INTRODUCTION TO FOOD PACKAGING 3114

1. INTRODUCTION TO FOOD PACKAGING3114 Steven C Seideman Extension Food Processing Specialist Cooperative Extension Service University of Arkansas

2. INTRODUCTION • This module is a brief overview of the area of food packaging. It is intended to give the reader an understanding of a broad, highly technical area. • Food packaging is an extremely broad area. Just go to a food store and look at all the types of packaging used for food items.

5. Functions of Food Packaging • Major role is preservation. • Aid the customer in the use of the product • Used to unitize or group product together • Used to communicate and educate the consumer

6. Packaging’s Role in Preservation • Protect the product from physical damage. (e.g. inject nitrogen in potato chip bags) • Protect the product from the environmental contamination from dirt, insects and air. • Limit the oxygen around the product. (This prevents the growth of bacteria and oxidation rancidity on food in vacuum packaged products) • Limit the loss of moisture in the product. (Prevents the surface dehydration of foods)

7. Aid The Customer in the Use of the Product • Food packaging should have features which make the product easier to use and add convenience. • This includes zip-lock / recloseable features, microwaveable products like popcorn, screw caps like on milk containers, dual ovenable trays, presliced cheeses etc.

8. Used to Unitize or Group Product Together • Most food products are shipped to stores in master cartons that contain a number of retail units. • Some retail foods are sold in individually packaged units such a soft drinks, small bags of chips and puddings for school children.

9. Used to Communicate and Educate the Consumer • It is the package that identifies the product to the consumer. • In addition to convincing customers to buy the product, the package must inform consumers about how to prepare or use the product, contents or amount of product contained, ingredients, nutritional content, and other pertinent information found on a label on the package.

10. The Cost of Packaging • The packaging industry, as a whole, is one of the largest industries in the United States and food packaging represents about half of the overall packaging industry. • Food packaging is not cheap. It does pay for itself in preventing food from spoilage. • The cost of packaging in many cases is greater than the cost of the raw ingredients used to make the food.

11. Requirements for Food Packaging • 1) Be non-toxic • 2) Protect against contamination and growth of microorganisms. • 3) Act as a barrier to moisture and oxygen. • 4) Filter out harmful UV light • 5) Provide resistance to physical damage • 6) Protect against the ingress of odors and environmental toxicants.

12. Requirements for Food Packaging • 7) Be tamper-resistant or tamper evident. • 8) Be easy to open • 9) Have dispensing and resealing features, if useful. • 10) Be readily disposable • 11) Meet size, shape and weight requirements. • 12) Have appearance, printability features

13. Requirements for Food Packaging • 12) Be low cost • 13) Be compatible with the food

14. Types of Food Containers • Food packaging can be divided into primary, secondary and tertiary types. • Let’s go through each one of these

15. Primary Containers • A primary container is one that comes in direct contact with the food, for example, a jar or a can. • It is the retail unit that you normally buy. • The packaging must be nontoxic, and compatible with the food and cause no odor, flavor or other foreign chemical reactions.

16. Secondary Containers • A secondary container is an outer box, case or wrapper that holds or unitizes several cans, jars, or other retail units together but does not contact the food directly. • It is often referred to as the master container. • It would not be possible to distribute products in glass jars, for example, without the corrugated secondary carton to protect against breakage. • The function of the secondary container is to protect the primary from physical damage during shipment and storage. • Corrugated fiberboard (cardboard) is the most commonly used to make secondary containers.

18. Tertiary Containers • Tertiary containers group several secondary cartons together into pallet loads or shipping units. • The objective of tertiary packaging is to aid in the automated handling of larger amounts of products. • Typically, a forklift or pallet jack is used to move and transport tertiary containers.

19. FOOD PACKAGING MATERIALS

20. Food Packaging Materials • There are relatively few materials used in food packaging ( metal, glass, paper and paperboard, plastics ) but within each of these categories, many types of packaging materials or combinations of materials are available. • For example, within the category of plastics, there are literally hundreds of types of films and laminates varying in moisture permeability, gas permeability, flexibility, bursting strength and so on.

21. Metal • Most cans are made of either steel or aluminum. • The majority of canned products are in steel. Up until a few years ago, most steel cans were coated with tin, hence the term “tin can”. The tin has been replaced with thin coatings of chromium and chromium oxide and some food compatible organic coatings. • The strength of the can is very important with the canning of fruits and vegetables since it must be able to withstand the pressure of retorting.

22. Metal • Steel cans are common for retorted fruits and vegetables because of the strength needed to withstand the external pressure exerted from retorting. • Aluminum is used primarily in the beverage industry (soft drinks and beer) since aluminum is structurally weak and the internal pressure from the carbon dioxide in the drink adds the necessary strength to the container.

