Chapter 19 - Food Preservation Flashcards
Explain one advantage of using additives in processed food.
Additives can help to improve the colour, flavour, texture or taste of the product. Some additives can also help to increase the shelf life of the product.
Explain one disadvantage of using additives in processed food.
Certain food additives may cause certain cancers. Artificial food colouring has also been linked to increased hyperactivity in children.
Example for the following food additives.
- sweetening agent:
saccharin
Example for the following food additives.
- flavouring agent
monosodium glutamate (MSG)
Example for the following food additives.
- stabilizing agent
guar gum
Example for the following food additives.
- colouring agent
tartrazine
Give the disadvantage of excessive consumption of the following food additives.
- sodium nitrate
colorectal cancer
Give the disadvantage of excessive consumption of the following food additives.
- sodium bisulphite
headache/ difficulty in breathing
What are the different methods of food preservation.
- Drying - Food is dried under the sun (Eg. Fish)
- Dehydration - removal of water using artificial means such as freeze – drying ( Eg. Powdered milk)
- Freezing
- Heat sterilisation - Food is heated in sealed containers at such high temperature that all microorganisms present are killed. (Eg. UHT milk)
- Pasteurisation - heating of food but at a lower temperature (Pasteurised milk)
- Using preservatives - substances that are added to the food (Eg. Jam)
- Vacuum packing food is placed in bags and the air in the bags removed. (packed sausages)
- Using ionising radiation-food irradiation - irradiation is a method of preservation where food is exposed to ionising radiation (gamma rays) to kill microorganisms and insects. (Eg. prevent potatoes from sprouting)
Explain how food should be stored safely in a refrigerator.
● Use food in rotation - prevents waste
● Wipe milk bottles - to prevent dirt from outside being brought in
● Keep raw and cooked food separate - prevent cross-contamination
● Do not mix raw and fresh food- prevent cross-contamination
● Keep raw meat at bottom - prevent juices dripping onto cooked food
● Temperature must be approx. 4 degrees - to slow down growth of micro-organisms
● Do not put hot food into refrigerator - increases temperature inside, cause bacteria to multiply
● Throw away old food - could be dangerous to eat
Explain how food should be stored safely in a refrigerator.
[Continue]
● Cover strongly smelling food - to prevent tainting other food
● Cover food- to avoid bacteria reaching food/prevent surface of the food from drying
● Use clean containers - free from bacteria from other food
● Clean regularly - to ensure free from bacteria/remove spills
● Keep door closed- to prevent escape of cold air
● Cover or wrap food - to prevent drying out
● Do not overcrowd - to allow cold air to circulate etc
● Note use by date- so food is used when safe
What is natural food additives.
These additives are produced from natural sources (animals and plants).
Eg. Papain, an enzyme obtained from papaya leaf or fruit is used for tenderising meat.
Salt, sugar and honey have been used to preserve food since ancient times.
Herbs and spices, which are the aromatic parts of plants are also used for adding colours and flavours to food.
State the reasons for preserving food.
● Enjoy food out of season
● Food lasts longer/ prevents decay
● To cope with a glut
● Prevents spoilage
● To prevent waste
● Easier to transport/store
● To give variety [Eg. food can be frozen, dried]
● Can enjoy foods from other countries
● Not destroyed by micro-organisms
● New products made [Eg. jam, pickles etc]
● To have a store of food. [Eg. Useful in emergencies]
