PROPERTIES OF FOOD

Food commodities

You will gain an understanding of: Meat Fish Eggs Dairy products Alternative proteins Cereals Pulses Fats and oils Fruit and vegetables Sugar and sugar substitutes

MEAT Lean meat is the muscle of the animal. The muscle fibres are

bound together in bundles by thin sheets of connective tissue. Muscle fibres contain the proteins myosin and actin, connective tissue is made up of proteins called collagen and elastin. Collagen is pearly white and forms gelatine when cooked.

Page 80- draw out picture A mixture of pigment in the muscle gives meat its colour. The

main pigment is myoglobin. Invisible fat is found in the connective tissue of muscles and is

described as marbling.

What is the nutritional value of meat? How should it be stored? List the different types and cuts of meat.

Cooking methods for meat Grilling Shallow frying Roasting Braising Stewing

How can meat be tenderised? Activity 4.1

CHECK YOUR UNDERSTANDING

Complete an informative factsheet on meat. (A3)

POWERPOINT ON MEAT. Complete an informative PowerPoint on the usefulness of meat

in the diet. Include the following:

Structure Nutritional value Types and cuts Choice of meat Cooking methods Storage Recipes using meat

Practical work

Plan, prepare, cook and serve a dish containing mincemeat.

I.e.- chilli, spaghetti Bolognese, lasagne, Sheppard's pie.

FISH Fish is classified into 3 groups- white, oily and shell. The

government advises that at least 2 portions of fish should be eaten each week, and one should be oily.

The structure of muscle in fish is made up from segments of short fibres called myomeres, which gives fish its characteristic flaky texture. The segments are separated by fine connective tissue which is very fragile and converts to gelatine during cooking.

Cooking improves the colour and flavour of fish. Fish is a very good source of protein, containing between 15 and

20g. Oily fish is a good source of omega 3 oils. List 3 examples of each of the types of fish. (white, oily, shell) What is a Cephalopod? What is the difference between a Crustacean and a mollusc?

fish How should fish be stored?

How should fish be cooked?

Cuts of fish- draw them out.

What are the different methods for preserving fish- Explain? Salting, marinating- adding an acid can improve shelf life,

drying, smoking- mackerel, canning and freezing.

4.6, 4.7- use A3 files for information.

practical

Plan, prepare, cook and serve a dish containing fish:

Fish cakes Prawn curry

EGGS The egg consists of 3 main parts- Shell- 10% of the egg, primarily

phosphate and calcium carbonate. Egg white- (albumen) 60% of egg, divided into thick and thin white. Egg Yolk- yolk is held in position by the chalazae, 30% of the egg. Draw out structure of egg- pg 86.

Eggs contain valuable amounts of iron and HBV protein. Eggs are also a useful source of fat, vitamin A, calcium, and contain a small amount of vitamin A and B group.

What sizes can eggs be brought in?

Eggs Find out what the Lion quality mark means.

What are the different systems of egg production? Find out about them? (battery, deep litter/barn, free-range)

List the different uses of eggs and explain each one- Analysis.

ACTIVITY 4.9, 4.10, 4.11

Make a savoury and sweet egg dish- research recipes on the internet

I.e.. Quiche and Mousse

EGGS- Importance of eggs in the diet.

Produce an informative factsheet/ PowerPoint on the uses of eggs in cooking, download some recipes from the internet. You could also include the nutritional content of eggs.

Chocolate mousse. Ingredients.

200g plain chocolate 4 eggs separated 2 oz butter ½ pt double cream

Dish

Method

1) Break chocolate up and melt in microwave.

2) Remove, and stir in butter. 3) Separate eggs, and

gradually add in yolks to chocolate mix.

4) Whisk whites until light and fluffy.

5) Whisk cream and stir into chocolate mixture.

6) Gradually fold in whites to chocolate mixture.

7) Put into dish and refrigerate until set.

QUICHE Ingredients

8 oz plain flour 4 oz margarine

1 onion 6oz cheese Seasoning 4 eggs 1/4pt milk

Flan dish

Method;

1. Preheat oven to 180c.2. Rub fat into flour until fine

breadcrumbs.3. Gradually add water until dough

is formed.4. Roll out on floured surface. Put

in dish.5. Grate cheese, slice onion, mix

eggs and milk together.6. Put filling in quiche, pour egg

mixture over. season7. Bake for 20 mins.

