THE DIGESTIBILITY OF CHEESE.
As was stated above, cheese has been thought a cause of digestive disturbances, but work recently done by the Office of Experiment Stations, in cooperation with the Bureau of Animal Industry, and briefly summed up in a recent publication tends to disprove this.[10]
In the large number of experiments which were conducted, young men in good health were fed on a diet consisting of bread and fruit combined with American factory cheese which was made with different amounts of rennet and in different stages of ripening. The results showed that over 90 per cent of the nitrogenous material of the cheese was digested—that is, retained in the body—and nearly 90 per cent of the energy it supplied was available. In other words, cheese compares favorably with other foods in thoroughness of digestion—that is, in the percentage finally digested. Furthermore, it did not cause constipation or other physiological disturbances.
The above statement refers to full-cream cheese. Experiments made at the same time gave practically the same values for the digestibility of skim-milk cheese, of Swiss cheese, of Roquefort and Camembert cheese, and of cottage cheese.
Artificial digestion experiments made at the Minnesota Agricultural Experiment Station[11]indicate that cheese protein is digestedby the ferments of the intestines rather than by those of the stomach, and this is suggested as a reason for its reputation as a “hearty” food, the belief being that some foods which remain in the stomach longer than the average time, or are not digested by the stomach, are “hearty.” Cheese protein (casein) is intimately associated with fat, and there is experimental evidence to show that this condition has an effect upon the progress of digestion in the stomach.
The burning sensation or similar sensations sometimes experienced after eating certain sorts of cheese has been attributed to the presence of small amounts of free fatty acids.[12]It is commonly said that cheese is difficult to digest, the idea being that the body expends more labor in assimilating it than is required for other comparable foods. Experiments recently carried on by the Office of Experiment Stations in which the respiration calorimeter was used to study the energy expenditure during the period of active digestion, do not indicate that cheese differs materially in ease of digestion from a comparable amount of meat.[13]Uncooked full-cream cheese was used in these experiments. Another series recently begun by the Office of Experiment Stations with cooked cheese, though not yet sufficiently advanced to be conclusive, indicates that cheese thus eaten does not differ materially from raw cheese in this respect.
In connection with the use of cooked cheese in the diet, one fact should always be kept in mind. This is that, in common with all other fatty foods, cheese which has been overheated in cooking is likely to contain burned—that is, decomposed—fats. Disturbances from this cause, however, should be laid to poor cooking and not to the composition of this special food.
The use of potassium bicarbonate has often been recommended for increasing the digestibility of cheese, the amount suggested being a level teaspoonful to a pound of cheese. That the bicarbonate renders the cheese soluble in any appreciable degree, as has been claimed, is not apparent from a number of experiments which have been made. It does, however, neutralize some of the free fatty acids of the cheese, thus destroying some of the characteristic flavor. To some people this may be an advantage, but to others it would be counted a disadvantage.
FOOTNOTES:[10]U. S. Dept. Agr., Bur. Anim. Indus. Circ. 166.[11]Minnesota Sta. Bul. 74.[12]Hutchison’s “Food and the Principles of Dietetics,” London, 1901, p. 145.[13]U. S. Dept. Agr., An. Rpt. Sec. 1910, p. 149; Rpt. Office Expt. Stas. 1910, p. 35; Yearbook 1910, p. 359.
[10]U. S. Dept. Agr., Bur. Anim. Indus. Circ. 166.
[10]U. S. Dept. Agr., Bur. Anim. Indus. Circ. 166.
[11]Minnesota Sta. Bul. 74.
[11]Minnesota Sta. Bul. 74.
[12]Hutchison’s “Food and the Principles of Dietetics,” London, 1901, p. 145.
[12]Hutchison’s “Food and the Principles of Dietetics,” London, 1901, p. 145.
[13]U. S. Dept. Agr., An. Rpt. Sec. 1910, p. 149; Rpt. Office Expt. Stas. 1910, p. 35; Yearbook 1910, p. 359.
[13]U. S. Dept. Agr., An. Rpt. Sec. 1910, p. 149; Rpt. Office Expt. Stas. 1910, p. 35; Yearbook 1910, p. 359.