GCSE FPN - Dairy theory PPT for gamma.pptx

GCSE FOOD PREPARATION AND NUTRITION MILK Nutritional value of milk Called a ‘complete food’ – contains all the indispensable amino acids and many if the essential nutrients that the body needs Nutrients are easily absorbed by most people An emulsion – tiny globules of fat floating around in water Mi...

GCSE FOOD PREPARATION AND NUTRITION MILK Nutritional value of milk Called a ‘complete food’ – contains all the indispensable amino acids and many if the essential nutrients that the body needs Nutrients are easily absorbed by most people An emulsion – tiny globules of fat floating around in water Milk is made up of: 85% water 15% nutrients: 4.8% Carbohydrates (lactose) 3.5 % HBV protein 3.5 % Fat 0.8 % vitamins (A, D, C, water soluble B) 0.7 % minerals (calcium, phosphorus, sodium, potassium, 5% 5% 4% 1% 1% 8500% Water lactose fat protein vitamins minerals GCSE FOOD PREPARATION AND NUTRITION PRIMARY PROCESSING - MILK Where does milk come from Milk is produced by all female mammals to feed their young, such as cows, goats, buffalo, camels and sheep All mammals stop drinking milk once they are old enough to eat solid food. Humans are the exception. We continue to include milk in our diets Dairy cows need to have given birth to calves before they can start producing milk Cows are milked every morning and evening to keep the milk production going Most cows can produce milk for about three years before being slaughtered for their meat Cows graze on outdoor pasture where they eat grass, In winter they are inside in sheds and fed grass silage, maize and special cattle food Average 20 litres a day per cow Milk collected and stored in holding tanks How does a cow make milk (3mins) Milking cows (6mins) GCSE FOOD PREPARATION AND NUTRITION TYPES OF MILK Types of milk Milk is bottled according to its fat (cream) content. Most milk has a fat content of about 4% During processing the fat can be removed or reduced WHOLE MILK (BLUE TOP) – 3.9 % fat CHANNEL ISLAND MILK (GOLD TOP) Usually consumed by babies and – 5.1% fat From Jersey or young children due to its higher fat Guernsey breed of cows, milk has a content higher fat content SEMI SKIMMED MILK (GREEN TOP) – 1.7% Most commonly drunk milk % 1 MILK (ORANGE TOP) – 1% Not very commonly sold as other types of milk SKIMMED MILK (RED TOP) – 0% 0.5% Lowest fat content milk FILTERED MILK – 0% - 3.9% The milk has been filtered through ceramic filters. Can be stored unopened in the fridge for 3 weeks and opened in the fridge for 7 days Fresh milk has to be stored in the fridge, at 5 °C. Away from strong smelling foods and with a tight lid. Do not store in sunlight. Do not mix old with new milk GCSE FOOD PREPARATION AND NUTRITION Be law all milk must be heat treated to destroy any pathogenic bacteria and ensure that it is safe to drink This takes place at the milk processing PRIMARY PROCESSING - MILK plant Pasteurisation Raw (untreated) milk must be pasteurised The milk is heating to 75°C for 25 seconds Then rapidly cooled to 5°C These temperatures destroy most pathogenic bacteria making the milk safe to drink It doesn’t affect the overall flavour Gives a longer shelf life The pasteurised milk is then sealed into containers for sale If the milk is left to settle, pasteurised milk will form a cream later at the surface To prevent this, milk can be homogenised Milk from farm to fork (2mins) Pasteurisation (2mins) GCSE FOOD PREPARATION AND NUTRITION PRIMARY PROCESSING - MILK Homogenisation A process which forces pasteurised milk under pressure through very fine mesh This breaks up the large fat (cream) globules into smaller particles The cream is evenly distributed throughout the milk Gives uniformed consistency and creaminess It gives a smooth texture, rather than slightly lumpy Most milk sold in the UK is homogenised Unhomogenised milk is better to use to make yoghurt Homogenisation GCSE FOOD PREPARATION AND NUTRITION PRIMARY PROCESSING - MILK Sterilisation Milk is treated with higher temperatures to destroy nearly all the bacteria in it Milk is heated to around 50°C, homogenised, poured into glass bottles and closed with an airtight seal The bottles are carried along a conveyor belt through a steam chamber They are heated to a temperature 110-130 °C for approx. 10-30 minutes Bottles are cooled and are ready for sale The process can alter the flavour and colour It can slightly reduce the water soluble vitamins B and C Unopened bottles or cartons of sterilised milk will keep for approx. 