10 - Food Additives Flashcards
What are food additives?
Substances added to food to cause a desirable change in the product’s characteristic.
May or may not have nutritional value
Food additives:
What are intentional additives?
Substances added to improve the properties of foods which are added on purpose
e.g., antioxidants in oil to prevent oxidation sweetener antimicrobials colours flavours emulsifiers
What are adulterants?
Added intentionally but do not improve the properties of foods and should not be in the food
NOT food additives
e.g., melamine in milk powder
can be harmful, reduce the quality of food or harmless
What are contaminants?
Substances which get into food unintentionally
e.g., tin leeching into pineapple syrup antibiotics hormones dioxins hair insects packaging materials
What are the functions of food additives?
Preservation Sensory Emulsifiers Thickeners, stabilisers and gelling agent Anticaking agents
How do food additives preserve food?
Antimicrobial (e.g., salt, sugar, nitrites, acids)
Antioxidants
Sulfites - antioxidants, antimicrobial but aggravates asthma and allergic reactions and reacts with thiamine
How are antioxidants used as food additives?
Chelate metal ions which cause rancidity
Added to cooking oil, coating and packaging of materials, or used as dipping solution
How do food additives affect the sensory aspect of food?
Colouring
Acid/base regulator (e.g., prevent colour change)
Flavours
Flavour enhancers (e.g., MSG - umami taste, soy salt can be used to replace salt)
Sweeteners (nutritive or non-nutritive)
What is the difference between orange juice and an orange flavoured drink?
Natural vs synthetic flavours
Synthetic flavours lack complexity but consumers may not be able to tell the difference vs natural flavours
Drinks with the same flavours but different colours can be perceived differently
How do food additives act as emulsifiers?
They help water and oil to mix e.g., lecithin
(Used in salad dressing, ice cream, mayonnaise, margarine, etc.)
Emulsifiers can improve texture of foods
Why are food additives used as thickeners, stabilisers, gelling agents, and texturising agents?
Improve texture and consistencies of many foods
e.g., agar, locust bean gum
How do food additives act as anticaking agents?
Absorb moisture e.g., calcium silicate, silicon dioxide, calcium phosphate
Prevent powdered and crystalline materials from caking or forming lumps
e.g., table salt, baking powder
Safety of food additives:
What is ADI and how is it calculated?
Allowable/acceptable daily intake = level with no observable harmful effect / 100
How are food additives regulated in Singapore?
Singapore’s Food Act is set by Singapore Food Agency (SFA)
Food additives must
- be proven safe at the level used in foods
- have an advantage when used
Some food additives are labelled by their code (E-numbers)
How are food additives classified?
GRAS - generally recognised as safe
Controlled substances - guidelines for quantity used in ppm (by weight) for each type of food is needed