23. Glass • Glass is chemically inert and an absolute barrier to the permeation of oxygen and water vapor. • The principle limitations to glass are its susceptibility to breakage, which may come from internal pressure, impact and thermal shock, its weight which increases shipping costs and the large amounts of energy required for forming into containers. • Glass is primarily formed from oxides of metals, with the most common being silicon dioxide which is common sand.

24. Glass • Many glass containers are being phased out of use to plastics. For example, milk and coffee used to be sold in glass jars but now come in plastic containers. • Breakage, liability issues, shipping weight are all reasons that glass is slowly being replaced by plastic.

25. Paper, Paperboard and Fiberboard • The principle differences between these three are thickness and ultimate use. • Papers are thin, flexible and used for bags and wraps. • Paperboard is thicker, more rigid and used to construct single-layer cartons. • Fiberboard is made by combining layers of strong papers and used to construct secondary shipping containers and is often referred to as “corrugated paperboard”.

26. Paper, Paperboard and Fiberboard • When used in primary containers, most paper products are treated, coated or laminated to improve their protective properties. • Paper from wood pulp and reprocessed waste paper is bleached and coated or impregnated with waxes, resins, lacquers, plastics and laminations of aluminum to improve its strength. • Other additives can be used to increase flexibility, tear resistance, burst strength, wet strength, grease resistance, sealability, appearance, printability and barrier properties

27. Plastics • The term “plastics” refers to a broad range of materials that have the common property of being composed of very large long-chain molecules and are made by connecting small repeating molecules called “monomers” together in a head-to-tail fashion, hence their name “polymers”. • Scientists came up with the concept of polymers from studying some natural occurring polymers such as starches, proteins and natural rubber.

28. Plastics • The are only about 20 polymers that are used in food packaging but when they are combined in a variety of ways, they give rise to hundreds of different plastic-containing structures. These polymers vary widely in strength, oxygen and moisture permeability, sealability etc

29. Cellulose Acetate Polyamide Polyesters Polyethylene Polypropylene Polystyrene Polyvinylidene chloride Polyvinyl chloride -Cellophane -Nylon -PET, Mylar -Saran-oxygen impermeable -PVC – meat overwrap Polymers used in Food Packaging

30. Copolymers • One can use a combination of the previous mentioned polymers to make what is called copolymers that combine the strengths of various polymers. • For example, we can combine ethylene with vinyl acetate, we get the plastic polyethylene-vinyl acetate copolymer known as ethylene-vinyl acetate

31. Laminates • One can fuse together various types of paper, plastics and aluminum foil to create a class of films called laminates. • The advantage of laminates is that they combine the advantages of certain materials to improve the resulting film. • Some commercial laminates may contain up to 8 layers.

32. Coextrusion • Coextrusion is the process whereby two or more molten plastics are layered upon each other in a flat manner and ultimately produces a multilayer film on cooling.

33. Edible Films • Edible films have been around for centuries. Sausage casings are one example. • Food materials can be protected from loss of volatiles or reaction from other food ingredients by being encapsulated in protective edible materials. • This can be accomplished by spraying a thin film of gelatin, gum arabic or other edible material onto a food product. • The coating of raisins with starches to prevent them from moistening the packaged breakfast cereal is one example.

34. Edible Films • Edible films are also used to coat fresh fruits and vegetables to reduce moisture loss and provide increased resistance to the growth of surface molds. • The most common and oldest edible film is wax. • A wide range of products such as apples are waxed for appearance and improved keeping quality

35. HOW DIFFERENT FOODS ARE PACKAGED

36. How Different Foods are Packaged • Since different foods spoil or deteriorate differently than others, there are certain ways that foods are packaged to give them the longest shelf life possible. • We will now go through some of the major categories of foods and discuss their packaging.

37. Meat Packaging • Red meats such as beef and pork have traditionally been overwrapped in a styrofoam tray with PVC film- oxygen permeability for red color. More recently, meats are being packaged in gas atmospheres such as a mixture of oxygen, carbon dioxide and nitrogen.

38. Red Meat Sausages Poultry Seafood PVC overwrap (Oxygen) Gas flushed in a tray Vacuum packaged Frozen turkeys In a O2 impermiable bag Gas atmosphere in a tray Frozen as precooked chicken Frozen Gas flushed Meat Packaging

43. Fruits and Vegetables • Canned- shelf stable • Jars- especially baby food • Frozen -in bags in a box • Netted fruits • Edible coated • Gas flushed plastic bags, especially salads

49. Cereals and Cereal Products • Oat Meal in paperboard • Most breakfast cereals in waxed or plastic bags inside a paperboard box. • Bread and bakery items are packaged in a plastic bag. • Crackers are packaged in waxed or plastic bags within a paperboard box.