INTRODUCTION TO FOOD PACKAGING

Transcription

1 INTRODUCTION TO FOOD PACKAGING 3 RD WEEK Prepared by Assist. Prof. Dr. Fatih TÖRNÜK

2 Lecture Content 1. Introduction to packaging, history and definitions 2. Quality and shelf life of packaged foods 3. Food packaging materials 4. Paper, wood and glass packaging materials 5. Metal packages 6. Plastic packages 7. Modified atmosphere and vacuum packaging 8. Active and intelligent packaging 9. Packaging of meat and meat products 10. Packaging of milk and dairy products 11. Packaging of cereal and cereal products 2

3 Presentation Outline Introduction Definitions Functions of Food Packaging History of Food Packaging Required Qualifications of A Packaging Material Classification of Food Packagings Characteristic Properties of Food Packaging Materials 3

4 Introduction Food packaging can be considered as a combination of art, science and technology that is used in the transportation and selling of foods. The primary role of food packaging is to protect food products from the outside environment and from damage by abrasion, to contain the food, and to provide consumers information about ingredients and nutrition. The main requirement of food packaging is to maintain the safety, wholesomeness and quality of food. 4

5 Definitions Packaging can be defined as a method to protect and contain foods with the aim of minimizing the environmental impact until their consumption. With a wider definition; food packaging is enclosure of products, items or packages to perform one or more of the following functions: containment, protection, preservation, communication, utility and performance. If the device or container performs one or more of these functions, it is considered a package. 5

6 Functions of Food Packaging There are 7 main reasons why packaging was developed and is in use today: 1. Protective function 2. Containment function 3. Marketing function 4. Protection during transport and ease of transport 5. Stacking and storage 6. Printed information 7. Environmental function 6

7 1. To protect a product from damage or contamination by microorganisms and air, moisture and toxins. Shelf life of a packaged food is controlled by 3 factors: 1- Food characteristics 2- Packaging characteristics 3- External factors during storage and delivery 7

8 1. To protect a product from damage or contamination by microorganisms and air, moisture and toxins. The packaging must protect the food from (a) biological agents such as rats, insects, and microbes; (b) mechanical damage such as product abrasion, compressive forces, and vibration; and (c) from chemical degradation such as oxidation, moisture transfer, and ultraviolet light. 8

9 2. To keep the product together, to contain it (i.e. So that it does not spill). For items that are granulated, paper-based packages are the best, with a sealing system to prevent infiltration of moisture into the product. Other products are packaged using metal cans, plastic bags and bottles, and glass containers. Another factor in containment is packaging durability in other words, the packaged food has to survive during transport from the food processing facility to the supermarket to the home for the consumer. 9

10 3. Marketing function Packaged food must be identified for consumer use, mainly with label text and graphics. It can also be done by using special shapes for the food package, such as the Coca-Cola bottle. It should be attractive and consumer appealing at the time of sale, for example children. It should give consumer information about the foods in it. It should comply with legal rules and restrictions. The package will also contain important information including ingredients and sell by date. 10

11 4. Protection during transport and ease of transport A package should be designed to make it easy to transport, move and lift. A regular shaped package (such as a cuboid) can be stacked without too much space between each package being wasted. This means that more packages can be transported in a container of a lorry. Unusually shaped packages can lead to space being wasted and this can be costly if thousands of the same package are been transported. 11

12 5. Stacking and Storage In supermarkets and shops, it must be possible to stack packages so that space is not wasted on the shelves. Lost space on shelves is looked up on a lost opportunity to sell to a customer. Also, the package must be designed in such a way that all the important information can be seen by a potential buyer, especially the product name. The next time you visit the supermarket look carefully at the shape of the packages. They are usually the same rectangular / cuboid shape. It is the selection of colors and shades that determine whether the product inside is regarded as a quality, sophisticated or cheap item. Often packages are stacked on top and alongside each other to reduce wasted space. The shape and form of the package determines how efficiently they can be stacked or stored. 12