MILK AND DAIRY PRODUCTS Milk and milk products are an important source of protein, B

Vitamins, Calcium, Zinc and Magnesium. Milk is a useful source of HBV protein. Although milk contains

fat, the amount is dependant on the type of milk.

List the different types of milk, and the uses of milk. What are the 2 different proteins in milk?

Butter is a natural dairy product, which is a water-in-oil emulsion made from cream. It contains about 80% fat, protein, vitamin A and D and Calcium.

Butter is used for a variety of purposes. Explain them.

DAIRY Cont… Cream is made by separating the fat and solids from the milk. It is a fat-

in-water emulsion. Protein is found in small amounts in cream, as is calcium and vitamin A

and D.

What is cream used for?

Cheese is made from milk protein coagulated by the addition of an enzyme known as rennet, which produces milk solids (curd) and liquid (whey), which is drained off. Cheese is a HBV protein.

List the different types of cheese and their uses. It is high in Vitamin D and A and calcium and phosphorus.Yoghurt is made by heating milk that has been heat treated with 2 cultures.

It is a good source of calcium, protein, potassium, phosphorus and thiamine.

Practical

Plan, prepare, cook and serve a dish containing milk.

Complete activities on dairy: 4.12, 4.14, 4.15, 4.17

ALTERNATIVE PROTEIN SOURCES. These are designed to imitate the sensory qualities of meat, they are

also known as MEAT ANALOGUES. They are a useful source of HBV protein, as well as containing some

fibre and being very low in saturated fat. TVP is also a very good source of Vitamin B12. Quorn contains iron and zinc also.

Different types include Myco-protein, soya dairy, TVP, Tofu and Wheat protein as well as Tempeh and Miso.

Find out about the different alternative protein sources, and their uses- research using the internet.

ACTIVITY 4.18- investigate meat alternatives on the market- use supermarket websites to do this.

Practical

Plan, prepare, cook and serve a dish including:

Quorn Soya Tofu

CEREALS These are cultivated grasses, where the grains are used as a food

source. The most important cereals are wheat, maize, rice, oats, rye and

barley. Most cereals are known as staple foods, because they make up the

bulk of the diet. Intake of wholegrain cereal can decrease risk of CHD and type 2

diabetes.

Explain the nutritional content of cereals. Explain the different types and uses of cereals, include types of pasta. Draw out the structure of a rice and wheat grain. Activity 4.19, 4.20, 4.22

Wheat flour

The extraction rate of flour determines the wheat found in the flour.

100% extraction rate- whole-wheat or wholemeal flour

85-90% extraction rate- brown flour 70-72%- white flour.

PULSES These are seeds of plants belonging to the leguminosae family,

known as legumes. Peas, beans and lentils are in this family. These are a LBV protein. They are also a useful source of

carbohydrate, soya beans and chick peas are a rich source of calcium, green lentils are a rich source of iron, soya beans are a rich source of zinc. They are low in fat and high in fibre.

These are useful proteins for vegetarians.

Outline choices and uses of pulses.

Activity 4.23/ 4.24

FATS AND OILS These are obtained from animal and plant sources. Fats and oils are mixtures of TRIGLYCERIDES, which are formed

from molecules of fatty acids joined to one molecule of glycerol. A fatty acid is made up of a chain of carbon atoms with hydrogen atoms attached.

There are 2 types of fatty acid that make up fats and oils, they are; Saturated fatty acids- solid at room temperature. Unsaturated fatty acids- polyunsaturated and mono-unsaturated-

liquid at room temperature. Fat is a concentrated source of energy. Fats contain the fat-soluble

vitamins A,D,E and K Some oils are beneficial to health- Omega 3/ Omega 6 oils.

Outline the main types of fats and oils, and their uses. Activity 4.27- page 107

FATS AND OILS Cont..

Uses- aeration- creaming Flavour Flakiness in puff pastry Shortening- crumbly texture Plasticity- fats soften over a range of temperatures, each fat has its own

melting point. Cooking Spreading Sauce-making- Roux Glazing

Check your understanding- page 108.

