On the composition of food and how it is adulterated : with practical directions for its analysis / by W. Marcet.

  • Marcet, W. (William), 1828-1900.
Date:
1856
Catalogue details

Licence: Public Domain Mark

Credit: On the composition of food and how it is adulterated : with practical directions for its analysis / by W. Marcet. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    vious to its introduction into the test-case; moreover, this method is calculated to show rather the quality of the gluten than its quantity. The corn-chandlers and bakers, to determine the quality of their flour, make a sample into a paste with a little water, and draw it into a thread, or spread it out into a thin sheet with the thumb and index finger, and they judge of the quality of the dough from the length to which it may be drawn or spread out. The chemical composition of flour of the same kind may vary between certain limits, so that a shght increase or diminution of its constituents is not an indication of its being adulterated. Thus, Payne found the amount of gluten to vary in four varieties of wheat from nine to twenty- two per cent., and, what is of interest in reference to the bran, a diminution of gluten towards the internal part of the seed, so that the proportion of flour which remains in the bran is richest in gluten. Analogous results were obtained from Fiirstemberg in wheat bran. According to Dumas, the composition of wheat flour is as follows: Wheat Flour. Odessa flinty. Odessa soft. Water 10-00 12-00 10-00 Gluten 10-96 14-55 12-00 Starch 71-49 56-50 62-00 Sugar 4-72 8-48 7-36 Dextrine 3-32 4-90 5-81 100-49 96-43 97-17 The following is the mean between two analyses of the same flour which I performed in my laboratory : 100 parts of the dry flour contained— Starch ..... 82-043 Gluten ..... 8-950 Sugar ..... 5-200 Dextrine , . , . . 3-002 99-195