6 months without refrigeration Once opened, sterilised milk mist be treated as fresh milk and used within 5 days GCSE FOOD PREPARATION AND NUTRITION PRIMARY PROCESSING - MILK Ultra Heat Treated Milk (UHT) Fresh milk is heated to about 135°C for 1-2 seconds to kill off harmful bacteria Its cooled for 1-2 seconds before being sealed into tetra-pack packaging Flavour and nutrients are very similar to fresh milk due to the very fast heat treatment Available in different fat content just like pasteurised milk Also called long life milk Storage Sealed UHT milk can be stored in a cupboard, unopened, at room temperature for up to 6 months Once opened, it must be treated like fresh milk and stored in the fridge GCSE FOOD PREPARATION AND NUTRITION Uses of Fresh, UHT and Sterilised Milk Enriching (adds nutrition to) foods E.g. custard and sauces Holds dry ingredients together E.g. cake mixture, biscuit mixture, pastry and bread doughs Adds moisture and changes consistency of food E.g. makes sauces thinner/runnier Adds creaminess to foods Milk in tea, hot chocolate, smoothies USES OF MILK GCSE FOOD PREPARATION AND NUTRITION Evaporated milk 50% of the water us evaporated from the milk Its then homogenised to prevent the fat from separating out Its poured into cans which are sealed Can are heated for 10 minutes at 115-20°C Processing gives it a slight caramel flavour and richer colour Has a higher level of sugar 9.1g per 100ml It has a fat content of 4-10% Storage Can be stored unopened in a kitchen cupboard for up to 12 months Once opened, it must be treated like fresh milk, stored in the fridge at 5°C Uses Pour over desserts Tarte au chocolat Add to coffee PROCESSED MILK GCSE FOOD PREPARATION AND NUTRITION Condensed Milk Fresh milk is heated to a temperature of 110-115°C for 60-90 seconds It is then homogenised Its sweetened with sugar Its then evaporated at 55-60°C Its cooled rapidly to 30 °C and canned Its 3 times more concentrated than fresh milk Its very thick and sweet, syrupy consistency Storage Can be stored unopened for a cupboard for up to 12 months Once opened should be stored in the fridge Can a stored for a day or two at room temperature in a lidded container due to the high heat treatment and added sugar Uses Toffee, caramel and fudge Millionaire shortbread Used as milk in hot countries or no access to a fridge PROCESSED MILK GCSE FOOD PREPARATION AND NUTRITION Dried Milk Produced by evaporating the water in milk The milk is pasteurised and homogenised The milk is sprayed into a chamber of circulating hot air causing the droplets of milk to lose their water content and fall to the floor as fine, dried powder Storage In an airtight container, has a shelf life of up to 12 months Once reconstituted with water it can be used just like fresh milk and stored in the fridge Dried milk has similar nutritional value as fresh milk, although some B vitamins are lost Dried skimmed milk mixes very easily with water Dried whole milk powered tends to form small lumps wen mixing with water Uses No access to a fridge, just need to add water Similar to baby formula but this is fortified with lots more nutrients PROCESSED MILK GCSE FOOD PREPARATION AND NUTRITION SECONDARY PROCESSING - CHEESE Cheese is made by the secondary processing of milk. Nutritional value of cheese Cheese can be made from all types of milk but most commonly from cow, goat, sheet and buffalo milk Cheese is a composition of coagulated milk proteins and fats Same nutrients as found in milk but in greater quantities due to the reduced water content Cheese is high in: HBV – high biological protein Calcium Fat Vitamins A and D Some B vitamins Phosphorus Zinc It does not contain vitamin C or fibre – GCSE FOOD PREPARATION AND NUTRITION FRESH CHEESE Fresh cheese Cottage cheese - 4g fat per 100g Uses - salads, sandwiches, jacket potatoes Cream cheese - 24g fat per 100g Uses – cheesecakes, soups, jacket potatoes, sandwiches Fromage frais - 6g fat per 100g Uses – dips, cheesecakes Ricotta - 10g fat per 100g Uses – cheesecakes, filled ravioli Mozzarella - 22g fat per 100g Uses – pizza, salad Mascarpone - 42g fat per 100g Uses – cake frosting, cheesecakes, sweet and savoury dishes GCSE FOOD PREPARATION AND NUTRITION SOFT CHEESE Soft cheese Brie- 28g fat per 100g Uses – Cheeseboards, crackers, quiches Camembert – 28g fat per 100g Uses – Cheeseboard, deep fried, dip Feta – 16-23g fat per 100g Uses – Soups, salads GCSE FOOD PREPARATION AND NUTRITION SEMI HARD CHEESE Semi hard cheese Edam - 25g fat per 100g Uses – cheeseboards St Paulin – 25g fat per 100g Uses – cheeseboards Halloumi –25g fat per 100g Uses – Side dish, burger topping GCSE FOOD PREPARATION AND NUTRITION HARD CHEESE Hard cheese Cheddar - 34g fat per 100g Uses – cheeseboards, lasagne, cottage pie, quiche, crackers, sandwiches Red Leicester– 34g fat per 100g Uses – cheeseboards, lasagne, cottage pie, quiche, crackers, sandwiches Emmental - 28g fat per 100g Uses – cheeseboards, lasagne, cottage pie, quiche, crackers, sandwiches Parmesan –28g fat per 100g Uses – cheeseboards, lasagne, cottage pie, quiche, crackers, sandwiches Manchengo - 36g fat per 100g Uses – cheeseboards, lasagne, cottage pie, quiche, crackers, sandwiches GCSE FOOD PREPARATION AND NUTRITION BLUE CHEESE Blue cheese Stilton - 36g fat per 100g Uses – cheeseboards, soup Gorgonzola– g fat per 100g Uses – cheeseboards Roquefort –g fat per 100g Uses – cheeseboards, quiche Processed cheese types Cheese slices Uses – burgers Cheese strings – Uses – Lunch boxes Spreadable cheese – Uses – sandwiches GCSE FOOD PREPARATION AND NUTRITION 1. Starter