Reichert-Meissl number

The Reichert-Meißl number (also Wollny number ) is a key figure for characterizing fat in food analysis .

The Reichert-Meißl number indicates how much volatile, water-soluble fatty acids can be obtained from the fat by saponification . It consists in specifying the amount of 0.1 N sodium hydroxide solution in ml that is required to neutralize the volatile, water-soluble fatty acids distilled off from 5 g of fat . It is usually less than 1.

The number is particularly high for pure butter and can therefore be used to detect adulterations.

The number is named after the chemists Emil Reichert (1838–1894) and Emerich Meissl (1855–1905). Emil Reichert wanted to simplify Otto Hehner's method for determining volatile fatty acids on the one hand and make the results more reproducible on the other. His method was published in 1879. In the same year Emerich Meissl published an optimized version of Reichert's method, which should make the results even more precise.

Together with the Polenske number and the Kirschner number , the Reichert-Meissl number can be used to calculate the butterfat content in fat blends.

Individual evidence

^ E. Reichert: Simplified butter test according to Hehner's principle . In: Fresenius' magazine for analytical chemistry . tape 18 , no. 1 , December 1879, ISSN 0016-1152 , p. 68–73 , doi : 10.1007 / BF01345315 ( archive.org [accessed May 6, 2019]).
↑ E. Meiſsl: Meiſsl, investigations on clarified butter. In: Polytechnisches Journal . tape 233 , 1879, pp. 229–235 ( hu-berlin.de [accessed on May 6, 2019]).
^ Joint FAO / WHO Food Standards Program .: Codex Alimentarius . 2nd ed., Rev. Food and Agriculture Organization of the United Nations, Rome 1995, ISBN 92-5103762-0 ( fao.org [accessed May 6, 2019]).

[1] E. Reichert: Simplified butter test according to Hehner's principle . In: Fresenius' magazine for analytical chemistry . tape 18 , no. 1 , December 1879, ISSN 0016-1152 , p. 68–73 , doi : 10.1007 / BF01345315 ( archive.org [accessed May 6, 2019]).

[2] E. Meiſsl: Meiſsl, investigations on clarified butter. In: Polytechnisches Journal . tape 233 , 1879, pp. 229–235 ( hu-berlin.de [accessed on May 6, 2019]).

[3] Joint FAO / WHO Food Standards Program .: Codex Alimentarius . 2nd ed., Rev. Food and Agriculture Organization of the United Nations, Rome 1995, ISBN 92-5103762-0 ( fao.org [accessed May 6, 2019]).