Fruit and vegetables Although fruits and vegetables look very different, the edible parts

of them consist of similar types of cells. The cell has an outer wall, which is mostly made of cellulose.

PAGE 109- draw the structure of a fruit and veg cell. Fruits and vegetables are a rich source of many nutrients,

including carbohydrate and sugar, vitamin C, fibre, vitamin A, potassium, vitamin E, Vitamin B group, iron, calcium, fat and protein.

The government recommends that 5 portions of fruit and vegetables should be eaten daily. A diet rich in fruit and vegetables may lessen the risk of CHD.

Fruits and vegetables should be stored in a cool, dark place for a minimum time to prevent loss of nutrients.

Choice of fruit and vegetables

Value range Luxury Fair-trade Organic

How are fruit and veg classified? What are fruit and veg used for?

Cont… Classification:

Soft fruits- berries Citrus fruits- oranges and lemons Stone fruits- plums, apricots Fleshy fruits- apple, pear and banana Vine fruits- grapes

Fruit vegetables- aubergine, tomato and cucumber Legumes- pea, bean and lentil Flower vegetables- broccoli, cauliflower Leafy vegetables- spinach and cabbage Stem vegetables- asparagus Fungi- mushroom Bulbs- onion and garlic Roots- beetroot and swede

Cont.. Uses of fruits and vegetables: Addition of colour- chlorophyll- green, carotenoids- orange, anthocyanin's-

purples. Addition of flavour- sweet and sour Addition of texture- contain different amounts of water and fibre which

accounts for the different textures. Setting- fruit contains pectin which when mixed with an acid and sugar, helps

mixture to set. I.e. Jam. Eating raw- retention of colour and nutrients Cooking- stewing, boiling, steaming, frying, baking. Processing- drying, canning and freezing. Pickling- beetroot, cabbage and onions.

Activity 4.31, 4.32, 4.33, 4.34, 4.35

Recap of fruit and vegetables. List the main nutrients found in fruit and vegetables. Which vegetable is highest in fat? Which fruit is highest in

potassium? Give 3 categories of fruit, and 3 categories of veg. What nutrients are fruits and vegetables high in that can

prevent CHD? Fruits and vegetables contribute colour to a meal/dish, what

colours are the following: Anthocyanins- Chlorophyll- Caroteinoids- What does fruit contain that can be used to set jam? Name the different methods of cooking fruit and vegetables How can fruit and vegetables be preserved?

PRACTICALS

Make a fruit dessert- flan, cheesecake Make a main course vegetable dish- stir

fry, lasagne.

Revision of food commodities 1) what proteins are in the muscle fibres of meat? 2) what is the nutritional value of meat? 3) how should meat be stored? 4) what is the nutritional value of fish? 5) what does the connective tissue in fish convert to in cooking? 6) what are cephalopods? 7) what is the nutritional value of an egg? 8) list the main uses of eggs? 9) what is the nutritional value of dairy products? 10) what are alternative proteins also know as? Give some examples. 11) name 6 different cereals 12) what is the difference between saturated and unsaturated fats?

SUGAR In the UK, sugar comes from sugar beet. This is grown in the UK and

Europe or imported from tropical climates. The sugar is extracted, refined and crystallised into a variety of brown and white forms.

Consuming too much sugar can increase the risk of tooth decay and obesity.

Sugar is a valuable source of energy.

Types of sugar: Refined white sugar- caster, granulated, icing sugar. Partially refined sugar- Demerara. Unrefined sugar- soft brown. Syrups and treacle's- golden syrup, treacle.

Cont.. Uses of sugar:

Aeration- when fat and sugar are creamed together. Bulking- sugar is used to increase a products size, volume or weight-

ice-cream, jam and cakes. Coating- sugar can be used to make fondant icing. Colour- sugar has a browning effect on the surface of bakery products. Gelling- jam making- presence of pectin, acid and sugar in correct

amounts forms a gel. Moisture retention- sugar has water attracting properties. Preservation- high concentrations of sugar helps stop growth of micro-

organisms. Stabilising- sugar stabilises egg white foam.

