Food Packaging PDF

Food packaging  Learning objectives To understand the To understand the reason(s) why the use of To identify the aims of importance of food food packaging has...

Food packaging  Learning objectives To understand the To understand the reason(s) why the use of To identify the aims of importance of food food packaging has packaging food. labelling. increased. To identify common To recall aspects of examples of food packaging design. packaging.  Over the last 50 years the way we buy food has Due to advances in changed. In the past, some technology, most food food items were usually items are now sold pre- sold ‘loose’ and taken packed. home in a paper bag. Protection Food products often have a long journey from the initial manufacturer until finally being eaten by consumers. They must be stored in warehouses before being transported and distributed to retailers. They are then likely to be stacked in more warehouses before being sold. At all these stages the product may be damaged by careless handling or changes in storage conditions such as light, humidity and temperature. What is the purpose of packaging – write down as many as you can think of? The purpose of packaging prevent protect against prevent physical contamination from dehydration or damage, micro-organisms, dampness; pollution or vermin; protect the product’s nutritional keep the product help to increase a and sensory in peak condition; product’s shelf life. characteristics; Protection The aim of packaging is to contain the product and keep it intact. This means that liquid products do not leak and that dry materials, such as flour, do not spill out. It is sometimes necessary to design packaging that is shaped especially to contain a particular food, e.g. egg boxes, so that the product is held securely and well protected from damage. What criteria would you consider when designing packaging for a food product?  Packaging design When designing packaging it is important to consider the following: Is it easy to handle and open? Is it a convenient shape, so it is easy to stack? Which colours will be used on the packaging? What size of print should be used? (Can consumers read it easily?) Will it be economical to produce? What about environmental considerations? (Will it be recyclable or does it make minimum use of natural resources?) Packaging design Increased rates of production during the last few decades have made it necessary to use different methods and materials to pack and protect food products. However, other factors also determine the choice of materials used, especially in relation to food hygiene and safety. For example, the material must be suitable for the food, as some chemicals present in the food or packaging may react together. Example: Food cans Cans were traditionally made from tin plate sheet, but now more commonly aluminium is used (for drinks). The inside of the can is often sheet coated with lacquers to prevent the cans rusting and reacting with the contents, especially acidic foods.  Paper, board and foil are commonly used to package foods. Board used for food packaging is often coated with a wax of polythene to Example: prevent interaction with contents. Paper, Most paper or board should be discarded before heating, but some products frozen on specially treated board may be cooked in board and microwave ovens. foil Foil trays are suitable for both freezing and heating in conventional ovens.  Examples: Plastics Food packaging uses a wide range of both rigid and flexible plastic materials including: polythene – low density is used as a film wrapping, resistant to water. High density is used for ‘boil-in-the-bag’ products; polyamide (nylon) – provides a very good barrier to oxygen, so used for vacuum packaging, especially for foods containing fat This Photo by Unknown author is licensed under CC BY-NC-ND. polyethlene terephthalate (PET) rigid plastic bottles, light-weight, little risk of breakage and keep the fizz in carbonated drinks polystyrene – expanded polythene used for trays and insulated containers to keep food products cold, e.g. ice cream and sorbets or hot, e.g. coffee, soup and burgers. This Photo by Unknown author is licensed under CC BY-NC.  Cellulose films are used for different types of food packaging, because they have a range of characteristics such as different degrees of moisture proofing. Example: Some cellulose films are heat sealable. Cellulose films They can be used, for example, as window patches in cartons. Example: Glass Glass has been used for food packaging for a long time but tougher, light–weight containers, sometimes protected by a sleeve of expanded polystyrene have been developed more recently. However, glass is still very popular and is used exclusively for many products, e.g. jam.  Review of the learning objectives TO UNDERSTAND THE REASON(S) TO IDENTIFY THE AIMS OF TO RECALL ASPECTS OF TO IDENTIFY COMMON WHY THE USE OF FOOD PACKAGING FOOD. PACKAGING DESIGN. EXAMPLES OF FOOD PACKAGING. PACKAGING HAS INCREASED. Modified Atmosphere Packaging (MAP) and ambient foods Foundation Learning objectives To understand the purpose of Modified Atmosphere Packaging (MAP). To know the type of packaging used in MAP. To understand the purpose of vacuum packaging. To recognise ambient foods. To understand the processes involved in packaging ambient foods products.  Modified atmosphere packaging (MAP) is a technique used to lengthen the shelf-life of food products of minimally processed or fresh foods. Modified The air surrounding the food in the package is changed to atmosphere reduce the activity of microorganisms. packaging Meat, fish, fruits and vegetables often use the method during packaging. Equilibrium modified atmosphere packaging (EMAP) is most commonly used for cut fresh-cut produce. Food preservation Chilling foods can have a preservative effect by retarding microbial activity. However, the shelf-life of a chilled product can be increased by modifying the gases surrounding the food.  Modified atmosphere packaging is the enclosure of a food, e.g. bacon, in a package in which the Modified atmosphere has been changed by altering the proportions of carbon dioxide, oxygen, nitrogen, water vapour and trace gases. Atmosphere The process limits microbial as well as biochemical Packaging activity. (MAP) This modification is performed by gas flush packaging – air is removed and replaced by a controlled mixture of gases. Proportion of gases in packaging Proportion of gases Thermoplastic polymers Nearly all packaging for this process is based on thermoplastic polymers. The reasons for this are that they: have greater flexibility, i.e. can be formed into different shapes; are light in weight; provide a gas barrier; can be sealed easily; can be printed on. are resistant to physical pressures of manufacturing, distributing and retailing have good aesthetic properties can be multi-layered with other materials to enhance overall properties. Vacuum packaging Food is placed within an impermeable package and air is removed. With fruit and vegetables, packaging films of different permeabilities are used to achieve the correct atmosphere to take account of the product’s natural respiration. Vacuum packaging at home If vacuum packaging food in the home, the food should be eaten within ten days. The packet should be sealed and left in the fridge until it is eaten to keep it safe. Once the packaging is opened, it should still be kept in the fridge like other chilled foods and eaten within two days. Ambient food products AMBIENT FOODS ARE THOSE CANNED AND ASEPTICALLY LONG SHELF-LIFE PASTEURISATION AND SOME AMBIENT FOODS ARE WHICH ARE STORED AND PACKAGED FOODS STERILISATION ARE THE TWO NOT HEAT TREATED SOLD AT ROOM MAIN HEAT PROCESSES USED. TEMPERATURE. Ambient food products Only harmless micro-organisms can be allowed to survive processing treatment. Canned fruit juice, which may contain spore-forming bacteria, will This Photo by Unknown author is licensed under CC BY-SA-NC. be safe as long as the pH is low enough to ensure the bacterial growth could not occur. Low-acidic foods undergo a rigorous heat treatment known as the ‘Botulinum cook’ – to reduce the numbers of clostridium botulinum spores to a safe level. This is because these spores are very resistant to heat. Ambient foods, such as cereals, rice and pulses must be stored carefully. The moisture content for each needs to be kept low to prevent mould and yeast spoilage. This Photo by Unknown author is licensed under CC BY-NC.  To understand the purpose of Modified Review of Atmosphere Packaging (MAP). To know the type of packaging used in MAP. the learning To understand the purpose of vacuum packaging. To recognise ambient foods. objectives To understand the processes involved in packaging ambient foods products.