The analysis of food and drugs / by T.H. Pearmain and C.G. Moor.

  • Thomas Hames Pearmain
Date:
1897-1899
Catalogue details

Licence: Public Domain Mark

Credit: The analysis of food and drugs / by T.H. Pearmain and C.G. Moor. Source: Wellcome Collection.

    97/332 page 79
    the extreme dilution, the fat in the fluid produced averages for the whole seven only 0*96 per cent. The Analysis of Condensed Milk.—The analysis of con- densed milk should comprise estimations of the total solids, ash, proteids, milk-sugar and fat. The last four items added together and subtracted from the total solids will give the cane-sugar with fair accuracy. We have examined the ash of a number of milks for tin and lead, but they have been absent in every case. In examining any tinned article for tin or lead, great care must be taken to use a sharj^ tin- opener, or fragments of metal may be torn off and vitiate the result. The tin should be cut open and the contents should be thoroughly mixed, and 10 grammes weighed out, and made up to 100 c.c. We have now a 10 per cent, solution, which serves conveniently for the following estimations: Total Solids,—20 c.c. of the solution are evaporated in a platinum dish till constant in weight; this will take five or six hours. As]i.—The same quantity will serve for the determination of ash, and should be ignited at as low a temperature as possible. The ash in condensed milk varies, but on the average is somewhat over 2 per cent. Proteids. —10 c.c. of the solution are evaporated to dryness in an 8-ounce oxygen flask, and the nitrogen determined by the Kjeldhal process; the proteids are then calculated by the 6*3 factor. In May, 1893, Kichmond and Boseley read a paper before the Society of Public Analysts, entitled * Points in the Analysis of Condensed Milks,' in which they give methods for the estimation of the casein and the albumin, and point out some of the errors liable to occur in the use of Kitthausen's process for determining proteids. They recommend the Adams process for the extraction of the fat.
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