Food Technology Overview

Proteins

Fresh fish is a source of protein

Proteins assist with growth and repair of the body.

Proteins are found in animal products like meat, fish, cheese, milk and eggs. Vegetable sources include soya-bean products, pulses and nuts.

Carbohydrates

Carbohydrates are needed to give the body energy. There are two types of carbohydrate - starch and sugar.

• Starch is found in cereals, cornflour, potatoes, pasta and flour.

• Sugar is found in fruit, vegetables, honey, milk and malt products.

Fats

Fats help to provide concentrated sources of energy and help to insulate the body in cold weather. There are two main types.

• Saturated fats are usually obtained from animal sources, for example butter and lard. The exceptions are coconut and palm oils.

• Polyunsaturated fats come from vegetable sources, such as sunflower oil

Calcium

Calcium is needed for the growth of healthy teeth and bones. Sources of calcium include milk, cheese, eggs, wholegrain cereals, green vegetables, bread and tofu.

Iron

Iron is needed for the formation of red blood cells. Sources of iron include red meat, green vegetables, eggs, lentils and bread.

Vitamin A

• - good vision

• - healthy skin

• - growth

• - green and yellow vegetables

• - dairy product

Vitamin B12

• - red blood cells

• - meat

• - milk

• - yeast

Vitamin C

• - healthy skin

• - protects cells

• - helps absorb iron

• - fruit

• - vegetables

• - oily fish

• Vitamin B (thiamin, riboflavin and niacin)

• - release of energy from foods

• - healthy skin

• - breads

• - milk

• - eggs

Vitamin D

• - helps absorb calcium

• - strong teeth and bones

• - margarine

Starch

• thickens a liquid by forming a suspension such as a sauce

• forms a gel when the suspension is heated, like adding cornflour to a custard powder and milk mix

Sugar

• flavours by sweetening

• colours by caramelising when heated

• aerates when beaten with a fat such as in a cake mix

• Binding uses fats, eggs, cereals and flour to bind ingredients. For example, egg is used to bind together a biscuit mixture.

• Bulking forms the main structure of a food product, such as flour in biscuits and cakes.

• Enrobing means coating a food with another ingredient, for example, dipping fish in beaten egg and then breadcrumbs.

• Enriching is the addition of an ingredient to improve the quality. Nutrients are sometimes added to increase nutritional value.

• Fermentation uses yeast to convert carbohydrates into alcohol and carbon dioxide. In bread making, yeast is added to flour and water causing the dough to rise.

• Flavouring can be savoury, like herbs and spices, or sweet, like sugar or sweeteners. Sugar helps to soften the sharp taste of grapefruit.

• Shortening uses of oils and fats to reduce the development of gluten in pastry to make the dough less stretchy.

• Stabilising helps food keep its structure. Eggs and flour are used for stabilising.

• Setting means using ingredients to make foods firm, such as gelatine to set cold desserts.

• Solution is when one substance is dissolve in another one, for example when sugar is dissolved in water we get a sugar solution.

• Colloid is a general term for when two substances are mixed together. For example milk has a colloidal structure, because it is made from microscopic drops of fat dispersed in a water-based liquid.

• Emulsion is when two unblendable liquids are mixed together, for example, oil and vinegar. An emulsifier like egg yolk is needed to stop them from separating. Emulsions are a particular type of colloid. Mayonnaise is an emulsion.

• Foam is when air bubbles are incorporated into a liquid, such as in whipped cream and meringue

• Gel contains a small amount of a solid in a large amount of liquid. A small amount of gelatine can set a large amount of liquid.

• Suspension is when a solid is held in a liquid. The solid may sink if the mixture is not stirred. Flour (solid) is suspended in milk (liquid) when making a cheese sauce.

Proteins

• can coagulate which is when a liquid becomes firmer, for example when an egg is heated

• can aerate a mixture, like whisking egg whites in a meringue mix

Fats

• shortens pastry (makes it more crumbly) by making it less stretchy

• can act as an emulsifying agent to stop two liquids from separating

• moistens a baked mixture such as a cake

Chilling

Dairy produce, cooked foods and raw ingredients should be kept at a temperature between 0°C and 5°C. This will slow the growth of microorganisms, but won't stop it.

Freezing

Meats, vegetables and ready meals can be frozen. Freezing maintains high standards of freshness and safety. Freezers store products at -18°C or below. Freezing does not kill microorganisms, but will keep them dormant until the food is unfrozen.

Reheating foods

Food must be reheated to at least 72°C to avoid the risk of food poisoning. Leftovers should be disposed of quickly.

The manufacturing specification lists information a manufacturer needs to produce the product. The specification records the stages of the production process, with details of all the characteristics (shape, size, texture, colour, flavour etc) required in the final product.

It also lists where standard components can be used. A standard component is a pre-prepared ingredient used in the production of a food product, like pizza bases or ready-made sauces.

