Differentiating Animal And Vegetable Fats With Refractive Index Measurements

The varying composition of butter and magarine allows for them to be characterized by refractive index measurement. These measurements can thus also provide insight into their quality, as any change in their optimal composition will affect the refractive index and butyro value. Moreover, the quality of oils and fats or oil blends which are used in the production of margarine can be controlled by refractive index measurement.

International regulations such as the AOAC 921.08 "Index of Refraction of Oils and Fats" and the ISO 6320:200 "Animal and Vegetable Fats and Oils"demand the measurement of oils and fats either with an Abbe refractometer or with a butyro refractometer.