Food Packaging
MAIN IDEA: Why is packaging such an important part of the food industry?
REQUIREMENTS FOR PACKAGING
Food packaging development started with humankind's earliest beginnings. Early
forms of packaging ranged from gourds to sea shells to animal skins. Later came
pottery, cloth and wooden containers. These packages were created to facilitate
transportation and trade.
Using modern technology, our society has created an overwhelming number of new
packages containing a multitude of food products. A modern food package has
many functions, but its main purpose is to physically protect the product during
transport. The package also acts as a barrier against potential spoilage agents,
which vary with the food product. For example, milk is sensitive to light, so a
package that provides a light barrier is necessary. Other foods like potato chips are
sensitive to air because the oxygen in the air causes rancidity. The bags containing
potato chips are made of materials with oxygen-barrier properties. Practically all
foods should be protected from filth, microorganisms, moisture and objectionable
odors. Consumers rely on the package to offer that protection.
Aside from protecting the food, the package serves as a vehicle through which the
manufacturer can communicate with the consumer. Nutritional information,
ingredients and often recipes are found on a food label. The package is also used as
a marketing tool designed to attract your attention at the store. This makes
printability an important property of a package.
TYPES OF CONTAINERS
Food packaging can be divided into three general types:
1. Primary
2. Secondary
3. Tertiary
Primary containers come in direct contact with the food. A secondary container is
an outer box or wrap that holds several primary containers together. Tertiary
containers group several secondary holders together into shipping units.
Many containers used in the food industry are form-fill-seal packaging. Containers
may be preformed at another site and then filled at the processing plant. Or
containers may be formed in the production line just ahead of the filling operation.
This is called form-fill-seal and it is one of the most efficient ways to package food.
To protect the food against exchange of gases and vapors, and contamination from
bacteria, yeasts, molds and dirt, containers are hermetically sealed. Hermetically
sealed containers are totally sealed against the escape or entry of air. The most
common hermetic containers are cans and glass bottles.
FOOD-PACKAGING MATERIALS AND FORMS
The food industry uses four basic packaging materials: metal, plant matter (paper
and wood), glass and plastic. A number of basic packaging materials are often
combined to give a suitable package. The fruit drink box is an example where
plastic, paper and metal are combined in a laminate to give an ideal package.
Another example of combination packaging is a peanut butter jar. The main
package containing the food (primary package) is made of glass or plastic, the lid is
made of plastic, and the label is made of paper.
Each basic packaging material has advantages and disadvantages. Metal is strong
and a good overall barrier, but heavy and prone to corrosion. Paper is economical
and has good printing properties; however, it is not strong and it absorbs water.
Glass is transparent, allowing the consumer to see the product, but it is breakable.
Plastics are versatile but often expensive.
For a product like milk, paper makes a good economical material. It also provides a
good printing surface. However, since paper absorbs water, it will gain moisture
from the milk, get weaker and fail; thereby exposing the milk to spoilage factors. It
may even break and waste the product. When a thin layer of a plastic called
polyethylene is used to line the inside of the milk carton, it serves as a barrier to
moisture and makes an economical, functional package.
After making a food product and placing it in the appropriate package, a number of
these individual packages must be placed in a large container for shipment. These
larger containers are called secondary packages. The paperboard box is a very
common secondary package. Plastics can also serve as secondary packages. The
milk case in which a number of milk cartons are delivered to the supermarket is a
good example.
Edible films are also used as packaging materials. By spraying gelatin, gum arabic,
starch, monoglycerides, proteins or other edible materials, a thin protective coating
can be formed around food particles. Sausage casings are an example of an edible
film. In other examples, raisins in breakfast cereals are sprayed to prevent them
from moistening the cereal in the box, and nuts are coated to protect them from
oxidative rancidity. An edible wax film is used to coat the surface of vegetables to
reduce moisture loss and provide increased resistance to the growth of molds. All
edible films for human consumption must be approved by the U.S. Food and Drug
Administration (FDA).
PACKAGE TESTING
Many tests measure the protective properties of packaging materials. Basically, the
tests can be divided into chemical and mechanical. Chemical tests are used to
determine if any of the packaging material, such as plastic, migrated into the food,
and to measure resistance to greases, acids, alkalies and other solvents.
Mechanical tests measure barrier properties, strength, heat-seal ability and clarity.
Actual tests consist of sending a few samples of the food-filled packages through
the complete processing, shipping, warehousing, and merchandising sequence. This
allows the packaging material to be subjected to all the normally occurring abuses.
These packages are recovered and analyzed to see how they withstood the
vibrations, humidities, temperature and handling processes. Sometimes similar
tests are performed in simulations.
PACKAGES WITH SPECIAL FEATURES
With the new foods being produced, packages frequently have some type of added
convenience feature. Often a package must withstand freezer temperatures as well
as boiling or the temperature of steam without bursting. The properties of polyester
and nylon films allow this type of dual use.
