Food processing and production

1. Food processing and production

2. What I need to know How wheat is made into flour http://resource.download.wjec.co.uk.s3.amazonaws.com/vtc/2015-16/15-16_12/whereFoodComesFrom.html • What primary and secondary processing means Wheat • What wheat is ( how is it grown etc.) • Secondary processing of wheat: -different types of flour and their uses in cooking -Flour made into bread and pasta ( how this happens both domestically and commercially) Milk • Primary processing of milk ( how it is made safe to consume and meets consumers needs) • Different types of milks and their uses in cooking • Secondary processing of milk -Milk into butter, cream, yoghurt and cheese (how it is done and different types) -What the red tractor symbol means and how that relates to milk and wheat processing

3. How flour is milled Primary and secondary processing of Wheat Step 1: the wheat grains are blended with other varieties and washed to remove grit and dirt. Step 2:Huge rotating rollers crush the grains at varying speeds The crushed grain is sieved and this produces flour. Step 3: If white flour is wanted, the bran is removed by further rolling. The process can be adjusted to produce the required type of flour. What is it? Wheat grows particularly well in the UK although can be grown worldwide. It is easy and cheap to grow hence its popularity. The grain wheat is milled to make flour. Flour is used to make lots of different food products including bread, pasta, biscuits and cakes, Wheat grains are at the top of the plant they are closely packed together in clusters called ears. Each ear is made up of around 45-50 grains A grain of wheat A grain of wheat has 3 distinctive parts Bran layers- the course outer Wheat germ- a new plant would grow from the part Endosperm- the starchy store of food from which the plant grows Different parts of the wheat grain are used to make different types of flour Types of flour Primary processing Flours can be defined by their extraction rate : that is how much of the whole grain is used Wholemeal flour Extraction rate of 100% means that nothing has been removed from it. It is light brown colour. It has the highest fibre content. This logo is often used on organically produced flour (no chemicals) Secondary processing of flour Other ingredients are then added to flour at home or in food factories to turn them into these four main products. Different flours give different tastes and textures. Brown flour Extraction rate of 85-90% ( 10-15% of the grain is removed as bran White flour extraction rate of 70-75% ( the bran, germ, fat and some of the minerals have been removed) UK law states that all flour apart from wholemeal flour has to be fortified with iron, calcium thiamin and niacin. This replaces the B vitamins that have been lost in processing Pasta ( fresh and dried) Bread Biscuits Cakes

4. Primary and Secondary processing of milk Main types of milk in the UK There is a wide variety of milk available. Cows milk is the most popular in the UK. Other main sources are goats and sheep. Once the cows have been milked (this happens twice a day) it is stored in tanks at 4˚c until it is taken to a dairy to be processed. Homogenisation Milk is mainly water. It is an emulsion which has tiny drops of fat suspended in it. As oil and water do not mix the fat naturally rises to the top of the milk. However today we do not buy milk like that, this is because milk is homogenised. This is a process in which milk is forced at high pressure though small holes. This breaks up the fat globules so they are dispersed in the milk. Heat treatment Pasteurisation Most of the milk in the UK has been pasteurised. This is the prefer method. It is heated to a temperature of at least 72c for a minimum of 15 seconds and a maximum of 25 seconds. It is then quickly cooled to below 6c This kills harmful bacteria, has little effect on the on the nutritional value of the milk and extends the shelf life. Sterilised milk Heated to a temperature of above 100c for approximately 10-30 minutes and then is cooled quickly. It destroys nearly all the bacteria, however unlike pasteurised changes the taste and colour ( sweeter and browner due to the caramelisation of the milk sugars) It also destroys some B vitamins. One positive is that it can be stored, unopened in bottles or cartons for several months without being in a fridge, however once opened it must be treated as fresh. UHT (ultra heat treated milk) Heated to a temperature of at least 135c for 1 second All bacteria is killed. Unopened packs have a longer shelf life, but must be treated as fresh once opened. Little effect on the nutritional content and flavour. Primary processing Look out for this symbol on milk Some milk producers are also using this symbol Other types of milk Milk can be purchased in other ways, the way these are processed changes their organoleptic properties (flavour, colour, texture), their uses and their shelf life . Condensed milk Evaporated milk Dried milk

