2010年9月30日星期四

Food processing and packaging.
Pasteurisation
- process use to preserve milk by killing the bacteria, by French scientist, Louis Pasteur.
- heated up to 72C for 13 sec or 63C for 30 min, immediate coolong & packaging.
- does not kill the spores of bacteria
- preserves natural flavour as well as its nutritional value.

Dehydration
- removal of water or moisture from food
- dehydrated by blowing hot air frm drying machines.
- some nutrient may be destroyed.

Freeze-drying
- decrease temp to -18C & vacuuming out the icicles formed.
- maintain its colour, taste and texture

Canning

- cheap, shelf life for at least 2 years
- cans heated to high temp of 120C, kill microorganisms & spores.
- additives added, air is drawn out frm the cans n quickly sealed.


Ways to improve food Production
1. kill microorganism
- bacteria n fungi r decomposers n grow well in warm n moist conditions.

2. to make food last longer
- micro r killed when food is being processed. preserved n last longer.

3. help in packaging the food 4 easy transportation


4. to ensure a constant supply 4 food.

5. provide consumers wif wider choice of food production.

6. help in digestion.


Processed food
- low in fibre, antioxidant, vitamins & mineral content.
- contain food additives.
- transported over long distances n kept over a period of time.
foods tht r altered, manufactured in factories n packed in plactic bags, boxes, cans, jars n bottles.
- eg. frozen food, canned food, biscuit, bread, milk, cheese n choc.

Unprocessed food.
- natural form
- high fibre, antioxidant, vitamin n mineral content.
- do not contain food additives
- spoilt easily
-eg. fresh fruit, vege, herbs, meat.



Improve food production
Due to :
- increases of world population, increases demand 4 food.
- increase quantity to vercome starvation.


Use of quality breeds
produce larger quantity of quality yields in short period of time.
a. tenera - the variety of oil palm tht
= cross betw the Pisifera n Dura varieties
= has thick mesocarp, thin shell n large kernel
= able to produce more palm oil

b. Exotica - variety of papaya tht
= cross btw Hawaiian Solo n Subang 6 varieties

c. Masmadu - variety of maize tht
= cross btw Taiwan n Mexican varieties
= sweet fruits
= crop is more resistant to diseases, has shorter fruiting period n produces high yield.

d. Mafriwal - quality breed of cattle tht
= cross btw Feiesien n Sahiwal
= can produce more milkn meat.
= suited to local condition

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