. These devices respond to
A very low-cost and almost fully automated				temperature and control the mix of
method of pallet stabilization is the				environmental gases.
application of a small amount of special glue
to the top of each package. As the packages				Shrink Wrap. One of the newest trends in
are stacked, the glue secures all cartons				produce packaging is the shrink wrapping of
together. This glue has a low tensile				individual produce items. Shrink wrapping has
strength so cartons may be easily separated				been used successfully to package potatoes,
or repositioned, but a high shear strength so				sweetpotatoes, apples, onions, sweet corn,
they will not slide. The glue does not				cucumbers and a variety of tropical fruit.
present disposal or recycling problems.				Shrink wrapping with an engineered plastic
				wrap can reduce shrinkage, protect the
Pallet Bins. Substantial wooden pallet bins				produce from disease, reduce mechanical
of milled lumber or.plywood are primarily				damage and provide a good surface for
used to move produce from the field or				stick-on labels.
orchard to the packing house. Depending on
the application, capacities may range from 12				Rigid Plastic Packages. packages with a top
to more than 50 bushels. Although the height				and bottom that are heat formed from one or
may vary, the length and width is generally				two pieces of plastic are known as
the same as a standard pallet (48 inches by				clamshells. Clamshells are gaining in
40 inches). More efficient double-wide pallet				popularity because they are inexpensive,
bins (48 inches by 80 inches) are becoming				versatile, provide excellent protection to
more common in some produce operations.				the produce, and present a very pleasing
				consumer package. Clamshells are most often
Most pallet bins are locally made; therefore				used with consumer packs of high value
it is very important that they be consistent				produce items like small fruit, berries,
from lot to lot in materials, construction,				mushrooms, etc., or items that are easily
and especially size. For example, small				damaged by crushing.
differences in overall dimensions Pallet bin
can add up to big problems when several				Clamshells are used extensively with precut
hundred are stacked together for cooling,				produce and prepared salads. Molded
ventilation, or storage. It is also important				polystyrene and corrugated polystyrene
that stress points be adequately reinforced.				containers have been test marketed as a
The average life of a hardwood pallet bin				substitute for waxed corrugated fiberboard.
that is stored outside is approximately five				At present they are not generally cost
years. When properly protected from the				competitive, but as environmental pressures
weather, pallets bins may have a useful life				grow, they may be more common. Heavy-molded
of 10 years or more.				polystyrene pallet bins have been adopted by
				a number of growers as a substitute for
Uniform voluntary standards for wood pallets				wooden pallet bins. Although at present their
and other wood containers are administered by				cost is over double that of wooden bins, they
the National Wooden Pallet and Container				have a longer service life, are easier to
Association, Washington, DC. Additionally,				clean, are recyclable, do not decay when wet,
the American Society of Agricultural				do not harbor disease, and may be nested and
Engineers, St. Joseph, Michigan, publishes				made collapsible.
standards for agricultural pallet bins (ASAE
S337.1).				As environmental pressures continue to grow,
				the disposal and recyclability of packaging
Wire-Bound Crates. Although alternatives are				material of all kinds will become a very
available, wooden wire-bound crates are used				important issue. Common polyethylene may take
extensively for snap beans, sweet corn and				from 200 to 400 years to breakdown in a
several other commodities that require				landfill. The addition of 6 percent starch
hydrocooling. Wire-bound crates are sturdy,				will reduce the time to 20 years or less.
rigid and have very high stacking strength				packaging material companies are developing
that is essentially unaffected by water.				starch-based polyethylene substitutes that
Wire-bound crates come in many different				will break down in a landfill as fast as
sizes from half- bushel to pallet-bin size				ordinary paper.
and have a great deal of open space to
facilitate cooling and ventilation. Although				The move to biodegradable or recyclable
few are re-used, wire-bound crates may be				plastic packaging materials may be driven by
dissembled after use and shipped back to the				cost in the long term, but by legislation in
packer (flat). In some areas, used containers				the near term. Some authorities have proposed
may pose a significant disposal problem.				a total ban on plastics. In this case, the
Wirebound crates are not generally acceptable				supermarket of the early 21st century may
for consumer packaging because of the				resemble the grocery markets of the early
difficulty in affixing suitable labels.				20th century.

Wooden Crates and Lugs. Wooden crates, once				Standardization of Packaging
extensively used for apples, stone fruit, and
potatoes have been almost totally replaced by				Produce package standardization is
other types of containers. The relative				interpreted differently by different groups.
expense of the container, a greater concern				The wide variety of package sizes and
for tare weight, and advances in material				material combinations is a result of the
handling have reduced their use to a few				market responding to demands from many
specialty items, such as expensive tropical				different segments of the produce industry.
fruit. The 15-, 20-, and 25-pound wooden lugs				For example, many of the large-volume buyers
still used for bunch grapes and some				of fresh produce are those most concerned
specialty crops are being gradually replaced				with the environment. They demand less
with less costly alternatives.				packaging and the use of more recyclable and
				biodegradable materials, yet would also like
Wooden Baskets and Hampers. Wire-reinforced				to have many different sizes of packages for
wood veneer baskets and hampers of different				convenience. packers want to limit the
sizes were once used for a wide variety of				variety of packages they must carry in stock,
crops from strawberries to sweetpotatoes.				yet they have driven the trend toward
They are durable and may be nested for				preprinted, individualized containers.
efficient transport when empty. However,				Shippers and trucking companies want to
cost, disposal problems, and difficulty in				standardize sizes so the packages may be
efficient palletization have severely limited				better palletized and handled.
their use to mostly local grower markets
where they may be re-used many times.				Produce buyers are not a homogeneous group.
				Buyers for grocery chains have different
Corrugated Fiberboard				needs than buyers for food service. For
				grocery items normally sold in bulk,
Corrugated fiberboard (often mistakenly				processors want largest size packages that
called cardboard or pasteboard) is				they can handle efficiently - to minimize
manufactured in many different styles and				unpacking time and reduce the cost of
weights. Because of its relativity low cost				handling or disposing of the used containers.
and versatility, it is the dominant produce				Produce managers, on the other hand, want
container material and will probably remain				individualized, high quality graphics to
so in the near future. The strength and				entice retail buyers with in-store displays.
serviceability of corrugated fiberboard have
been improving in recent years.				Selecting the right container for fresh
				produce is seldom a matter of personal choice
Most corrugated fiberboard is made from three				for the packer. For each commodity, the
or more layers of paperboard manufactured by				market has unofficial, but nevertheless rigid
the kraft process. To be considered				standards for packaging; therefore it is very
paperboard, the paper must be thicker than				risky to use a nonstandard package. packaging
0.008 inches. The grades of paperboard are				technology, market acceptability, and
differentiated by their weight (in pounds per				disposal regulations are constantly changing.
1,000 square feet) and their thickness. Kraft				When choosing a package for fresh fruits and
paper made from unbleached pulp has a				vegetables, packers must consult the market,
characteristic brown color and is				and in some markets, standard packages may be
exceptionally strong. In addition to virgin				required by law.
wood fibers, Kraft paper may have some

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PACKAGING REQUIREMENTS FOR FRESH FRUITS AND VEGETABLES