5. Secondary processing of milk Cream Yoghurt Cream is the fat found in the milk. It is separated from the milk by rotating it at a very fast speed. The cream is then pasteurised to destroy any harmful pathogenic bacteria and any enzymes that may cause spoilage and lead to a shorter shelf life. In the UK cream is categorised by how much fat it contains. Yogurt is made by fermenting milk with harmless bacteria. Most yoghurts are made with cows milk but it can be made with goats milk or soya . Low fat yoghurts are made with skimmed milk, richer ones with full fat milk. Milk is incubated and the harmless bacteria is added This changes the lactose in the milk into lactic acid. The lactic acid causes the milk to coagulate/ thicken and gives its distinctive tangy taste Milk is homogenised To distribute the fat particles evenly, resulting in a creamier texture Milk is pasteurised To remove all harmful bacteria Yoghurt is left to set until it reaches the right acidity level Fruit or flavourings are then added Cheese There are many different varieties of cheeses, some are traditionally made in the UK e.g. Cheddar. Others are from around the world e.g. Brie from France, Parmesan from Italy. They are made from different types of milk (mostly cows but sometimes goats). Slight variations in the methods of making can result in different flavours and textures of cheeses. Butter A starter culture is added This changes the lactose in the milk into lactic acid. The lactic acid causes the milk to coagulate the protein in the milk, preserves the cheese and also helps develop the flavour Cream is churned to separate the fat from the water. The fat is the butter. Unsalted butter- no additional ingredients added Salted butter- salt is added for flavour Clarified butter- butter is melted and the fat that rises to the top is separated and used for cooking Ghee- a form of clarified butter is used in Indian cooking Spreadable butter – butter that has oil added which means it is spreadable straight from the refrigerator Butter by law has to have a fat content of between 80 – 90%. There is no such thing as low fat butter or reduced fat butter. These are categorised as spreads. However they are sometimes marketed under the brand name which is confusing! Types of cheeses Hard Cheddar , Parmesan Semi hard Cheshire, Wensleydale, Edam Soft ripened Brie, Camembert Blue Stilton, Roquefort, Gorgonzola Fresh Mozzarella, Cottage cheese Rennet is added and the mixture is left to set The enzyme in rennet coagulates the milk and turns it into solids- curds and whey For soft cheese the whey is left to drain away naturally. For hard cheese the curds are heated and piled on top of each other to release more whey The cheese is then milled and then salt may be added and the curds are pressed into moulds The cheese is left to ripen The temperature and humidity is controlled to produce different types of cheese. As the cheese ripens the colour, flavour and rind of the cheese develops. Be careful Elmlea cream and margarine are not examples of secondary processing of milk as they do not contain any! Processed cheeses are: cheese slices (Kraft slices), Cheese Strings and spreadable cheese (Dairylea)

6. Exam practice questions Use the information sheets to help you to answer the following questions Describe what is meant by primary processing. Include reference to two examples in your response. [4] ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 2. Describe what is meant by secondary processing . Include reference to two examples in your response. [4] ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 3. Giving examples, explain the term extraction rate of wheat [4] ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 4. State 3 different methods of heat treating milk (3)

7. Exam practice questions ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 5. Explain what is meant by homogenisation (3) ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 6. Explain why milk is pasteurised before making it into cream, yoghurt and cheese ( 3) ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 7. Name 3 types of cream and give an example of a use in cooking for each (3) ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 8. Name 3 types of butter and give an example of a use in cooking for each (3)

8. Exam practice questions ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 9. Explain how milk is made into yoghurt (4) ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 10. Explain how milk is made into cheese (4) ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 11. Name 3 types of cheese and state which country they come from (3) ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 13. Name 3 types of flour and give an example of a use in cooking for each (3) ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 14. Explain what the red tractor symbol means on milk products (3)

9. Making your own cheese at home Cottage cheese Cheese has always been a way of storing a surplus of milk for use when the cow or sheep were dry and making your own cheese at home is a great way to store any surplus milk you may find yourself with (method of food preservation). All cheeses are made from the coagulated lumps from milk – the curds – with the liquid part called the whey, hence curds and whey. Although a lactic starter can be used when making cottage cheese, it is not necessary, the same chemical reaction of turning the milk, or curdling, can be obtained from the use of vinegar or lemon juice which most people have in their kitchen. • Equipment to Make Cottage Cheese: • Saucepan – stainless steel or enamelled (avoid aluminium) • Wooden Spoon • Fine Sieve preferably metal • Ingredients for Cottage Cheese: • 2 pints (1200 ml) semi-skimmed or skimmed milk • 2 tablespoons (30 ml) lemon juice or white vinegar • Pinch of salt • Method for Cottage Cheese: • Pour the milk into the saucepan. • Heat on hob until it is very hot, but do not boil, stirring occasionally with the wooden spoon. • Allow to cool for a couple of minutes. • Add 2 tablespoons (30 ml) of lemon juice or vinegar. • Stir and watch the hot milk separate into the curds and whey. • Allow to cool further. • Pour the curds and whey through a sieve to catch the curds. www.allotment-garden.org

10. Video links Jimmy's food factory: Homogenisation http://www.bbc.co.uk/programmes/p011t4p1 Jimmy's food factory: cheese/ processed cheese http://www.bbc.co.uk/programmes/p011lyf6 How wheat is made into flour http://resource.download.wjec.co.uk.s3.amazonaws.com/vtc/2015-16/15-16_12/whereFoodComesFrom.html Jimmy's food factory: Yoghurt http://www.bbc.co.uk/programmes/p011lc0f

11. Keywords