SWEETNERS Intense- much sweeter than sucrose. (Aspartame- E951) Bulk- much the same as sucrose. (Sorbitol)

Uses:

Allow diabetics to enjoy an alternative to sugar Tablet sweeteners are added to hot drinks. Powder sweeteners are sprinkled onto food and are used to

make confectionary. Canderel and Splenda are examples of sweeteners that work

well in cooking.

Performance characteristics of ingredients

FUNCTIONS OFINGREDIENTS

Chemical

Physical

Nutritional

Sensory

flavour

colour texture

smell

Maillard reaction

Dextrinisation

CO2 production Bread

Kneading and cooking

Adds fibre

Adds fatAdds vitamins

Adds protein

Foaming

Egg white

Meringue

Emulsification

Stable unstable

Setting/coagulation

Eggs- fried

Gluten formation

gelatinisation

sauces

shortening

caramelisation

Melting sugarpastry

Browning/ chemicalreaction

Performance characteristics of eggs and flour. Eggs and flour offer many useful performance characteristics that can be

incorporated into food products. Eggs have many performance characteristics- they coagulate which

means they set, and the proteins denature, they bind, coat, thicken, enrich and glaze.

They can be whisked to create foams and aerate mixture. They are also emulsifiers. Certain ingredients can collapse foams however- experimental work will show this. Sheets in file.

PAGE 116-119- complete notes on coagulation, foam formation and emulsification.

EXPERIMENTAL WORK- 4.41, 4.43. Foaming- what factors affect foam formation? How long they are whisked for, if any yolk gets in, addition of other

ingredients- acid, sugar

Behaviour changes and performance characteristics of ingredients. What do the following mean? Gelatinisation- starch absorbs liquid and thickens. Retro gradation- staling of starch in baked goods. Maillard reaction- chemical reaction between protein and starches in

bread. Browning. Starch is converted into dextrin and this is called dextrinisation.

Gluten formation- Gliadin and Glutenin (both proteins) form gluten in flour.

Beating- between butter and sugar in cake making- adds air. Whisking- foaming of egg white in mousse, and whole egg in Swiss roll. Shortening- texture given to butter and flour when rubbed together-

shortbread/pastry Kneading- bread dough to add air Heating (fat, protein, sugar)- fat melts, protein denatures and sugar

caramelises. Activity 4.44/ exam questions 4 and 5

Performance characteristics of eggs. Factors affecting foam formation:

Salt, sugar, fat, acids.

Emulsification-

An emulsion is formed when one liquid is dispersed in small droplets into a second liquid with which it will not mix. The most common emulsion is oil in water, emulsions cannot exist without an emulsifying agent- egg yolk is an example of this. The egg yolk contains LECITHIN which has a hydrophobic (water hating) and hydrophilic (water loving) component. This property is used in mayonnaise.

Performance characteristics of flour. Gelatinisation; This occurs when starch- flour is added to a liquid and heated- ie

sauce making by blending method. Starch granules absorb liquid and thicken when heated.

Amylose and Amylopectin are starches which behave differently in cooking- Amylose causes sauces and fillings to thicken and turn cloudy when cooked, Amylopectin produces a clear gel when it thickens and has same thickness when hot or cold.

Retro gradation; Staling of starch based goods.

Continued…. The proteins in flour- gliadin and glutenin produce gluten

when kneaded in bread giving elasticity and strength and shape to baked products.

Factors affecting gluten formation:

Fat coats the flour in a mixture and this prevents absorption of water. This action reduces the amount of gluten that develops in the baked product. Sugar also reduces the amount of gluten in a product because it competes for water.

Food additives Types- natural, nature identical, artificial. What do these mean- use

book? Food additives are thoroughly tested before use in EU, and given an

E number to show they are safe.

General Functions- prevent food spoilage, enhance flavour, restore a nutrient after processing, maintain consistency, reduce wastage.

Types are Preservatives, Antioxidants, Food colourings, Flavour enhancers, Emulsifiers and Stabilisers and Nutritional additives

Find out more about the different food additives. Explain each one. Activity 4.45

Additives

Natural- these are obtained from natural sources i.e. the purple colour extracted from beetroot is used to colour sweets.

Nature identical- these are synthetic copies of substances that naturally occur. The natural source may be expensive, so an identical additive is manufactured in a laboratory.