culture – Specific bacteria called starter culture is added to pasteurised milk. This culture ripens the milk by fermenting the lactose into lactic acid which helps develop the flavour and aroma of the cheese 2. Rennet - Once enough lactic acid has been produced, rennet is added to the milk (originally an enzyme from calves' stomachs, now uses artificial rennet) 3. Curds and Whey – The rennet helps the milk coagulate, forming curds and whey 4. Cutting – The cheese is cut into blocks to help removed the whey 5. Cooking - The curds are then ‘scalded’ by heating to encourage syneresis- when whey being expelled from the curds 6. Draining/pressing - The cheese is pressed to force out any remaining whey and to form its final shape. The more whey that is squeezed out the harder the cheese will be 7. Milling - The cheese is cut into blocks and left to mature for up to 24 months 8. Flavouring – flavouring are added depending on the type of cheese HOW IS CHEESE MADE GCSE FOOD PREPARATION AND NUTRITION HOW IS CHEESE MADE GCSE FOOD PREPARATION AND NUTRITION HOW IS CHEESE MADE VIDEOS Cheese from farm to fork (school visit) (22 mins) How its Made - Blue Stilton Cheese (4 mins) How is cheese made - Science Scrapbook (6 mins) How its made - mozzarella (5 mins) GCSE FOOD PREPARATION AND NUTRITION Producing different types of cheese The appearance, colour, flavour and texture of the final cheese depends on: The typeof milk used The cheesemakers recipe The manufacturing method How much water is removed from the curds and whey Any additional flavourings and colourings such as salt, herbs, fruits and moulds How long the cheese has been stored for (this affects the age/maturity of the cheese Generally, the harder the cheese, the stronger than flavour Cheese that are used within a few weeks of production tend to have a milk flavour and a creamy texture TYPES OF CHEESE GCSE FOOD PREPARATION AND NUTRITION Bacteria and Cheese Soft cheeses such as brie, feta and camembert may be contaminated with the bacteria listeria monocytogens Listeria will grow to harmful levels even when the cheese is correctly stored in a cold fridge Women are advised to avoid eating soft cheeses during pregnancy because they are approx. 20 times more likely to develop listeriosis, compared to other healthy women A listeriosis infections (caused by listeria) resembles a mild, flu-like illness but it can cause septicaemia, miscarriages, infection of the newborn baby and, possibly, still births. Listeria is killed by high heat BACTERIA AND CHEESE GCSE FOOD PREPARATION AND NUTRITION Storing Cheese All cheese should be covered or wrapped to prevent drying out and crosscontamination It should be kept in a fridge at 5 °C Softer, creamier cheese tends to have a very short shelf life and must be consumed by the ‘use by’ date Cheese can be frozen but the texture may be affected once defrosted Uncooked cheese tastes better if it is taken out of the fridge 30–60 minutes before it is to be eaten, but be careful to avoid food contamination! STORING CHEESE GCSE FOOD PREPARATION AND NUTRITION Uses of cheese Normal state - Cheese can be eaten its normal state: on crackers, cheeseboard, in sandwiches, children's snacks or in a salad Flavour and texture – broccoli and stilton soup, cheese, cauliflower cheese and pizza Nutrition - protein, calcium, fat, vitamins Colour and texture – golden crispy tops to dishes such as cauliflower or macaroni cheese (au gratin) All cheeses have carrying colours, textures, strengths of flavour which must be considered when dividing which cheese o use when preparing food Soft, creamy cheese, such as brie or ricotta, have a more gentle flavour than hard cheeses like parmesan or gruyère USES OF CHEESE GCSE FOOD PREPARATION AND NUTRITION EFFECTS OF HEAT CHEESE Effects of heat on cheese Melting point – Cheese melts at 65°C, making it spreadable or stringy and it will ‘dissolve’ into food cooked at high temperatures Too much heat – this will ‘burn’ both the protein (casinogen) and the fat in the cheese, making it bitter, hard and tough Absorbing fat - cheese is generally grated or diced before cooking and is often mixes with a starchy ingredient which will absorb the fat released from the cheese by the heat More easily digested – Cooked cheese is more easily digested than uncooked cheese. As the cooking temperature continues to rise, cheese will brown and eventually burn. Brown, practically burned cheese has a particular distinct flavour found in an ‘au gratin’ topping and cheese on toast Heating in cheese production – when cheese is made, the curds are heated. The heat changes the proteins that were already denatured by acid and the rennet, making them bunch closer together, expelling the whey to make the cheese firm and less likely to spoil Viscous - Most rennet-set cheeses melt easily and when enough protein bonds are broke, the cheese turned from a sold in to a viscous liquid (thick and sticky) Returns to a solid when - Acid set cheeses, such as halloumi, paneer, some whey cheese and fresh goat cheese have a protein