Diet, Nutrition & Food Tests

List the 7 different food groups

• Carbohydrates

• Protein

• Fibre

• Vitamins

• Minerals

• Fats

• Water

Determine the main function of Carbohydrates and its food sources

→ Carbohydrates are the main source of energy for the body that are broken down in respiration to be used.

• Rice

• Grains

• Pasta

• Bread

What is the main function of protein and its food sources?

→ Protein is responsible for the growth and repair of muscles in the body

• Fish

• Poultry

• Eggs

• Legumes

Determine the main function of fats and its food sources?

→ Fat is a store of energy in the body that can also act as an insulator under the skin

• Butter

• Oil

• Nuts

What are the main functions of Specific vitamins in the body and their sources?

1) Vitamin C = makes collagen for the hair,skin, nails and gums

• Citrus Fruits

• Vegetables

2) Vitamin D = helps with the absorption of calcium in the body

• oily fish

What are the function of specific minerals in the body and their sources?

1) Iron =makes haemoglobin in red blood cells allowing for the transport of oxygen around the body

• Red meat

• Spinach

2) Calcium = strengthens teeth and bones

• Dairy (milk, yoghurt, cream)

Determine the main function of fibre in the body and its sources

→ An insoluble substance that acts as bulk to push feces through the intestine to prevent constipation and colon cancer

• Wheat

• Pasta

• Fruits and Vegetables

What is the main function of water?

→ Assists with metabolic reactions in the body and also acts as a solvent for substances to dissolve in

Define a ‘balanced diet’

Having the correct proportion of different food groups to give the body the energy it needs to carry out tasks.

What factors can affect the energy needs of a person?

• Pregnancy

• Weight

• Career, Activity levels (how much they exercise)

• Age

• Height

• Gender

Define ‘malnutrition’

a lack of excess or imbalance in the nutrients a person takes in their body

What is a deficiency disease?

An illness cause by the lack of essentials of nutrients, vitamins, minerals and protein in a person’s diet

What is a deficiency disease caused by lack of Vitamin C?

→ Scurvy

(bleeding gums, fatigue, joint pain)

What is a deficiency disease caused by lack of Vitamin D?

→ (Rickets)

Stunted growth

Muscle Weakness

Muscle pain

What is a deficiency disease caused by lack of Iron?

→ Anaemia

Pale Skin

Fatigue

Dizzyness

Shortness of breatj

How can we test for simple sugars (glucose) in a food?

→ Benedict’s Test

1) Take food sample and place in test tube

2) Place test tube in thermostatically controlled water bath at 80 decrees C

3) leave for 5 minutes and observe colour change

results:

• Brick red = high conc

• Orange = medium conc

• Green = Low conc

• Blue = no conc

Why is the benedict's test semi quantitative?

The gradual change in color and precipitate formation allows you to estimate the approximate concentration range rather than just a simple yes-or-no answer.

How can Starch, Fibre and Sugar be split into smaller reducing sugars?

1) Starck → Maltose → Glucose

2) Fibre → Lactose → Fructose

3) Sugar

How can we test for Starch as a complex carbohydrates?

→ Iodine test

1) Place sample on white tile plate

2) Add a few drops of iodine solution

3) Observe colour change

Results:

Orange/brown = negative

Blue/black = positive

How can we test for proteins?

→ Biuret test

1) Place food sample in test tube

2) Add a few drops of Biuret solution

3) Observe colour change

Results:

• Stays Blue = Negative

• Lilac/purple = positive

How can we test for Fats?

→ Emulsion test

1) Add food sample to test tube

2) Add some ethanol and mix

3) Add water into seperate boiling tube

4) Pour some of ethanol mixture into boiling tube

5) Observe colour change

Results:

• Stays colourless= negative

• Becomes cloudy white = positive

Why is the test for fats known as the emulsion test?

The cloudy white solution formed that show the test is positive relies on the suspension of fat droplets