- Saponification:
Alkaline hydrolysis of an ester where the ester is boiled with sodium
hydroxide, NaOH or potassium hydroxide, KOH solution to produce an alcohol and
a sodium or potassium salt of a carboxylic acid.
- Soap is not an effective cleansing
agent in hard water but is only effective in soft water. Detergent is an
effective cleansing agent in both hard water and soft water.
- Soft
water: Water that does not contain mineral salts such as
magnesium salt or calcium salts.
- Hard
water: Water that contain mineral salts.
- Food
additives are substances added to food to preserve flavor or
enhance its taste and appearance. Types of additives are preservatives, antioxidants, flavourings, stabilizers,
thickening agents and food dyes (colourings).
- Medicines: a
compound or preparation used for the treatment or prevention of disease,
especially a drug or drugs taken by mouth. Types
of modern medicines are analgesics, antibiotics, stimulants, antidepressant
and antipsychotic.
- Thickening
agents: substances added into food to reduce its amount of water
so that the food is thickened. Examples: pectin, acacia gum, gelatin.
- Food
dyes (colourings): substances added to food to add or restore
the color of food in order to enhance its visual appeal and to match consumer
expectations. Examples: Azo compounds such as tartrazine, triphenyl compounds
such as brilliant blue FCF. Azo compounds are usually red, orange, brown or
yellow in colour while triphenyl compounds are usually blue or green in color.
- Stabilisers:
substances added into food to prevent an emulsion from being separated out.
Examples: Lecithin, mono- and di-glycerides of fatty acids.
- Flavourings: substances
added to food to improve the taste of food and to restore taste loss due to
processing. Examples: Sugar, vinegar, common salt, aspartame, monosodium
glutamate, synthetic essences such as penthyl ethanoate.
- Antioxidants: substances
added to food to prevent oxidation by air that can cause rancid fats and browning
of fruits. Examples: ascorbic acid, sodium citrate, tocopherol, butylated
hydroxyanisole (BHA), butylated hydroxytoluene (BHT).
- Preservatives:
Subtances added to food to slow down or to prevent the growth of microorganisms
so that food can be kept for a longer period of time. Examples: sodium
benzoate, sulphur dioxide, sodium nitrite, potassium sorbat.