13 6. Printed information Information that is useful to consumers and companies such as Supermarkets, is printed on packaging. This includes, ingredients, sell by dates, price, special offers, manufacturers address, contact information, product title, barcode and more. The barcode is extremely useful to the shop selling the product. When the barcode is scanned, the computer system automatically determines if the product needs reordering. Also, the price of the product appears at the till. 13

14 7. Environmental function It should not cause environmental pollution from chemical and biological aspects No additional charges should be required for its disposal. It should be recycled to be reused in food packaging It should take up little space in trash cans. 14

15 History of food packaging The history of packaging is as old as the history of mankind. Since the foodstuffs have to be kept and protected, the packaging has been on the agenda. However, in today's sense, packaging requires modern techniques and processes. 15

16 At the beginning of the Stone Age, people consumed their foods in their natural habitats. However, they put their leftovers in natural containers such as hollow tree trunks, pots made from soil, shells of crustaceans, tree leaves and shells and animal skin. They have learned to build higher quality packages than these natural materials. 16

17 In the later times, cubes and casseroles from the soil, baskets from the trees, sacks from natural fibers have been made by humankind. The people who lived in the Palaeolithic period hid their residual food in containers made from such materials. Finally, in the Neolithic Age metal pots and pottery have been used. 17

18 In the region known as Pakistan today, it is mentioned in the historical documents that people of Moenjo-Daro, one of the oldest cities in the world, hid their wheat and barley in closed pots in order to protect them from moisture and pests 4000 years ago. In 3000 B.C., it is expressed that Egyptians, Phoenicians, Persians and Turks could make bottles by blowing liquid glass. 18

19 The Papirus paper was originally developed for writing and used by Egyptians and Greeks in B.C However, the history of paper bags goes back to the 17th century. The actual development in packaging has been in the last 200 years. The metal cans was released in Hermetically sealed glass jars were used to thermally store food in France in 1809, In 1852, paper bag machine was developed in USA. Significant developments occurred in the last 50 years. Therefore, packaging industry has been really big and important area. 19

20 In 1871, corrugated materials for packaging were patented in the USA. In 1884, cereals were first packed in folding boxes. In 1899, the idea of a fully automatic bottling machine was introduced in the United States, and commercialized in In 1906, paraffin-coated paper milk containers were sold (USA). In 1910 waxed cartons were used for cream packaging. In 1912, a regenerated cellulose film was developed. In 1927 Du Pont further developed cellulose films and introduced its product as CELLOPHANE. 20

21 In 1939, ethylene was polymerized for the first time. From the 1960s, polyethylene (PE) began to become widespread. In 1956, Tetra Pak released tetrahedral milk cartons made of paper coated with low density polyethylene extrusions. In 1967, Tetra Pak developed a rectangular Tetra Brik Aseptic (TBA) cardboard system for long-life UHT milk. TBA has since become the main package form for many liquid foods and beverages. 21

22 In the 1970s, the barcode system for retail products was first developed in the USA. In the 1970s, modified atmosphere packed retail foods were released. In the 1970s, PVC was used for beverage bottles. In 1973, Du Pont developed PET bottles that were produced by injection moulding. PET bottles were then used for cola and other carbonated beverages. During the 1980s, co-extruded plastics with oxygen barrier properties and PET coated papers were developed. In the 1990s, digital graphic printing and labels were applied to cardboards in the UK. 22

23 Required qualifications of a packaging material «Well ordered costume is more effective than the letter of recommendation». This saying is also worthful for packaging industry. 1. Expectations of consumers 2. Expectations of manufacturers 3. Expectations in business 23

24 1. It should protect the food material placed in the package against various physical damages, chemical changes and microbial contamination during the period from packaging to consumption. 2. It should represent the food item to the consumer in the most attractive way. 3. It should enable production and shipment of products in accordance with the legal rules. 4. The packaging material should be in sizes that will best accommodate the storage location. 5. Packing of food should function to facilitate the quality control, especially in food inspection. 24

