Fat index

Example of a triglyceride in fat or oil. The fatty acid residue marked blue is saturated, the green marked is single, the red marked triple unsaturated . In the center, the triple esterified glycerine can be seen in black .

Fat indicators , also known as fat indicators, are used for quality control and characterization of fats and oils . The fat ratios are the results of analytical-chemical tests in the laboratory. An exact analytical determination of the content of individual glycerides is difficult and time-consuming, since the individual fats and oils usually consist of a large number of different glycerides, which have only slightly different structural formulas, since the fatty acid residues are similar to one another.

For this reason, in industry and trade, fats and oils are pragmatically characterized with fat indicators.

List of fat ratios

In specifications for fats and oils, exact analysis methods (often from the ASTM Books of Standards) and tolerance values ​​are specified for several grease indicators, depending on the area of ​​application of these substances. This is to ensure the suitability of the fats and oils for the intended use.

• specific weight
• Melting point (for fats) or freezing point (for oils), rarely sharp, usually an interval is observed
• Hardness (for fats) or viscosity (for oils)
• Refractive index
• Acid number (AN), also known as the neutralization number (NA)
• Saponification number (VZ)
• Ester number (EZ)
• Iodine number (IZ)
• Hydroxyl number (OHN)
• Peroxide number (POZ)
• Reichert-Meissl number (RMZ)
• Polenske number
• Rhod number (RhZ)
• Number of hens
• Carbonyl number
• Semi-micro butyric acid number
• Spread value
• Anisidine (ANZ)
• Totox number (sum of the peroxide number two and the anisidine number)

Monitoring compliance with the fat key figures is often a prerequisite for the release of individual batches of fats and oils in the oil mill . The industrial processors of the fats and oils determine the relevant grease indicators at the time of incoming goods and decide on their use, depending on the analysis results and compliance with the test tolerances.

Individual evidence

1. ^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag, Leipzig 1965, pp. 405-407.
2. ↑ Notes on determining the Totox number and the DGF standard methods C-VI 6a (02) and C-VI 6e (05) for determining the peroxide number and the anisidine number , German Society for Fat Science .

literature

• Jakob Lund: The relationships between the fat constants, magazine for food research and research , Volume 44, Number 3, 113–187, doi : 10.1007 / BF02038033 .