Quality control checks will normally include:

• weight checks to make sure the product is the required weight
• visual checks to make sure it looks the way it should
• temperature checks to make sure it is being kept at an appropriate temperature
• pH checks to make sure the food has the correct acidity/alkalinity
• microbiological checks to make sure bacteria are not at harmful levels
• chemical checks to guard against chemical contamination
• metal checks to guard against contamination by metals (usually at the packing stage, using a metal detector)
• organoleptic checks to check flavour, texture and aroma by sampling the food product

MaterialAdvantagesDisadvantagesUses Glass

• - reusable
• - heat-resistant
• - recyclable
• - keeps shape
• - low cost

• - fragile
• - safety issues
• - heavy

• - baby foods
• - salad cream
• - pickles

Metal

• - recyclable
• - lightweight
• - impermeable
• - withstands heat processing

• - may react with food

• - soup cans
• - take-away containers
• - bottle tops

Card/paper

• - easy to print on
• - cheap to produce
• - biodegradable
• - recyclable
• - can be moulded
• - can be coated
• - lightweight

• - not water-resistant
• - easily damaged

• - fruit-juice cartons
• - egg boxes

Types of Packaging

• Primary packaging is seen at the point of sale. It needs to contain and protect the food product, as well as display it and provide information.
• Secondary packaging is the middle layer of packaging - for example a cardboard box with a number of identical products inside.
• Transit packaging is the outer container that allows easier handling during transfer between factory, distribution centres and retailers

Plastics

Plastics are widely used in food packaging because they are:

• versatile - plastics can be flexible or rigid, and can be moulded into shapes.
• resistant to acids and other chemicals
• easy to print on
• lightweight
• cheap to produce

(Note: not all plastics have all the above qualities.)

Modified-Atmosphere Packaging (MAP)

Air in a plastic container can be modified to prolong shelf life and slow down colour deterioration.

MAP is used to package:

• cold meats
• smoked fish
• cheeses
• salads
• fresh pasta

These are the items on the label that are required by law.

• manufacturer's name and contact details
• name of the product
• description of the product
• weight (some foods are exempt, for example bread)
• ingredients (listed in descending order of weight)
• cooking/heating instructions
• storage instructions
• shelf life
• place of origin
• allergy information

The following items are not legal requirements, but are nevertheless good practice and often included on packaging:

• illustration of product
• price
• nutritional values of the product
• customer guarantee
• the batch-code and bar-code numbers
• opening instructions

• Fair trade food production aims to provide fair prices and better working conditions for farmers and farm workers.
• Farm assured means that the farms and food companies meet high standards of food safety and hygiene, animal welfare and environmental protection.
• Food miles means the distance that food travels from where it is grown to where it is bought. This is an environmental concern because of the CO₂ emissions from transport.
• Free range is a method of farming where animals are allowed to roam freely.
• Genetically modified food is grown with genetic manipulation technology. Some people consider this a risk to the environment and choose GM-free products.
• Organic foods have been grown without the use of chemical fertilisers or pesticides.
• Seasonal foods means foods that are in season. Choosing these reduces food miles
• Sustainability is food production that aims to preserve the world's natural resources for future generations.

Fibre or non starch polysaccharide (NSP) is not absorbed by the body but is needed to help maintain a healthy digestive system. There are two types of fibre:

Soluble fibre - found in fruit, vegetables, pulses and oats. It helps to reduce blood cholesterol.

Insoluble fibre - found in cereal such as bread and pasta. It helps to stimulate the digestive system.

An unbalanced diet includes too much or too little of the recommended food groups, this can lead to:

• coronary heart disease
• high blood pressure
• obesity
• tooth decay
• diabetes

• One-off production is when a single product is made, for example a designer wedding cake. This is classed as a luxury food item.
• Batch production involves making of a set number of identical products. Typically batch production is used in a bakery, where a certain number of different types of loaves will be made every morning.
• Mass production is used to make foods on a large scale. The production line involves repetitive tasks so machines are often used. This saves time and helps lower the cost of production.
• Continuous-flow production is a high-volume production method where machines run 24 hours a day. It is often used to produce milk and packet pizzas.

CAM is used to:

• monitor temperature, monitor weight, check pH, control conveyor belt speed, monitor quantities of ingredients

Advantages

• more consistent results
• reduces labour costs
• improves accuracy, reducing waste
• faster for high-volume production
• improved saftey and hygiene
• easier monitoring

Disadvantages

• expensive to set up
• needs skilled operators
• can be slower for one-off or low-volume production

Advantages of using standard components

• ensures consistency
• saves time and effort
• less skill required by staff
• less specialist equipment needed
• can reduce costs
• components bought in bulk
• reduces risk - high risk foods prepared elsewhere

Disadvantages of using standard components

• less reliable - one manufacturer depends on another
• components can be more expensive
• sensory qualities may not be as good as fresh ingredients
• large amount of storage space
• time needed for ordering and delivery

• Biological hazard - foods become dangerously infected by bacteria which might lead to food poisoning. Symptoms of food poisoning can include diarrhoea, vomiting, headaches and fever.
• Physical hazard - foreign materials can cause injury to the consumer. These could come from metal or plastic from factory machinery, or natural hazards like bones in fish.
• Chemical hazard - potentially dangerous chemicals like cleaning fluids or pesticides contaminate food. These could cause severe illness.

Critical control points

Critical control points (CCPs) are pre-determined checks that take place at specified points in the food production or preparation process. They include:

• temperatures, using probes and thermometers
• cooking times
• ensuring food is handled correctly