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Packaging of Food Products

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Introduction

• Packaging: Is a process that is intended to preserve food against spoilage and contamination and extend the shelf life.

It provides the following benefits: containment (holding the product), Protection (quality, safety, freshness), information (graphics, labels), and utility of use or convenience. Important for dating indicators. It may be used as a promotion tool.

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Packaging materials for food include:• metal, • glass, • paper, • plastics, • wood crates, • cotton, • or burlap (jute).

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• Food may be packaged by two main ways: vacuum packaged, subject to controlled or modified

atmospheric packaging, Vacuum packaging: is a method of packaging that removes air

from the package prior to sealing. The intent is usually to remove oxygen from the container to extend the shelf life of foods and, with flexible package forms, to reduce the volume of the contents and package

or be aseptically packaged.

Manufacturers must adhere to FDA regulations regarding both the method and materials of packaging

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Types of Packaging Containers

• Packaging containers are classified as:1. primary, 2. secondary, 3. and tertiary.

A primary container is the bottle, can, drink box, and so forth that contains food.

It is a direct-food-contact surface, and therefore is subject to approval by the Food and Drug Administration (FDA), which tests for the possible migration of packaging materials into food.

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• secondary container: This offers additional food protection during

storage and distribution where errors, such as dropping or crushing cartons, may occur.

• and tertiary container Tertiary containers prevent the impact of falling

on the individual food container.

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Purposes of Packaging• The purposes or goals of packaging are numerous such as:

1. protecting raw or processed foods against spoilage and contamination by an array of external hazards.

2. Packaging serves as a barrier in controlling potentially damaging levels of light, oxygen, and water.

3. It facilitates ease of use,

4. offers adequate storage,

5. conveys information,

6. and provides evidence of possible product tampering by tamper-evident labels.

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7. Controlling absorption of O2 and water vapor.

8. Facilitating ease of using product contents, such as packaging that incorporates the components of a meal together in meal “kits”.

9. Communicating information regarding ingredients, nutrition facts, manufacturer name and address, weight, bar code information, and so forth via package labeling.

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Packaging Materials

• In choosing the appropriate packaging for their product, packers must consider many variables.

cost,product compatibility, Components and shelf life, flexibility of size, handling systems,

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closing speeds, processing reaction, impermeability, dent and tamper resistance, and consumer convenience and preference

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• Processors who use films for their product must select film material based on its “barrier” properties that prevent:

• oxygen, • water vapor, • or light from negatively affecting the food.

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As an example, the use of packaging material that prevents light-induced reactions will control the following points:

1. degradation of the chlorophyll pigment,2. bleaching or discoloration of vegetable and

red meats, 3. destruction of riboflavin in milk, 4. and oxidation of vitamin C.

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• The most common food packaging materials include:

1. metals,

2. glass,

3. paper,

4. And plastic.

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Metal

• Metals such as:1. steel 2. and aluminum are used in cans.

• A metal can forms a hermetic seal, which is a complete seal against gases and vapor entry or escape and it offers protection to the contents.

• Metal also is used for bottle closures and wraps.

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Steel has a noncorrosive coating of tin inside,

• Steel is manufactured into the traditional three-piece construction can, which includes:

1. a base, 2. cylinder, 3. and lid,

• and also a two-piece can, consisting of:1. a base and cylinder in one piece without a seam 2. and a lid.

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• In addition to steel cans, more than 25 billion beverage bottles crowns (closures with crimped edges) made of steel are used annually in the United States.

• New microwavable steel cans are available for packaging.

This is due to new developments in steel can technology.

A plastic end is attached to a steel can body, allowing microwave energy to pass through and heat the product.

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Aluminum is formed easily into cans with hermetic seals.

• It also is used in trays and for wraps such as aluminum foil, which provide an oxygen and light barrier.

• Has the following advantages: It is lighter in weight than steel and resists corrosion.

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Glass

• Glass is derived from metal oxides such as silicon dioxide.

• It is used in forming bottles or jars (which subsequently receive hermetic seals),

• And thus protects against water vapor or oxygen loss or gain.

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• The thickness of glass must be sufficient to prevent breakage from the following effects:

internal pressure, external impact, Or thermal stress.

Glass that is too thick has the following disadvantages:• Increases weight, • and thus freight costs, • and is subject to an increased of thermal stress.

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• Technological advances in glass packaging have led to improvements in:

strength and weight, as well as color and shape.

yet the see-through glass tends to denote “fresh” to the consumer.

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Paper

• Paper is derived from the wood and may contain additives such as:

o aluminum particle, o plastic coating, o Resins or waxes.

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These additives provide the following benefits:• rupture strength (strength against bursting or rupture), • wet strength (leak protection),• and grease resistance, • as well as barrier properties that assure:

freshness, protect the packaged food against vapor loss protect the packaged food against environmental

contaminants, and increase shelf life.

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• Varying thicknesses of paper may be used to achieve thicker and more rigid packaging:

thin one layer paper ( flexible), typically used in bags and wrappers. It may be bleached and used as butcher wrap or may remain unbleached and used in grocery bags.

thicker Paperboard (although still one layer) and more rigid.

Multilayers of paper, which is recognized as “cardboard.”

