Absorption
The soaking-up of frying oil caused by food fried in it. Absorption is affected by the frying temperature and porosity of fried food.
Antifoaming agent
Ingredient added to frying oils to reduce the formation of foaming.
Antioxidants
Compounds that can inhibit the development of oxidation.
Breakdown
Any detrimental chemical or physical change, which occurs in the frying oils, such as foaming, off-flavour, dark colour, smoking, or gumming.
Cholesterol
A sterol found in animal tissue; synthetized in the body (endogenous cholesterol) and consumed in the diet (exogenous cholesterol). The importance is to evaluate the blood levels of good HDL cholesterol versus the blood levels of bad LDL cholesterol.
Essential fatty acid
Polyunsaturated fatty acids that cannot be synthetized by the body, including linoleic and alpha-linolenic, and that are needed for human growth and development.
Fat
Chemical compounds (lipids) found in both plants and animals. Fats are necessary for life. They are predominately made from a glycerol molecule and three fatty acids. This compound is commonly called a “triglyceride”.
Fatty acids
Chains of carbon and hydrogen atoms with a carboxyl and methyl group at either or opposite ends; the degree of saturation and thus the physical properties of a fat depend on the number of double bonds present between the carbon atoms.
Fire point
The temperature at which heated oil burns with a flame when ignited.
Flavour
A sensation aroused by taste. Flavour variations may be described as bland, neutral, nutty, tallowy, fruity, reverted, and rancid, etc.
Foaming
A persistent layer of fine bubbles, which forms on the surface of the frying oil during use. It is an indication of solid fat breakdown
Free fatty acid
Fatty acids characterize the identity of the oil. When oil is abused by heat, oxygen, moister or light, or is aged to a great extent, two things can happen to the fatty acids. They can break off from the glycerol molecule and exist in the oil as “free fatty acids”. They can be attacked at the site of the double bond, which is far more fragile than a single bond, resulting in one or more new compounds, which impart objectionable flavours and odours to the oil, and turning the substance into rancid oil.
Fry life
The length of time during which frying oil is able to produce fried foods of acceptable quality.
Gums
A sticky material, which forms when oil or fat is heated over long periods of time. It is produced by oxidation and polymerization of the fat. Gumming material on the heating surfaces is a sign the oil or fat is breaking down.
High oleic sunflower oil
Oil produced from high oleic acid oil-bearing seeds of varieties derived from sunflower seeds (seeds of Helianthus annuus L.).
HDL
High density lipoproteins. Molecular complexes found in the blood that carry cholesterol. Cholesterol bound to HDL is transported in the body to the liver for elimination, and is considered a good type of cholesterol.
LDL
Low density lipoproteins. Molecular complexes found in the blood that attach to cholesterol. Cholesterol bound to LDL is considered as bad cholesterol because it deposits on the walls of arteries.
Melting point
There are many different tests to determine the speed and/or degree of melting. However, for simple frying applications, the melting point is merely the temperature at which a solid fat becomes liquid.
Monounsaturated fatty acid
Fatty acid containing one double bond between carbon atoms; replacing saturated fats by monounsaturated fatty acids, like oleic acid or polyunsaturated fatty acids contributes to the maintenance of blood cholesterol levels.
Odour
The sensation produced when various components act on the olfactory nerves in the nose.
Off-flavour and/or odour
Any flavour or odour that is not typical of either a particular frying oil or a food being fried.
Oxidation
The most common cause of fat breakdown. It is a chemical reaction between oxygen and fat. Oxidation in fats or food products containing fat eventually results in the development of rancidity and objectionable flavours and odours.
Palm oil
Oil derived from the fleshy mesocarp of the fruit of the oil palm (Elaeis guineensis)
Peroxide value
A number that indicates the level of peroxides in a fat or oil that has developed as a result of oxidation. Peroxides are considered intermediates in the lipid oxidation reaction scheme. The peroxide value is a good parameter to evaluate the quality of the oil. A high peroxide value means a low quality oil.
Peroxides
Oxidized fat molecules that eventually degrade to off-flavours.
Rancidity
Characterized by development of easily recognized sharp, acrid and pungent off-flavours and odours. True rancidity is a description of sensory reactions and may be determined only by flavour and odour.
Rapeseed oil
Oil produced from seeds of Brassica napus L., Brassica rapa L., Brassica juncea L. and Brassica tournefortii Gouan species.
Saturated fatty acid
Fatty acid not containing any double bonds between atoms; saturated fatty acids raise the blood cholesterol level, and hence their dietary intake should be limited.
Smoke point
The temperature at which the frying fat will give off a continuous column of smoke above the fryer, while being heated.
Stability
The ability of a frying fat/oil to resist chemical and/or physical changes. This is the relative resistance of a fat, oil or a food product to any undesirable type of breakdown of change in character. For fats and oils, stability may refer to resistance to oxidation, hydrolysis, rancidity, and the formation of off-odours and flavours.
Stearic acid
A saturated fatty acid; it seems to have a neutral effect on blood cholesterol levels.
Sunflower oil
Oil derived from sunflower seeds (seeds of Helianthus annuus L.).
Trans fatty acid
Fatty acid occurring naturally in meat and dairy products, and occur in partially hydrogenated vegetable oils/fats; hydrogen atoms are located on opposite site of the double bond. Trans fatty acids are geometric forms of fatty acids. Both trans fatty acids have similar negative health effects and their intake should be limited.
Tocopherol
A class of fat soluble compounds that have vitamin E activity, and function as antioxidants. Tocopherol is a natural compound in vegetable oils.
Vegetable fat
Fats and oils delivered from plant source.
Viscosity
The thickness of a liquid or semiliquidmaterial.