- Food preservatives are classified into two main groups: antioxidants and antimicrobials
- Antioxidants are compounds that delay or prevent the deterioration of foods by oxidative mechanisms.
- Examples of antioxidants are ascorbic acid (vitamin C) and citric acid.
- Antimicrobial agents inhibit the growth of microorganisms in food.
- Examples of antimicrobials are acetic acid (vinegar), sulphur dioxide, sodium sulphite, benzoic acid, sodium benzoate, sodium nitrite and sodium nitrate.
- Table below shows the uses of a few types of preservative that common used in our daily life.
|Sulphur dioxide, Sodium sulphite
|Prevent browning of fruit juice
Keep the colour of vegetables
|Benzoic acid, Sodium benzoate
|Preserve sauces. Example, tomato and chilli sauce.
|Sodium nitrite, Sodium nitrate
|Preserve meat, canned food and cheese.
Make the food look fresh.
Advantage and Disadvantage of Food Additives
- Can prevent the growth of microorganisms and hence keep food for a longer time.
- Improve nutritional in food
- For medical purposes. For example, artificial sweetener diabetes patient.
- taking with excess quantities can cause health problem.
- has low nutritional value.