Food products / Henry C. Sherman.

  • Sherman, Henry C. (Henry Clapp), 1875-1955.
Date:
1914
Catalogue details

Licence: In copyright

Credit: Food products / Henry C. Sherman. Source: Wellcome Collection.

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

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    From what has been said above it will be clear that the various digestible carbohydrates of the food, having been split by the digestive ferments to monosaccharide, are absorbed into the blood. Any surplus is stored temporarily in the form of glycogen, chiefly in the liver, though to some extent in the muscles. The glucose which circulates in the blood is burned in the muscles and other active tissues as fuel, the burned glu- cose being constantly replaced by new glucose derived from the stored glycogen so that under ordinary conditions the carbohy- drate of the food is entirely burned as fuel. When more carbo- hydrate is received than is burned, the surplus is stored as gly- cogen but only to a limited extent, the total amount of glycogen which the body can store being estimated at less than one pound or only about as much carbohydrate as might be contained in the food of one day. A surplus of carbohydrate, in addition to being stored as glycogen, may also be converted into fat, and this transformation of carbohydrate into fat can be carried on to a very large extent and with almost no loss of energy. The energy value of the body of average carbohydrate in the food is 4.0 Calories per gram, or 1814 Calories per pound. Organic acids. Some foods contain considerable quantities of organic acids or their salts. Oranges and lemons, for instance, are rich in citric acid; grapes contain potassium acid tartrate; apples and other fruits contain malic acid, and many fruits contain succinic acid. A few foods contain oxalic acid or oxalates, but these are probably of little food value. Fermented foods may contain appreciable quantities of lactic acid as in sauerkraut and sour milk, buttermilk, etc., or acetic acid as in vinegar. With the exception of oxalic acid, these organic acids appear to be very readily burned in the body and doubtless their energy is used in practically the same way as the energy of the carbohydrates. The fuel values of some of these acids have been determined as follows: acetic acid, 3.5 Calories per gram; citric acid, 2.5 Calories per gram; lactic acid, 3.7 Calories per gram; succinic acid, 3.0 Calories per gram; tartaric acid, 1.7 Calories per gram. While these values are somewhat lower than those of the carbo- hydrates, it is not uncommon in reckoning the fuel value of a food to count the organic acid as carbohydrate, especially as in routine analyses the acids