Artificial- these do not occur naturally, and are man-made.

Product development

Design, development and production of new food products. Product development is crucial in the food industry. ACTIVITY

5.1, 5.2. There are various stages in developing a new food product:

Stage 1- identifying a need- concept generation, understanding consumer needs, identifying intended target market, investigating the market – market research( Quantitative research- factual data, Qualitative- in depth), Disassembly.

Stage 2- concept screening- drawing up ideas and select and reject, design specification written.

Stage 3- development and testing, prototype, product testing, writing manufacturing specification.

Stage 4- production methods- batch, mass, safety and quality control- HACCP.

Continued… Stage 5- packaging and labelling Stage 6- advertising- marketing plan- price, place,

product, promotion. Types of marketing: Above the line- involve purchasing time and space in

the media; GENERAL TV, newspapers, supermarkets magazine

Below the line- PERSONAL- price promotions, money off coupons, link promotions, product placement, demonstrations. Activity 5.5

Stage 7- launch- page 141

Design, development and production costs; Design and development- Product development team do: Market research- surveys, interviews Use IT- CAD/CAM-design ideas Product testing- development and evaluation of prototypes Trialling- sampling Design Packaging- target market, storage conditions, cost. COSTS: Raw materials and labour- ingredients, training for staff Factory and machinery-production team, renting equipment, fixed costs

are maintenance, salaries and insurance, variable costs are ingredients and packaging.

Distribution-refrigerated storage, transportation, food miles, imports. Marketing-advertising campaigns, personal selling, packaging. Advertising-merchandising- at point of sale, influencing a consumer to

buy. Pricing-correctly in a competitive market.

Influences on price Costs of production and manufacture, demand for a

product and markets trends, consumer expectations, target market.

Pricing strategies- cost based pricing is based on production costs, the price is set by working out cost of producing item and adding a fixed mark up for the profit.

Market based pricing is based on the market and consumer requirements.

Competition based pricing is known as market or rate pricing and involves charging the same as competitors or the market leader.

Importance of sensory testing:

Evaluate new and established food products. Analyses food products for improvements. Establish consumer response to a product Ensure that a product meets its original

specification Assess quality control Maintain product quality Assess shelf life.

Sensory analysis tests: Find out what all these cover: Hedonic ranking Difference tests Grading tests

Activity 5.7

Risk assessment in the food industry: HACCP 147-152 identify the 7 stages involved and

explain them. Activity 5.9 and 5.10

Risk assessment in the food industry-HACCP- seven stages HACCP is a legal requirement for all food businesses. Stage 1- identify the hazard- physical, chemical or

biological. Stage 2- identify critical control points- must be carried

out to prevent hazard from occurring. Stage 3- critical limits- temps Stage 4- monitor critical limits- colour coded system/ food

probe for temp. checking. Stage 5- establish corrective actions if necessary, i.e..

Clean equipment again if it is dirty. Stage 6- record system- temp logs, cleaning schedules Stage 7- verify the system- checking

Contamination Physical- foreign bodies entering food- i.e. hair and nails.

Chemical- traces of chemicals entering food- bleach, cleaning agents.

Biological- micro-organisms can contaminate food- moulds, fungi.

Food packaging: Why package?

Protection of food product Containment of food product Barrier protection to water vapour, air and dust. Information about product Convenience- the design can assist handling. Marketing- packaging used can encourage sales Security, so food product is not tampered with.

Find out advantages and disadvantages of each material; plastic, paper and cardboard, metals and foils, glass. 153-159

Find out the following:

Tetra packs- uses paper, plastic and foil- i.e. orange juice carton.

Aseptic packaging- involves filling a sterilised pouch with a sterile food, gives an extended shelf life. Uses paper, plastic and aluminium foil.

MAP- modified atmosphere packaging- involves the use of 3 gases- CO2, O2 and nitrogen. Food products are sealed inside packs containing one or all of these gases.

Vacuum packing- air is sucked out and packaged sealed to improve shelf life.

Labelling

Find out about the food labelling regulations, 1996. (page 160)

The following information must appear on a food label by law: Name of food Weight/volume Ingredients in descending order Date and storage conditions Preparation instructions Name and address of manufacturer Batch number, in case recalled by manufacturer Nutritional info. GDA’s- Guideline Daily Amounts for nutrients.

