Food Tech

What are the water soluble vitamins?

Vitamin C

B group vitamins

Folic acid

What is the function of vitamin C/ Ascorbic acid ?

Needed for healthy connective tissue

Helps wounds heal

Helps in the absorption of iron

Is an antioxidant

What are the sources of vitamin C ?

Citrus foods (lemons,limes,oranges,grapefruit etc)

Blackcurrents

Red/green peppers

What happens when someone has a deficiency of vitamin C?

They get scurvy.

This causes swollen gums,joint pain and wounds fail to heal.

What happens when someone has an excess of vitamin C?

Can cause stomach pain and diarrhoea.

Ways of preventing loss of water soluble vitamins when buying and storing foods.

• Keep the foods cool and dry

• Store airtight

• Keep milk and grains away from strong light

• Limit surface area

• Cooking/eating as soon as possible

• Buy the freshest vegetables

Ways of preventing loss of water soluble vitamins when cooking food.

• Steam foods,don’t boil

• Keep skins where possible

• Avoid continuous reheating

• Use minimal amount of cooking

• Serve raw where possible

• If boiled,use water to create soup

What is the function of calcium?

• Maintains normal bones and teeth

• allows normal blood clotting

• controls muscle contractions including the heart beating

What are the sources of calcium?

• Milk/dairy products

• Edible soft bones of fish (canned salmon)

• Green leafy vegetables

• Fortified soya bean products

• Bread (fortified in UK)

How are calcium levels regulated?

By hormones like vitamin D.

What happens when calcium intake is too low?

Calcium is withdrawn from bones.

This leads to low bone density which can cause osteoporosis.

This may be caused by a lack in vitamin D which is common in teenage girls.

What is Iron needed for?

• The formation of haemoglobin in red blood cells

• Transport of oxygen around the body

• Function of the immune system

• Normal cognitive function

• Reduction of tiredness and fatigue

• Cell division

What are the two types of iron?

Haem iron.From animal source.This is readily absorbed into the body.

Non-haem iron.From plant sources,fortified foods and supplements.Vitamin C helps the absorption.

What are the sources of Iron?

• Cereals

• Vegetables

• Nuts

• Egg

• Fish

• Meat

What is a lack of Iron called?

Iron deficiency anaemia.

It is the most common nutrient deficiency. Menstruating women are at a higher risk for this.

Which nutrients interact with others?

• Vitamins A,C and E

• Calcium,Phosphorus and Fluoride

• Calcium and Vitamin D

• Iron and Vitamin C

• Carbohydrates and the B vitamins

Vegan

someone who chooses not to eat anything made from animals or fish, including eggs, milk and cheese

Nutritional analysis

The process of determining the nutritional value of foods

Target group

The primary group of people that something,normally an advertising campaign,is designed to appeal to.

Dietary Dairy

A daily log of what you eat or drink each day

Food tables

Collections of data on the nutritional contents of food.

Cardiovascular Disease and Strokes

Cardiovascular disease is when blood flow is restricted because of fatty deposits inside an artery. .Strokes are when blood flow is cut off to the brain or when a blood vessel in the brain bursts.

Obesity

Abnormal or excessive fat accumulation

What happens to a water soluble vitamin like B group or C when cooked?

They leech into the cooking water and are destroyed when exposed to heat for a long time.

What happens to a water soluble mineral like calcium or Iron when cooked?

They are lost when fat is drained

What happens to a fat soluble vitamin like A,D,E or K when cooked?

They leech into the cooking water.

Shortening

The fat coats the flour particles and prevents them from absorbing water.This reduces the gluten development,which would cause the dough to become elastic.

Used in shortcrust pastry,biscuits and shortbread.

Aeration

This is achieved by creaming a fat with caster sugar.

Small bubbles of air are incorporated and form a stable foam which can be baked to give the springy texture.

Used in creamed cakes.

Plasticity

This describes the ability of a solid fat to soften over a range of temperatures.Fats do not melt at fixed temps but at a range.

This plasticity is due to the mixture of triglycerides,each with its own melting point.

What is an emulsifier?

A mix of two parts,Hydrophilic and hydrophobic.

The two types of emulsions

1. Oil in water emulsion forms when the amount of water is greater than the amount of oil.Tiny droplets of oil are spread throughout the water.E.g milk

2. Water in oil emulsions forms when the amount of oil is greater than the amount of water.Tiny droplets of water are spread throughout the oil.E.g Butter

Making butter

Fat globules ‘smash’ together in churning which causes the outer layer to break open these two fat globules are now combined as a larger particle.As you continue churning the fat particles become so large that they come together in a large mass.

