Lipid, Oil, and Fat Testing

Oils, fats and lipids are relatively interchangeable names for a variety of chemical compounds that share common solubilities in organic solvents such as ether, chloroform, and/or methanol.

Eurofins' laboratories can expertly conduct a number of analyses relevant to determining the quality and/or physical properties of fats and oils.

IODINE VALUE

Iodine Value (IV) is the grams of iodine absorbed by 100 grams of fat.

This value is used to measure the relative degree of unsaturation in fats. Unsaturated fats have higher IV's than saturated fats. The traditional method for this determination is known as the WIJS method.

Iodine Value may also be calculated from a fatty acid composition as its value is closely related to the number of double bonds present in the fat.

MIU

MIU is an abbreviation for the tests Moisture, Insoluble Impurities and Unsaponifiable Matter. This value provides information about non-fat/oil components of food and feed grade fats and oils and is used primarily to screen incoming materials for industrial applications.

TITER

Titer is a measure of the hardness of fat. It is determined by melting the fat and then measuring the congealing temperature in degrees centigrade. The higher the titer value, the harder the fat is at room temperature.

RANCIDITY TESTING

Rancidity in food and feedstuff may result from oxidation of the lipid component of the sample, microbiological deterioration of the sample or both. Because the lack of a universally accepted definition of rancidity, no single rancidity test will meet every client's needs. Oils are said to become rancid when they undergo a degradation process known as oxidation. A variety of chemical compounds such as peroxides, aldehydes and free fatty acids are created as oil oxidizes. The tests that follow are those most frequently requested to monitor or predict oxidative degradation. 

• Active Oxygen Method (AOM) is a measure of the ability of a fat to resist oxidative rancidity during storage. An oil or fat is subjected to conditions known to accelerate degradation to help gauge the sample's resistance to oxidation. Oxygen is bubbled into a fat to cause oxidation of the fatty acids. The peroxide value test is used to monitor oxidation after the sample is stressed under controlled conditions for a long time or until a specific peroxide value is achieved.
• Free Fatty Acids (FFA) Fats and oils are primarily composed of various combinations of fatty acids bonded to a glycerine backbone. When fats and oils become rancid, individual fatty acids are "freed" and make the material slightly acidic. The FFA test measures this acidity and then expresses it on a fatty acid basis. The presence of high concentrations of free fatty acids in feed-grade fat, particularly "whole" animal fats may mean the fat is rancid. However, some fat sources such as acidulated soap stocks, can contain high amounts of free fatty acids without being rancid.
• Peroxide Value (PV) is the measure of the present state of rancidity of a sample. Also called Initial Peroxide Value (IPV) because it is determined on a sample as submitted. Fresh non-rancid fats have a low PV - usually less than 5. The PV of unstablized fat can change quickly. For this test, peroxides are indirectly measured under standardized conditions. The result is called the Peroxide Value, expressed as milliequivalents of peroxide per kilogram of fat.
• TBA Rancidity monitors certain types of aldehydes that form when a fat or oil oxidizes. These aldehydes react with 2-Thiobarbituric Acid (TBA) in the laboratory to form a complex that is easily measure

Eurofins Scientific, Inc. offers all of the tests listed above as well as the following lipid tests of interest to the animal and pet food industries:

• AOM Stability
• Color Tests (Lovibond, FAC)
• Flash Point
• Melting Point, Capillary
• Neutral Oil Los (NOL)
• Refining Loss
• Saponification Value
• Smoke Point
• Soap by Titration
• Solid Fat Index
• Total Fatty Acids