ii BUTTER 167 



The simplest way of course would be to mix some substance 

 with the margarine, which, without diminishing its value, could 

 easily be detected by a characteristic colour reaction (latent 

 coloration). Several of such additives have been proposed, 

 viz., sesame oil, phenolphthalein, starch, but the only one 

 that has been at all generally adopted is sesame oil, which was 

 first proposed by H. Bremer. 1 This substance can easily be 

 detected by the red colour which it gives with furfurol and 

 hydrochloric acid, a test due to Baudouin 2 and modified by 

 Villavecchia and Fabris. 3 All the countries which insist upon 

 the addition of easily distinguishable substances to margarine 

 prescribe sesame oil (Belgium starch as well). 



Sesame oil, which was first used for this purpose in 1897 in 

 Germany, is particularly suitable, because it can take the place 

 of other vegetable oils used in the manufacture of margarine. 

 The prescribed amount of sesame oil in margarine is 10 per 

 cent., and the oil must show the following reactions : If to a 

 mixture of 0'5 part by volume of sesame oil and 99*5 parts by 

 volume of cotton-seed oil or earth-nut oil there be added 100 

 parts of fuming hydrochloric acid (sp. gr. 1*19) and a few drops 

 of a 2 per cent, alcoholic solution of furfurol, the hydrochloric 

 acid below the layer of oil must show a distinct red colour. 

 The furfurol used in the test must be colourless. 



The details of this so-called Baudouin 's test are as follows : 

 5 c.c. of melted butter fat are violently shaken with O'l c.c. of an 

 alcoholic furfurol solution (1 part of colourless furfurol and 100 

 parts of absolute alcohol) and 10 c.c. of hydrochloric acid (sp. gr. 

 1'19). When the hydrochloric acid which separates out below 

 has a distinct red colour which does not quickly disappear, the 

 presence of sesame oil has been proved. Should there be any 

 colouring matter in the butter which would turn red in the 

 presence of hydrochloric acid, it must first be shaken with 

 hydrochloric acid (sp. gr. 1125) to free it from the colouring 

 matter. In certain cases it happens that when shaken with 

 hydrochloric acid Baudouin's test does not give any red 

 coloration, even though sesame oil be present. In doubtful 

 cases Fendler 4 proposes that a method employed by 



1 Milch- Zeitung, 1897, p. 210. 



2 Zeitschrift fiir das chemische Grossgewerbe, 1878, p. 711. 

 :{ Zetiachrylfiirangewandti Chemie, 1893, p. :><>:>. 



4 Chem. Kevm, Vol. \\\. 