25 6. Packaging should allow easy loading and unloading of food. 7. Developments in the packaging industry have enabled the production of lightweight and low cost new materials. 8. Food packaging wastes should not be physically, chemically and biologically harmful to the environment, so the most appropriate material should be selected in food packaging. 9. Food packaging should not interact with the food ingredient and should not allow migration of toxic materials. 10. It should give the product an attractiveness with its design and color. 11. It should be with low cost. 25

26 Classification of food packagings 1. Primary packaging: in direct contact with the food or beverage, e.g. bottle and cap, carton 2. Secondary packaging: contains and collates primary packs for manual transfer for example, a shrinkwrapped corrugated fibreboard tray or case. 3. Transit (tertiary) packaging: Tertiary packaging combines all of the secondary packages into one pallet, batch etc. 26

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28 Characteristic Properties of Food Packaging Materials When selecting a package for a food item, the following features are considered and the most appropriate packaging material is selected: 1. Water vapor and gas permeability (barrier properties) 2. Heat sealability 3. Resistance to physical factors 4. Flexibility and elasticity 5. Interaction with food 6. Appearance 7. Specific odor and taste 8. Suitability to work with machine 9. Cost 10. Usefulness 11. Informativeness 12. Availability 13. Environmental aspect 28

29 1. Water vapor and gas permeability Permeability It is a mass transfer phenomenon in which some substances dissolved in the polymer surface migrate from the inner atmosphere to the outer atmosphere or vice versa. Mass transfer generally involves three different stages: 1. Absorption and dissolution 2. Diffusion 3. Desorption 29

30 1. Water vapor and gas permeability 1. Absorption and dissolution In order for a molecule to transfer within the polymer, it must first dissolve in the medium it is in. Once the dissolved molecules on the polymer surface reach a certain degree of saturation, they begin to diffuse into the polymer. 2. Diffusion Depending on the concentration and partial pressure of the molecules absorptive on the polymer surface, it is the process of passing from the inner atmosphere to the outer atmospheres or from the outer atmosphere to the inner atmospheres. Diffusion is referred to as the formation of equilibrium concentration by the movements of the dissolved molecules to the polymer area with less concentration. 3. Desorption It is the evaporation or separation of molecules from the polymer. It is the opposite of absorption. 30

31 1. Water vapor and gas permeability The most important concepts to be considered in food packaging are gas (O2, CO2, ethylene, N2), water vapor and odor permeability of packaging materials. Foods absorb or desorb water when they are kept in an environment with a stabile humidity and temperature. For this reason, it is necessary to control moisture exchange during the packaging and storage of food. Packaging material should allow neither drying of food by evaporation of water from it nor its hydration by getting moisture from the environment. 31

32 1. Water vapor and gas permeability Oxygen is the most important permeant that must be controlled since it causes many chemical, enzymatic and microbiological reactions in foodstuffs. For example, packaging of a high fat content fish with a high O2 permeable package can cause food to become inconsumable by allowing its oxidation. The permeability of aroma and odor substances can lead to a loss of flavor in the packaged food or transition of a foreign aroma into food. The flavor permeability of the packaging material varies depending on solubility of the flavor component and external temperature. 32

33 1. Water vapor and gas permeability Factors affecting permeability: 1. Polymer related factors 2. Environmental factors 3. Food related factors 33

34 1. Water vapor and gas permeability 1. Polymer related factors Chemical composition, polarity, free volume (volume), crystal-amorphous structure, density and thickness of the polymer matrix as well as use of the filler materials affect the permeability. In polar polymer matrices, an increase in the diffusion coefficient can be seen, depending on the dissolution of soluble polar organic molecules. As the amount of free volume increases, the permeability will also increase due to increasing diffusion. As the crystal structure increases, the permeability decreases. The permeability decreases as the thickness increases. 34

35 1. Water vapor and gas permeability 2. Environmental factors Temperature and relative humidity are important factors. The temperature especially affects the permeability of small molecules. As the temperature increases, the molecular mobility increases and consequently the density decreases. The polymer membrane becomes more favorable to diffusion. The relative humidity of the environment is an important parameter of water vapor permeability. 35