Emulsion

The forced mixture of two substances (oil and water) that would normally separate from each other,

Denaturation

The change in structure of a protein. The long chain of amino acids that make up a protein unfold from their coiled state.

Methods to denature proteins

1. adding acid

2. mechanical action

3. heating

Curdling

This is when the protein in milk is denatured by acid.

The milk then develops a slightly lumpy appearance as all the protein in the milk has clumped together.

Coagulation

This is the setting of protein brought about by heat and is IRREVERSIBLE.

coagulation in different foods

• Heated protein foods will coagulate in different ways

• Meat protein will shrink when they coagulate(heating meat in a liquid will change the structure of the muscle fibres) The protein collagen will change to gelatin.

• Egg whits become solid and turn white as they coagulate at 60C but egg yolk becomes solid at 70C

• The protein in wheat is called and as this sets it gives the food their firm structure.

• The milk proteins will coagulate and form skin on heated milk

• Syneresis results from the over-coagulation of egg protein. Water is pushed out of the eggs.

Gluten formation

Gluten is a protein made from two proteins: GLUTENIN and GLIADIN

Glutenin gives the dough elasticity and Gliadin binds the dough together.When water is added gluten is formed.

As the dough is kneaded gluten continues to form, creating a framework in the bread dough which traps the CO2 from yeast.

Where does protein come from?

• meat

• eggs

• nuts

• poultry

• fish

• beans

• lentil

• dairy

• vegetables

• soy beans

Why do we need protein?

• helps body grow and repair

• forms structural and functional elements of body cells

• growth in muscle mass

• provides energy

• involved in various metabolic reactions

Examples of protein complementation

• rice and peas

• beans on toast

• hummus and pita

• bean chilli and rice

Recommended protein intake.

RNI is set at 0.75g of protein per kg of body weight per day as an adult.

The average male should have 56g of protein per day

The average female should have 45g of protein per day.

Kwashiorkor

This is a disease in children when they are weaned off milk to a diet low in protien.It is a form of severe malnutrition.

Meat alternatives - Soya

Made from: beans,flour,water and flavours

Made into: Tofu and TVP

Nutrition: Provides protein

Meat alternatives - Quorn

Made from: micro-organisms and egg whites

Made into: Chicken fillets/meat substitutes

Nutrition:

• High in HBV protein

• High in fibre

• low in fat

• low in vitamins and minerals,needs to be fortified

Protein sparer

a substance in the diet that stops the use of protein for energy

Dietary fibre

Polysaccharides found in cell walls of veg,fruit,pulses and cereal grains.

Unlike other types of carbohydrates,these are not absorbed in the small intestine to provide energy and instead is digested in the large bowel by bacteria.

Sources of Fibre

• wholegrain cereals and cereal products

• pulses

• fruit and veg

• nuts and seeds

• brown rice

• potatoes

What happens when you have a lack of dietary fibre?

• constipation

• IBS

• diverticulitis

• heart disease

• some cancers

• blood sugar fluctuations

• a rise in cholesterol levels

• immune system may be compromised

What is the difference between insoluble and soluble fibre?

Soluble fibres dissolve in water.

Soluble fibres include plant pectin and gums.

Soluble fibre creates a gel once it dissolves to improve digestion.

In soluble doesn’t.

In soluble fibres includes plant cellulose and hemicellulose.

Insoluble fibre attracts water to your stool,causing less strain on your bowel.

LDL

Low density lipo-protein.This is ‘bad’ cholesterol which builds up and eventually clogs up arteries.

HDL

High density lipo-protein.This is ‘good’ cholesterol which absorbs cholesterol in the blood and carries it back to the liver.

Where would you place raw foods and eggs in the fridge?

On the bottom shelf above the drawers.

This is so no juices drip and contaminate other foods.

Where would you place the cooked meat in the fridge?

On the top shelf.

What are some tips when using a fridge?

1. Wrap foods that aren’t already

2. The top shelf is most likely the warmest

3. Door shelves are warmer than other parts

4. Food should be refrigerated for short amounts of time

5. Let hot foods cool before putting them in the fridge

6. Try not to open and close the fridge door a lot.

7. Fridges should be cleaned out regularly

8. Keep raw meat covered and on the bottom shelf

9. Drinks and milk should be kept in the door.

What are some personal hygiene rules for the kitchen?

• Hair up

• Wash hands

• Sleeves rolled up

• Don’t touch your face

• Cover cuts

• Gloves,mask

• Hair/beard net

• Apron

• No jewellery

How do you use a food thermometer probe?