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• When packaging serves as a primary container for food, it is a food-contact surface and must be coated or treated accordingly.

For example, paper bags or wraps for bakery products may be laminated to improve:

burst or wet strength,grease and tear resistance, or prevent loss of moisture.

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• Paperboard may be formed to hold fluid milk. It may be formed into packages with foil linings and resealable plastic, to provide:

Convenienceprotection and extended shelf life.

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Plastic

• Plastic has the following applications:shrink, nonshrink, flexible, semirigid, and rigid, applications

And they varies in its degree of thickness.

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• Important properties of the many types of plastics that make them good choices for packaging material include the following:

1. Flexible and stretchable2. Lightweight3. Low-temperature formability4. Resistant to breakage, with high burst strength5. Strong heat sealability6. Versatile in its barrier properties to O2, moisture, and light.

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• Chemistry of plastic:

The building blocks of plastic are hydrocarbon such as ethane and methane,

which are derived from: natural gas and petroleum,

They form organic chemical compounds called monomers.

These are then chemically linked to form plastic molecular chains, or polymers.

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• Plastic has multiple functions as a packaging material, including use in:

bottles jars, closures, films, bags, tubs, and trays.

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• Plastic also may be used in combination with other packaging materials such as:

1. metal (for lining cans),

2. Paper (for moisture resistance),

3. and glass (reduces bottle breakage).

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• Among the thousands of types of plastics that are created, little number of polymers utilized in food packaging.

• Some of the more commonly used plastics for food products are:

1. Polyethylene (PE): • Is the most common, comprising 63% of total plastic

packaging• and the least expensive plastic.

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• It is a water-vapor (moisture) barrier and prevents dehydration and freezer burn.

Freezer burn is a condition that occurs when frozen food has been damaged by dehydration and oxidation, due to air reaching the food. It is generally induced by non-airtight packaging

• Use of Polyethylene may be recommended for less plasticizer migration into food.

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• An example of the polyethylene used in producing plastic, such as:

Plastic bags,

resealable bags,

and plastic storage containers.

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2. Polypropylene (PP):

• Has a higher melting point and greater tensile strength than polyethylene.

• It often is used as the inside layer of food packages that are subject to higher temperatures of sterilization.

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3. Polystyrene (PS): • Polystyrene is a versatile, inexpensive

packaging material

• represents 8% of total plastic packaging.

• its generic name is expandable polystyrene (EPS).

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has applications in:• disposable packaging and drinking cups. • is used in fast-food packaging, • egg cartons.

Approximately 30% less energy is required to form polystyrene cups than paperboard cups.

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4. Polyvinyl chloride (PVC):

• Comprises 6% of total plastic packaging.

• It barrier of air and moisture, preventing freezer burn,

• prevents the transfer of odor and keeps food fresh by controlling dehydration

• and is capable of withstanding high temperatures without melting.

• PVC has good “cling” properties.

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Other Packaging Materials

Cotton or burlap (jute) may be used for:grains, flour, legumes, and some vegetables, used primarily in transport.

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Laminates:• are multilayers of foil, paper, or plastics that

may be utilized selectively according to the specific food packaging need.

• In combination, the various laminates may provide more strength and barrier protection than the individual laminate material.

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Laminates have the following advantages:• provide barriers useful in controlling O2, • Controlling water vapor, • Controlling light transmission • and they provide good burst strength. • The laminates may resist flex cracking.

Wood may be used in the manufacture of crates that contain fresh fruits and vegetables.

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Controlling Packaging Atmosphere

• Reduced temperature remains as the primary means of food protection.

• However, controlling the known elements in the package environment, such as O2, CO2, water vapor, and ethylene concentration,

also may reduce spoilage and contamination (eg, enzymatic, biological),

thus extending shelf life (the time required for a food to become unacceptable from a sensory, nutritional, or safety perspective)

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• Providing control atmosphere in packaging is needed by fruits and vegetables.

• They continue to breathe and require oxygen after harvesting and processing,

Thus the package must contain oxygen.

o Yet it needs to be controlled, as too high a level causes oxidation and spoilage and too low a level leads to anaerobic spoilage.

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• The most important manner of controlling packaging atmosphere:

Vacuum Packaging

• Vacuum packaging modifies the atmosphere surrounding the food by removing oxygen, and it extends shelf life.

• With the removal of oxygen, vacuum packaging controls rancidity that occurs with the oxidation of fatty acids.

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Vacuum-packaging machines are available for various capacity: • small-, • medium-,• or large-scale production capacity

And may be used to successfully package a variety of food sizes and forms such as:

• small cheese blocks, • large cuts of meat.

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• The procedure used for vacuum packaging is:

1. to place the food in a flexible film or barrier pouch,

2. and put it inside a vacuum-packaging chamber, where oxygen is removed.

3. This creates a skintight package wall and protects against the entry or escape of gases such as air and CO2, or water vapor.

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Vacuum packaging offers the following advantages:

• assures inhibition of microbial growth that would alter microbial and organoleptic properties such as appearance and odor.

• Water loss and freezer burn also are inhibited with this packaging method.

• The transparent, vacuum-packaging film allows product visibility from all sides.