Download Amino acid An organic compound containing both an

Amino acid
An organic compound containing both an amino group
(-NH2 ) and a carboxyl group (-COOH); essential component of proteins.
Anion
A negatively-charged ion.
Antioxidant
A substance which slows oxidation.
Anti-caking agent
A substance which enables a powder to flow freely.
Artificial sweetener
Substances which are not carbohydrates but which have the ability to impart
the sensation of sweetness.
Bactericidal
A substance (e.g. preservative) having the ability to kill bacteria.
Bacteriostatic
A substance (e.g. preservative) having the ability to slow down the growth of
bacteria.
Calories, kilocalories/
kilojoules
Units of energy; 1 Calorie = 1 kcal = 4.2 kJ.
Carbohydrate
Compounds which contain the elements carbon, hydrogen and oxygen; there is
always twice as much hydrogen as there is oxygen. Made up of sub units
called simple sugars; carbohydrates are one of the major classes of nutrients;
one function in the body is as an energy source.
Chelators
Substances capable of combining with free metal ions; they are important in
preventing the oxidation of food. EDTA is an example of this.
Emulsifier
A substance which allows an emulsion to stay in a stable state.
Emulsion
Tiny drops of one liquid spread evenly through a second liquid.
Enzymes
Biological catalysts, protein in nature, which control the rate of all biological
reactions; some have uses in the production of food.
Fatty acid
Molecule made up of unbranched hydrocarbon chains having about 14-24
carbon atoms with an acidic group (see saturated/unsaturated fatty acids).
Fats
Compounds which contain the elements carbon, hydrogen and oxygen; made
up of sub units called glycerol and fatty acids; fats are one of the major classes
of nutrients; one function in the body is to provide energy.
Fermentation
A process carried out on a carbohydrate source by some microorganisms,
particularly yeasts, which produces alcohol and carbon dioxide. Used in
brewing and baking.
Firming agents
Food additives used to prevent the loss of crispness to fruit and vegetables
during processing.
Foam
The dispersal of a gas in a liquid.
Food additive
Food additives are those substances deliberately added to food by the
manufacturer to facilitate processing or to improve the appearance, texture,
flavor, keeping quality or nutritional value of foods.
Fungicidal
Compound (e.g. preservative) having the ability to kill fungi and moulds.
Gel/gelation
Gels are systems where large volumes of liquids can be held stationary by
small amounts of solids; gelation can be caused by polysaccharides such as
starch or proteins such as gelatin.
Glucose
A simple sugar; a monosaccharide; the most common substrate for respiration.
Gluten
A protein found in flour; it has stretching and elastic properties which allow it to
provide a network within dough which can trap carbon dioxide.
Glycerol
A sweet, sticky liquid containing three alcohol groups; it can combine with one,
two or three fatty acid molecules to give a mono-, di- or tri-glycerides.
Humectant
A substance capable of keeping other substances moist; added to food to
prevent it from drying out.
Hydrophilic
Hydro = water, philic = loving; substances that are hydrophilic will dissolve in
water.
Hydrophobic
Hydro = wate r, phobic = hating; substances which are hydrophobic will not
dissolve in water.
Hygroscopic
Capable of absorbing water from the air.
Ions
Molecules or atoms which carry a positive (cations) or negative (anions)
electrical charge.
Immiscible/miscible
Liquids which will not mix to form a homogeneous substance when combined
are said to be immiscible, e.g. oil and water; liquids that completely mix on
combining are miscible, e.g. water and alcohol.
Microorganism
Microscopically small organisms such as viruses, bacteria, protozoa and fungi.
Bacteria and fungi are principally responsible for decay in food.
Oxidation
A chemical reaction which involves at least one of the following: loss of
electrons, the gain of oxygen or the loss of hydrogen. (Rust is the result of the
oxidation of iron; the oxidation of fats in foods results in rancidity.)
Pectin (E440)
A plant polysaccharide capable of producing a gel and hence has important
setting properties, particularly, in the production of jams.
pH
A measure of acidity or alkalinity.
Polysaccharide
Poly = many, saccharide = sugar; polysaccharides are the carbohydrates made
up of many sugar sub units.
Polyunsaturated fatty
acids
The occurrence of two or more carbon to carbon double bonds in a fatty acid
chain will result in a polyunsaturated fatty acid (see saturated fatty acids).
Preservatives
Substances capable of slowing down or preventing the reactions of decay.
Proteins
Compounds which contain the elements carbon, hydrogen, oxygen, nitrogen
and sometimes, but not always, phosphorus and sulphur. Consist of sub units
called amino acids; one of the major classes of nutrients having a wide range
of biological functions.
Rancidity
Process in which fats exposed to the air undergo oxidation and liquefy. Other
reactions, such as hydrolysis, take place which result in the release of foul
smelling free acids.
Stabilizers
Food additives which help to retain the physical and textural properties of food
particularly emulsions and low fat systems.
Starch
Storage polysaccharide in plants; has important thickening properties.
Tenderizers
Substance or processes which alter the fibrous structure of meat to make it
less tough.
Volatile
A liquid which easily evaporates into a gas.
Viscosity
A measure of the 'runniness' or 'flow' of a liquid. Water is less viscous or more
runny than treacle.