1. Clean and disinfect the probe before use

2. Insert the probe to the centre or thickest part of the food

3. Wait a few seconds for the display to stabilise before taking a reading

4. Read the temperature

5. Check the food has reached 75 C

6. Clean and disinfect the probe after use

What are some food safety points when buying food?

• Make sure foods are in date

• Buy cold foods when a fridge/freezer is available

• Keep high risk foods out of the danger zone for as short as possible.

How can we reduce the amount of food waste?

• Planning meals before buying

• Cooking the correct quantities

• Storing foods correctly

• Picking less attractive foods

• Reuse leftovers

• Only buy foods you know will be eaten

How can manufacturers reduce the amount of food waste?

• Make date labels clearer

• Adding storage advice

• Produce resealable packaging

What is the impact of food packaging?

• Most isn’t reused

• Takes a lot of energy to break down

• Ends up in land fill and releases many pollutants

What is food miles?

The distance food travels from field to plate

What are the pros of buying locally produced foods?

• Supports local farmers/businesses

• Generally fresher

• Sometimes better nutrition

• Generally cheaper

What are the cons of buying locally produced foods?

• Isn’t necessarily organic

• Produce can only be grown at certain times of the year

• Less variety available

What is organic farming?

Producing crops with no artificial chemicals

What are the pros of organic farming?

• No GM crops

• Use of natural fertiliser

• Restricts use of chemicals

• Taste nicer

• Looks after wildlife

What are the cons of organic farming?

• Expensive

• Less available in shops

• Limited choices

• Same nutrients

• Short shelf life

What is carbon footprint?

A measure of the impact the product or an individual has on the environment,in terms of the amount of greenhouse gases they produce.

What is a Lacto-vegetarian?

Someone who doesn't eat meat and eggs

What is a Lacto-ovo-vegetarian?

Someone who eats vegetables,eggs and dairy products but not meat.

What is a vegan?

Someone who chooses not to eat anything made from animals or fish, including eggs, milk and cheese.

What is protein complementation?

Different foods have different amounts and types of amino acids.

Vegans and vegetarians can get all essential amino acids by combining two LBVs.

What are the causes of Cardiovascular disease and Strokes?

• Unhealthy diet

• Lack of Physical activity

• Tobacco use

• Alcohol use

• High cholesterol

What are the causes for Obesity?

• Unhealthy diet

• Little to no exercise

• Genetics

• Health conditions

• Stress/mental health problems

what are the sources of vitamin D?

• milk and butter

• liver

• oily fish

• eggs

• fortified breakfast cereals

What is vitamin D needed for?

• developing and maintaining bones and teeth

• healing broken bones

• helping the body absorb calcium

• preventing bone diseases

what happens when a person is vitamin D defficient?

It can result in rickets in babies and toddlers.

What groups are at risk for a vitamin D deficiency?

• pregnant and breastfeeding women

• babies and young children under 5

• people who are not exposed to the sun often

• people who have darker skin

What is the DRV for vitamin D?

10 micrograms.

Describe mayonnaise as an emulsion

(what it's made of etc)

It is made of oil,vinegar and eggs.

Egg yolk contains lecithin, an emulsifier, as it attracts both oil and water so binds the ingredients together.

Lemon juice helps to stabilise the mixture.

What is sensory evaluation?

It is judging the different sensory qualities, (senses).

Why conduct sensory analysis?

• to ensure food meets customer expectations

• to ensure that any changes to the product (sugar free etc) remain acceptable and consumers still like the product

• to guarantee that food products remain consistent.

• to compare food products with competitors

• to ensure food products meet the original specification

• to monitor the quality and shelf life of food products over time

What are the different sensory analysis tests?

• paired preference test

• hedonic ranking

• triangle test

• ranking test

• rating test

• profiling

What is the paired preference test?

A person is given two samples and is asked which they prefer.

What is the hedonic ranking test?

This is a type of preference test that finds out if people like or dislike a product/s.

They rank the samples on how much they like them.

What is the triangle test?

This is used to detect differences in two samples, a person is given three sample, two are the same, and they have to find the odd-one out.

What is the ranking test?

Looks at a particular sensory property in a number of samples.

What is the rating test?

Allows people to rate different sensory properties of a food.

What is profiling?

Used to get a detailed description of the appearance, taste and texture.

How do you create a fair testing environment?

• distractions including smells should be removed

• lighting should be controlled and coloured lighting should be used if there are visual differences between samples

• seating should isolate testers

• water should be provided to allow the sampler to cleanse between samples