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
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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.

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    2nd, Total Solids. As fresh lean meat contains, roughly, 75 per cent, of water, it is evident that preparations losing more than this on evaporation contain less solid matter than ordinary meat, and can hardly be termed concentrated foods. On the other hand, a high percentage of total solids is no guarantee of high nutritive or even stimulant value; as the solids may and often do include a large relative proportion of sodium chloride. As to the estimation of the solids nothing need be said, as the figure follows from the loss on evaporation. 3rd, Ash. In the estimation of the ash great caution must be observed, else most discrepant results will be obtained. The heat must be very gentle at first so as to allow slow carbonization of the mass, thereafter increasing the heat very gradually so as to avoid partial volatilization of the chlorides. The operation should be conducted in the absence of any approach to a draught, and the ultimate weighing performed as rapidly as possible when the capsule is removed from the dessicator, as the ash is in all cases hygroscopic. It is often difficult to get the last of the black specks (which in- clude carbonaceous matter) converted into true ash, and the operation cannot be considered complete until the ash is of a uniform whitish-grey colour. The small percentage of ash relative to the total solids in Bovinine is noteworthy. 4th, Chlorides. The interest in the estimation of chlorides turns upon the ques- tion of added sodium chloride. A certain proportion of chlorides (mainly potassium chloride) is normally present in all such pre- parations, but it will be found that in most cases there are added chlorides, and as these are neither nutritive nor stimulant their presence in excess can only be regarded as an impurity, as they are added for preservative purposes merely. Further, sodium chloride taken in large excess is a cardiac depressant, and may even be actually poisonous unless a large excess of water is also taken. The following table shows the added chlorides (calculated as sodium chloride) present in the preparations examined :—reckon- ing -o6 per cent, for each 1 per cent, of total solids. * * Allen : Commercial Organic Analysis, Vol. IV.