COMMON TEST METHODS AND RELATED TERMS

Iodine value (IV)

Measures via titration the degree of unsaturation of a fat or oil, expressed as grams of iodine absorbed per 100 g of oil or fat .  The values can be obtained using alternate methodology, such as FT-NIR spectroscopy, refractive index, or fatty acid composition by GC, or refractive index.

Cold test

The determination in time that an oil remains free of visible solids when immersed in a 32ºF ice-water bath.

Color, Lovibond

An analytical method used to quantify the visual color of an oil in units of red and yellow.

Dropping point

The temperature at which a solid fat softens to the point where it will flow and drop out of a specially designed container. The dropping point is an indication of the chemical and crystalline nature of the solid fat.

Fatty acid composition
(FAC)

Quantitative separation and determination by chain length of saturated, monounsaturated, polyunsaturated, and cis/ trans isomers from fatty acid methyl esters (FAMES) of fats and oils using gas (liquid) chromatography (GC/GLC) under specified conditions. 

Flavor

A sensory description experienced in taste testing of a fat or oil. A bland or neutral flavor is generally desirable.

Free fatty acid (FFA)

The amount of free fatty acids present in a fat or oil as determined by simple titration.

Melting point (MP)

The temperature at which a fat changes from solid to liquid within the specific parameters of the test.

Oil stability index (OSI)

An accelerated rancidity test that measures the rate of oxidation of a fat or oil and is expressed as an index number. The higher the index number, at a given temperature, the more stable the product is to oxidation. This method replaces the Active Oxygen Method (AOM).

Peroxide value (PV)

The determination of the extent of fat or oil oxidation by measuring the amount of peroxides present.

Solid fat index (SFI)

Provides an index or indication of the proportions of crystallized and molten fat at a given series of temperature checkpoints. Determined by measuring the dilatation  when a solid fat partially melts to liquid at the temperature of interest.

Solid fat content (SFC)

A measure of the crystallized fat content measured by magnetic resonance (NMR) at a series of temperature checkpoints. Determined by measuring the portion of hydrogen nuclei in solid phase over all hydrogen nuclei at the temperature of interest.

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