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AACC International Approved Methods -AACC Method 58-20.02. Refractive Index

AACC International Approved Methods

Special Properties of Fats, Oils, and Shortenings

AACCI Method 58-20.02
Refractive Index

VIEW METHOD

Objective
The refractive index of a substance is the ratio of speed of light in a vacuum to speed of light in the substance. For practical measurements, including this method, scales of standard instruments indicate refractive indexes with respect to air rather than vacuum. Index of refraction of oils is characteristic within certain limits for each kind of oil. It is related to degree of saturation but is affected by other factors such as free fatty acid content, oxidation, and heat treatment. The method determines the origin and quality of normal oils and liquid fats. This method is equivalent to Official Method Cc7-25 of the American Oil Chemists' Society (AOCS).