Food Additive

  1. Food additives are substances added to food to preserve it or improve its flavour and appearance.
  2. Some of the commonly used food additives include preservative, colourants, stabilizers and flavouring.
  3. The chart below summarise the 4 groups of food additive

Effects of Food Addictive on Health

Food additive have the following effect on health.
  1. Allergy
    – MSG causes chinese restaurant syndrome
    – Sodium nitrate/ sodium nitrite causes blue baby syndrome
  2. Cancer
  3. Brain Damage
    Food additive can disrupt the supply of oxygen to brain and hence cause damage to the brain.
  4. Hyperactivity
    colouant such as tartazine can cause hyperactivity


  1. Food preservatives are classified into two main groups: antioxidants and antimicrobials
  2. Antioxidants are compounds that delay or prevent the deterioration of foods by oxidative mechanisms.
  3. Examples of antioxidants are ascorbic acid (vitamin C) and citric acid.
  4. Antimicrobial agents inhibit the growth of microorganisms in food.
  5. Examples of antimicrobials are acetic acid (vinegar), sulphur dioxide, sodium sulphite, benzoic acid, sodium benzoate, sodium nitrite and sodium nitrate.
  6. Table below shows the uses of a few types of preservative that common used in our daily life.
Sulphur dioxide, Sodium sulphitePrevent browning of fruit juice
Keep the colour of vegetables
Benzoic acid, Sodium benzoatePreserve sauces. Example, tomato and chilli sauce.
Sodium nitrite, Sodium nitratePreserve meat, canned food and cheese.
Make the food look fresh.
Advantage and Disadvantage of Food Additives


  1. Can prevent the growth of microorganisms and hence keep food for a longer time.
  2. Improve nutritional in food
  3. For medical purposes. For example, artificial sweetener diabetes patient.


  1. taking with excess quantities can cause health problem.
  2. has low nutritional value.


Natural colorants

  1. Most natural colorants are extracts derived from plant tissues. 
  2. The disadvantage of using natural colourants are
    1. colour intensities not consistent, 
    2. not stable (colour may change when exposed to light and heat,)
    3. may react with food.
    4. may have unwanted flavours and odours. 
    5. Supply can be instable

Synthetic Colorants (Dye)

  1. Most of the synthetic colourants are complex chemical compounds sthat synthesized from petroleum.
  2. Examples of syhthetic colourants are azo compound and triphenyl.
  3. Azo compound colourants normally are yellow, red, brown and white in colour.
  4. Triphenyl compound colourants are green, blue or purple in colour.

Side effects

Many of the artificial food colorings cause reactions in sensitive individuals ranging from hyperactivity to depression to asthma-like symptoms.


  1. A stabilizer is a substance to prevent or to slow down some unwanted physical changes of food.
  2. Most stabilizing and thickening agents are polysaccharides, such as starches or gums, or proteins, such as gelatin. 
  3. The primary function of these compounds is to act as thickening or gelling agents that increase the viscosity of the final product. 
  4. These agents stabilize emulsions, either by adsorbing to the outer surface of oil droplets or by increasing the viscosity of the water phase. 
  5. Thus, they prevent the coalescence of the oil droplets, promoting the separation of the oil phase from the aqueous phase.

Flavouring Agent and Sweeteners

  1. Natural flavourings are derived or extracted from plants, spices, herbs, animals, or microbial fermentations. 
  2. Artificial flavourings are mixtures of synthetic compounds that may be chemically identical to natural flavourings. 
  3. Artificial flavourings are often used in food products because of the high cost, lack of availability, or insufficient potency of natural flavourings.
  4. Example of commonly used flavouring is esther, which will give fruity smell to food.

Flavour Enhancers

  1. Flavour enhancers are compounds that are added to a food to supplement or enhance its own natural flavour. 
  2. Examples of flavour enhancers are monosodium glutamate (MSG).
  3. Monosodium glutamate is found in tomatoes, potatoes, mushrooms, and other vegetables and fruits


  1. A sweetener is a food additive which adds the basic taste of sweetness to a food.
  2. Sucrose or table sugar is the standard on which the relative sweetness of all other sweeteners is based. 
  3. In addition to saccharin, the most commonly used nonnutritive sweeteners are cyclamates, aspartame, and acesulfame K.