Food and drugs analysis

1897 The Analyst  
The sample is warmed gently with a few drops of fairly fresh oil of turpentine and an alcoholic solution of guaiacum added. The appearance of the well-known blue colour shows that the milk has not been boiled, and vice versd. E. H, L. The Detection of Horseflesh in Sausages, etc. H. Bremer. (Forsch. Bey., 1897, iv., 1-8.)-The various methods which serve for the detection of horseflesh are based either on the glycogen reaction or on an examination of the fat (see ANALYST abstracts, xix., 24 ;
more » ... acts, xix., 24 ; xx., 95 and 252 ; and xxi., 231). The author gives a summary of the work of others in this direction, and then describes his process, which consists in an examination of the intra-muscular fat. The meat preparation, from which all visible fat has been removed, is minced in a sausage-machine, and heated for about an hour on the water-bath with water. The fat rising to the surface is poured away with the water, and the flesh, after having been washed several times with hot water, is dried at 100" C. for twelve hours, and extracted for several hours with a petroleum spirit of low boiling-point. Part of the intra-muscular fat thus obtained is taken for the determination of the iodine number, refractive index, and Reichert-Meissl number, The remainder is saponified, the excess of alkali neutralized with acetic acid, and the alcohol evaporated on the water bath. The soap is dissolved in hot water, a hot solution of zinc acetate (1 part to 2 parts of fat) added, and the zinc soap washed with hot water and alcohol, pressed between filter-paper, and extracted with about ten times its volume of water-free ether for fifteen to thirty minutes under a reflux condenser. After cooling, the solution is filtered into a weighed flask, the ether evaporated, and the iodine number of the residue determined. Every precaution must be taken to prevent access of air during filtration and drying. The subjoined table gives the results obtained by this method :
doi:10.1039/an8972200104 fatcat:mvnarxqp7neqbpnmpy665n7wea