FOOD PRODUCTION NOTES

TOPIC SEVEN

FUEL

DEFININATION:

FUEL: Is any material used for producing or providing energy.

Sources of energy in the kitchen.

·        Solid fuel wood and charcoal.

·        Gas

·        Electricity

·        Solar

·        Biogas

·        Paraffin.

Solid fuel.

1.Wood:

 Is used for cooking, warming. The house and heating.

 

Points to note when using wood.

A.use when dry to avoid too much smoke and soot.

B.cut it into reasonable sizes for convenience and to avoid accident.

Advantages of wood

-relatively cheap.

-it is easy to use.

Disadvantages of wood.

-difficult to collect especially during the rainy season.

-takes a lot of space especially during storage.

-dirty to use because it produces soot and smoke which blackens cooking utensils and ceiling.

-smoke irritates the eyes and the respiratory system.

 

2. Charcoal.

          It is the black porous residue of burnt wood

Charcoal is obtained by burning in the absence of oxygen

Charcoal does not produce as much smoke as wood

Charcoal is very produce for grilling meat

Disadvantages

·        A lot of labour required for lighting, refueling and cleaning charcoal grill

·        Lack of flexibility in use of charcoal hard to control

·        Restriction in cutting wood (trees) for burning charcoal.

·        Charcoal is not clean in use or storage

·        It is not readily available in some areas

·        The kitchen has to be well ventilated, because carbon-dioxide produced by burning charcoal can cause death.

Points to note when using charcoal.

-the kitchen has to be well ventilated.

-charcoal should be stored in a dry place.

 

3. GAS

-Gas is a by-product of petroleum.

-it burns in air to give off carbon-dioxide and water.

-Gas is stored and sold in cylinders of various sizes.

 

Advantages of gas.

-gas is clean (not dirty) free from smoke.

-easily controlled convenient and labour saving.

-it is portable.

-special utensils are not required.

 

Disadvantages of gas.

-some heat is lost in the kitchen.

-regular cleaning required for efficient working.

-gas burns produce carbons-dioxide and water therefore adequate ventilation must be provided as carbon-dioxide would affect the staff.

-leaking gas is poisonous and can explode when ignited

-it is expensive.  In Kenya is not available to everybody

-Special utensils are required                                                                                                                                             

-Initial cost of equipment and maintenance is high

Points to consider when using gas

          -equipment must be serviced regularly to avoid leakage

          -the gas should be used in well ventilated rooms

          -the gas should be turned off when not in use to avoid wastage

          -cylinder should be stored in a lockable place for safety

          -the smell indicating that gas is leaking therefore it shouldn’t be lit immediately.

          Check and rectify the fault and all the leaked gas to escape before lighting the        

          Cooker.

Points to note when using electricity

·        electricity wires should be properly insulated to avoid accidents

·        sockets should not be overloaded

·        equipment should be repaired regularly

·        never poke the sockets with any objects

·        put off when not in use

·        avoid handling switches with wet hand to avoid electric shock

4. Solar

Energy is directly trapped from the sun

Solar cooker works only on solar energy

Advantages

1. Solar cooker gives no smoke and no soot clean to use

2. Keeps our environment clean

3. It conserves the precious energy resources of the country eg cutting down trees for wood and charcoal

4. preserves the nutrition value of the food because the cooking is done at a low temperature

5. Does not require constant attention

6. Keep food hot for a long time

Disadvantages

Energy cannot be trapped when it is cloudy when it rains

 Paraffin

Paraffin is a byproduct of crude oil

Advantages

·        it is fairly cheap

·        readily available

·        it is quick to light and easy to use

·        it is easily stored

Disadvantages

It can cause fire if carelessly used and stored

It gradually soot which makes cleaning efficient

It has unpleasant smell

Needs large storage tanks

Points to note when using paraffin

The lid of the storage containers should fit tightly

Store away safely from food stuff

Keep away from open fires

HEAT TRANSFER

Transference of heat is carried out by one of the three methods

1. Conduction

2. Radiation                                                                         

3. Convection

 

 CONDUCTION

The transfer of heat is by contact. It is the travelling of heat through a solid. Food is in contact with a hot vessel and water or heat is from one solid to another provided they are in contact.eg sauce pan full of water in a hotplate

RADIATION

This is the way heat is transferred through space from its source to a cold object

This type of heat travels in straight rays and only warms the solid, it gets (i.e. the rays gets) into contact with

The straight line heat rays gets absorbed by the solid object and becomes heat energy e.g. is the salamander heat and the sun

CONVECTION

It is the passage of heat through liquids and gases.

E.g. water in a saucepan being heated the water at the bottom becomes lighter .hence rises to the top through convection currents and the heavier cold water takes its place at the bottom.eg in the oven, heated air is convected around the oven that is the lighter air tends to move upwards and the cold air moves downwards.

ENERGY CONSERVATION.

-it is saving energy by using it economically.

-moderate improvement in efficiency and rationalization in use of equipment could save a lot of energy.

- Control of fuel use requires careful planning.

Energy conservation methods /points to observe when using energy.

1. Jiko: use fuel saving jiko’s or stoves which use (consume) less fuel to perform various cooking and heating tasks

2. Gas: when using a gas cooker do not allow the flame to escape the outside of a pan and always turn off the gas removing the pan from the burners.

3. When lighting a gas burner strike the match first and then turn on the gas.

4. Electricity: when using electricity cookers ensure that only the switch control for unit being used is on.

5. Switch off the heat a few minutes before cooking is complete so as to use the heat present.

6. The sauce pans, sufuria’s or frying pans used should be flat at the bottom so that the whole sufuria covers into contact with the heating surface.

7. Put the utensils on the heating unit before switching on the heat.

8. Use the light size of sufuria for the right heating sufuria covers the heating unit well to avoid wastage of the heat from side.

9. When boiling food reduce the heat to simmering position.

10. Pots and pans should be covered as far as possible to reduce the amount of heat loss and shorten the cooking time.

11. Avoid reducing opening of oven as you are baking as this reduces temperature.

12. Cheap methods of supplying energy should be employed e.g. pressure cooking cooks in a few minutes.

 

Safety precautions when using fuel.

Certain cooking devices are safer to use than others and vice-verse.

1. The economy Jiko which have insulated walls offer better protection from burns.

2. Burning charcoal is dangerous if used in a confined place or space without good ventilation as poisonous carbon-dioxide produced cause death.

3. When using an oil stove, never use water to extinguish an oil fire.

4. Keep the supply of gas (e.g. cylinder) out of reach either by locking up cylinders when not in use carelessness may lead to an explosion.

5. Watch out for leaking gas as it can be poisonous and also dangerous in case the gas is ignited.

6. Wet hands or utensils may cause electric shock in case there is a short circuit in the power system.

Hands should be used thoroughly dry before to switch on electricity and electric unit avoid using hands to test the temperature cooker before.

7. Never open a pressure cooker before release and cool all the pressure is released.