Microwave oven packaging presents another challenge to manufacturers. Microwave
oven packaging must meet all the standard requirements for packaging, it must be
transparent to microwaves, able to withstand high temperatures, and nontoxic
when heated.
Squeezable plastic bottles are used for all kinds of products. These bottles have the
high barrier properties of glass with less than one-fourth the weight and they do
not break.
Composite paper cartons can be sterilized and then aseptically filled with sterile
liquid products. This process is called aseptic packaging. This type of packaging
allows foods like milk and fruit juices to be packaged in inexpensive flexible
containers which require no refrigeration. From the outside of the container inward,
this packaging material is made from laminated layers of polyethylene, paper,
polyethylene, aluminum foil, polyethylene and a coating of ionomer resin.
Supplying food to the military has always created special problems. The packaging
must provide protection and yet simplify preparation and consumption under
adverse circumstances.
Consumers want packages that are easy to open and close. Yet, they want to be
assured that no one else has opened their food package before they did. Most food
packages now have some form of a tamper-resistant or tamper-evident feature.
These can be devices such as plastic bands that seal the closure or a membranous
film sealed across the removable lid of a container.
As for the ease of opening, the pull-tab beer and soda cans and the twist-off crown
caps on beverages are the best examples. Resealability is an obvious feature of
screw type lids and tab-closing boxes. Some specialty foods packaged in plastic
bags can be resealed with a "zipper," press adhesive or twist tie.
ENVIRONMENTAL CONSIDERATIONS
Packaging waste can adversely affect the environment. While recycling may be a
sound idea, the problem often lies in the feasibility of collection, separation and
purification of the consumer's disposed food packages. This mode of recycling is
called post-consumer recycling. While it offers a logistic challenge, recycling is
gaining in popularity, and the packaging industry is cooperating in that effort.
Aluminum cans are the most recycled container at this time. Plastic recycling is
increasing, yet most plastic is recycled during manufacturing of the containers -not as post-consumer recycling. For example, trimmings from plastic bottles are
reground and reprocessed into new ones.
The plastics industry facilitates consumer recycling by identifying the type of plastic
from which the container is made. A number from 1 to 7 is placed within the
recycling logo on the container's bottom. For example, 1 refers to PET
(Polyethylene Terephthalate), the plastic used for the large two-liter soft drink
bottles. Plastics have the advantage of being light. This helps to conserve fuel
during transport and also reduces the amount of package waste.
Environmental issues have gained importance because of regulatory requirements.
Increasingly, it is not possible to sell a new packaging material without covering all
the environmental issues. It is possible that if someone feels a package does not
meet environmental standards, the brand name could suffer.
Environmental regulations also play an important part in beverage packaging as
well. An important trend in beverage packaging is the use of nonreturnable bottles
as well as cans. The PET bottle is also used more and more in both returnable and
nonreturnable applications. With the increased use of plastic containers worldwide,
recycling and return concepts have become an absolute necessity.
INNOVATIONS IN PACKAGING
Packaging innovation is switching focus from cost to convenience. Innovation
means introducing something new or different. Consumers want convenience, and
food companies are developing packages to provide it. Globalization and continued
environmental pressures provide new challenges to the food packaging industry as
well.
Cost is no longer the main driver behind packaging innovations. Consumers want
convenience, whether it is the elderly consumer who needs to read the label on a
box of cookies or the working mother who does not have time to cook a fresh meal.
More households are small and the number of elderly consumers is increasing. This
means packaging should not only be easy to open, but you should also be able to
close it again so that food will keep longer.
Ready meals are catching on. This phenomenon has swept across the United States
and will become more important in the European market. Food processors see a
growing demand for convenience foods like kitchen-ready preparations of pasta
products, oven-ready preparations of pizza and related products.
Along with the desire for convenience, the popularity of microwavable food is
growing. For these foods, some packaging companies developed an expanded
polypropylene tray that is convenient to handle. These trays provide foods with
extended shelf-life, fresh product presentation and environmental savings. The
material can also be heated safely in the microwave, and the insulating feel of the
foam material allows the consumer to comfortably handle the package after
heating.
Consumer attitudes toward packaging have also changed. While consumers want
convenience, they also demand higher levels of package security. A similar conflict
arises with child-resistant packages which must be too difficult for children, but still
possible for infirm or elderly adults to open.
Processors recognize that foods must meet consumer quality standards and also
appeal to differing regional and national palates. For example, McDonald's
recognized that many consumers in India look on cows differently than in
Westernized countries. The company adjusted the menu to meet local needs. This
is happening in other areas as well. For example, although the Japanese have
developed a taste for beef products, they do not eat large portions; so the package
size is adjusted. In China where there is an abundant hog supply, the company is
beginning to take advantage of this situation to produce more sophisticated pork
products.