1. Fats and oils

2. Functions of fats Provides texture and flavour to food
Gives a feeling of fullness (satiety) after a meal.
Slows down digestion.
Concentrate source of energy (more tan proteins and carbohydrates)
energy
reserve of energy
protects vital organs
insulates/preserves body heat
source of fat soluble vitamins/A D E K
increases calorific value of foods without adding bulk
provides texture to food
provides flavour
gives a feeling of fullness (satiety) after a meal
slows down digestion
formation of cell membranes

3. Functions Reserve of energy (fuel)
Protects vital organs/ shock absorber
Insulates/preserves body heat
Source of fat soluble vitamins / ADEK
Increases calorific value of the food without adding bulk
Formation of cell membranes

4. Chemistry of fats and oils
At room temperature fats are solids and oils are liquids.
The elements that are present in fats are C, O and H.
They form the glycerol and the fatty acids molecules that combine to give a greater compound called fat.

5. Chemistry of fats and oils
Fat is a general term used to say fat or oil.
The scientific term lipid is for any type of fat not necesarily edible.

6. Types of fats and oils Examples: Butter Saturated fat: Lard
Dripping
Suet
Ghee
Margarine
Saturated fat:
Contains maximum amount of hydrogen.
Molecule has only single bonds.
Solid/hard at room temperature
Usually from animal

7. Examples: Avocado Pear Olive oil
Monounsaturated fat:
Molecule can accept more hydrogen.
Molecule has one double bond.
Liquid at room temperature
Usually from plants.
Examples: Avocado Pear Olive oil

8. Polyunsaturated fats:
Molecule can accept more hydrogen.
Molecule has more than one double bond.
Liquid at room temperature
Usually from plants.
Examples:
Sesame seed oil
Sunflower oil
Maize oil
Palm oil
Peanut oil
Oily fish (salmon, herring, tuna, pilchard, mackerel)
Fish-liver oil

10. Reasons to reduce the amount of fat in the diet.
Excess fat is stored:
Under the skin
Round internal organs
Leading to:
Obesity
Breathlessness
Lethargy
Hypertension
Strokes
Lack of self-esteem
Linked to Coronary Heart Disease (CHD)
Cholesterol deposited in the arteries, narrowing, blocking.
Cause heart attack and problems during surgery.

11. Ways to reduce fat in meals
Remove visible fat from meat
Grill instead of fry
Absorb excess fat before serving fryed food
Cut chips thicker (less surface area in contact with fat)
Spread butter thinly
Reduce the consumption of cakes and bicuits
Eat less chocolate/ potato crisp/nut, etc
Use skimmed or semi-skimmed milk
Choose reduce fat yogurt, cream, cheese, mayonnaise, etc.

12. Digestion and absorption of fat
In duodenum:
Bile – from gall bladder
In liver – emulsifies fat- breaks fat into small droplets-increases surface area

13. In ileum: Lipase – from pancreatic juice changes fat to fatty acids and glicerol.

14. Digestion and absorption of fat
In small intestine:
Finger-like projections -Villi – contain lacteal absorbs fatty acids and glycerol and recombine to form fats
Pass into lymphatic fluid and join blood circulation as insoluble fat.

15. Essential fatty acids
Must be included in the diet because cannot be manufactured by the body
Deficiency causes dry skin / poor hair / diarrhea
 The only two essential fatty acids for the human being are:
α-linolenic acid (ω-3)
and
Linoleic acid (ω-6)

17. Fuentes