What is traffic light labelling?- these show whether the food has high, medium or low amounts of fat, sugar and salt. A red light indicates that the product is high in one or more of fat etc.., Amber indicates it is neither high or low. Green is low in all.

Traffic light labelling

What is traffic light labelling? These show whether the food has high,

medium or low amounts of fat, sugar and salt. A red light indicates that the product is high in one or more of fat etc.., Amber indicates it is neither high or low. Green is low in all.

Developments in the food industry

Developments in the food industry

By the end of the topic, you should understand:

Changes in the UK food industry Factors that affect food production Developments in product ranges Environmental and moral concerns

affecting food production

Developments in the food industry. Current issues: Supply and availability of food has changed- WW2; rationing- food was

in short supply, anything you want now, anytime. Advancements now in importing, B2B e commerce- retailer and supplier well linked, EPOS- track when stock is running down, Self scan, Bar-coding, Radio frequency identification tags on food to trace where they are from.

Globalisation has occurred- importing all over the world leads to food miles- how far your food has travelled is a big concern to many people now.

Food security- equal access to food, no rationing now. Product ranges also assist here- cater for all target markets.

Price of food- has gone up due to increasing price of oil- needed for importing- lorry, plane, ship and food production methods.

Health and nutrition- increases in obesity- dieting products now available. Food industry has addressed this.

Continued…. Food safety and quality- FSA looks at protecting the public from

unsafe food. Food poisoning outbreaks picked up. In supermarkets now- electronic thermometers frequently assess temperature. Advancements now in packaging to preserve shelf life of food products- MAP, freeze drying, Aseptic packaging.

Food chain and the environment- global warming and climate change have increased causing less crops being grown. In order to protect the environment we need to use local produce to prevent importing which causes pollution, use Fair Trade where possible, recycle our waste, buy products with less packaging, use up old food where possible- ie old bread- breadcrumbs. Compost old food waste. Take own shopping bags to grocery store.

Major factors affecting food production. Find out more about the following, use text books. Page 168-179

Environmental and moral concerns- Sourcing food, organic food, animal welfare, fair-trade, food waste.

Social changes – disposable income, changing nature of family, patterns of work, changes in eating patterns, leisure patterns, population movement, food access and media.

Technological change-packaging- MAP, vacuum packing, SMART ingredients,ICT,food processing methods.

Food safety- food scares, EU food safety policy, Biotechnology and GM, food sensitivity (allergies)

Health issues- labelling, legislation, demand for healthy products, functional foods.

ACTIVITY 6.2

Product range developments Growth of ready meals and convenience foods-

social change, more reliance on them now. Supermarket own brands- value for money. Indulgence products- expanding market, seen as

treats. Provenance (where it is from) of the food product-

consumers want to see more local produce or where it is sourced.

Food intolerance products- food allergy has increased. Healthier food products- consumer concern over

obesity.

Changes in availability and supply Climate change- poor weather, hot climates all the time cause less crops

to grow- rice, wheat, maize etc.. Demand for bio fuels has increased- crop fields are used now to grow

crops that can be converted into bio fuels, also food waste is burnt to produce bio-fuels which are sustainable and better for the environment unlike fossil fuels. Bio-fuels are needed for energy.

Price of oil has increased- needed in production and processing of food products- importing, delivery of food to supermarkets.

Common Agricultural Policy- set up after WW2, to provide a fair standard of living for European farmers, to give reasonable prices for farm products and to ensure fair standard of living for farmers.

Over-fishing- decline in fish stocks due to over fishing. Sustainable fishing policies are required across Europe.

European legislation- aims to make the food we eat safer, and environmentally friendly- restrictions on pesticides and additives.

Emerging economies- rapid growth and industrialisation- Brazil, China represent potential markets for products.

EXAM QUESTIONS.

Bio fuels

Bio fuels are any liquid, solid or gaseous fuels produced from organic matter. The extensive range of organic materials used for bio fuel production includes starch and sugary plants such as corn, wheat or sugar cane; oily plants such as rape seed, soya beans or vegetable oils and animal fats; wood and straw; algae and organic waste and others