36 1. Water vapor and gas permeability 3. Food related factors Concentration and molecular size are important factors. Diffusion occurs depending on the difference in concentration of a certain compound between 2 regions. Highly concentrated molecules reach the equilibrium by shifting towards the low concentration region. The diffusion coefficient of the small molecule gas components is higher than that of the large molecule components. 36

37 2. Heat sealability The most important function of packaging is to ensure the protection and integrity of the product. This implies that the pack must be securely sealed. With plastic packaging, this can be achieved on the packing line by either heat sealing, application of a closure, such as a screw cap, or by the use of some form of adhesive system. Sealing strength is influenced by the thickness of the film web. The thicker film does not allow heat to flow so easily to melt the sealing coating or polymer, and when heated, the film retains the heat, allowing the sealant to remain fluid, with a detrimental effect on hot seal strength. Thick film also requires more pressure to bend the film and make intimate contact, particularly on f/f/s (form/fill/seal) machines. 37

38 3. Resistance to physical factors The resistance of the packaging material to physical factors can be grouped into 4 groups : 1. The packaging material must be capable of superficially lengthening and shortening by the influence of environmental factors. 2. It must be resistant to tearing and puncturing. 3. Packaging must be resistant to long-term storage. 4. It must be high in heat resistance. 38

39 4. Flexibility and elasticity Flexible packaging is defined as a package or container made of flexible or easily container made of flexible or easily yielding materials that, when filled or yielding materials that, when filled or closed, can be readily changed in shape. The flexibility of the packaging material allows the product to be protected without tearing and deforming the packaging against external influences during transport. Elasticity is the property of solid materials to return to their original shape and size after the forces deforming them have been removed. If the packaging can return to its original shape after processes such as folding and crushing, it means that it has a high elasticity. 39

40 5. Interaction with food An ideal packaging material does not interact with the food material and does not have a harmful effect on the food. The interaction of the packaging with the food can be physical or chemical. In order to determine whether there is interaction between food and packaging, properties of food is monitored during its shelf life. 40

41 6. Appearance The exterior appearance of the packaging material includes color, transparency, and opacity. It is desired for some foodstuffs to see the product from the outside. For example red and poultry meat. However, in some cases it is desired to the packaging be opaque. Such foods are usually light sensitive foods. Examples are milk, cheese, etc. 41

42 7. Specific odor and taste It is desirable that the packaging material itself is usually neutral in taste and odor. Packaging materials, however, may have their own unique smells, especially arisen from raw materials. In some cases, the presence of odorous substances in the packaging material may be desired. 42

43 8. Suitability to work with machine Especially in large enterprises, food items are marketed after packaging. There must be a fit between the packaging machines and the packaging, the material must be able to go through the metal parts without deformity. Especially, packaging materials should have low friction levels. 43

44 9. Cost The cost of packaging material should be as low as possible. It should be at a cost that is compatible with the food inside. 44

45 10. Usefulness The usefulness of the packaging material may vary according to the consumer preferences. It is an important advantage that the packaging material can be reused for the consumer. It is important to produce the packaging in an easy-to-carry design. 45

46 11. Informativeness The packaging material should be capable of providing a variety of information to the consumer, such as the type, characteristics, storage conditions, preparation and Nutrition facts of the food. 46

47 12. Availability Packaging material should be easy to find. Raw material of the packaging should not be difficult to find. 47

48 13. Environmental aspects Choice of packaging type is made on the basis of a series of trade -offs between many factors, particularly between the amount of packaging and likely product wastage. Consumers are increasingly willing to buy concentrated products in lightweight refill packs. Currently, degradable plastics are used in such non-food items as garbage bags and disposable diapers. A food package must be a sufficient barrier to prevent contamination from the surrounding environment during the intended shelf life of the product. Also, the degradation or decomposition process must not release toxic products that could migrate into the food, making it unsafe. 48