Some points in the analysis of meat extracts and allied preparations, with notes on their dietetic value : being the results of a series of analyses / performed by Professor Hugh Galt ... in the public health laboratory of Glasgow University during session 1898-99.

  • Galt, Hugh Miller.
Date:
1900-1901
Catalogue details

Licence: In copyright

Credit: Some points in the analysis of meat extracts and allied preparations, with notes on their dietetic value : being the results of a series of analyses / performed by Professor Hugh Galt ... in the public health laboratory of Glasgow University during session 1898-99. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    13/24 (page 9)
    lixiviated with repeated small quantities of hot distilled water. 5th, Fat. Any appreciable quantity of fat in a meat extract can only be regarded as an impurity qua the object intended, and we accord- ingly find that as a rule fat is present in extremely minute propor- tions, the one exception being Bovril. The percentage obtained in the case of Bovril is the average of analyses of three samples obtained from different sources. With regard to the method of estimation, some points are worthy of notice. On the advice of Professor Glaister, and accord- ing also to the method recommended by Allen,f I employed petroleum ether. I found, however, that even with the best re- distilled petroleum ether which could be obtained, it was impos- sible, using Soxhlet's apparatus to get the last portions of ether driven over by means of a water-bath, and I had finally to fall back on repeatedly exhausting the dry and powdered extract with petroleum ether, filtering and allowing the ether to spontaneously evaporate in a free current of air. This method gave very con- sistent results. On the other hand, when anhydrous sulphuric ether was employed, the results were invariably higher, and also fluctuated considerably. + 6th, Total Nitrogen. The most striking point here, is the close approximation of the percentages, the figures ranging from, roughly, seven to nine in the case of the pasty extracts, and from two and a half to three in the case of the liquid ones. For a long time the percentage of total nitrogen was looked upon more or less as an index of the food value of the preparation. This, of course, is erroneous. As previously pointed out, any real nutritive value in such preparations must be extremely small, and is entirely subservient to their value as animal stimulants. If it were certain that no extraneous matters were added, the total nitrogen present would have a certain value as indicating a larger or smaller proportion of nitrogen-containing meat bases, upon which the stimulant value of meat extracts depends. But for reasons already stated, the total solids may not be altogether * See Table on page G. f Commercial Organic Analysis, Vol. IV., p. 311. X Ether dissolves to some extent other constituents present.