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upon the market. The old-time product of Liebig's extract belongs to the second class, in which we also find many of our best known brands. The liquid extracts are varied and numerous and their number is rapidly increasing. The amount of meat extractives in some of these liquid products is remarkably small, the quantity of solids in two or three cases being under 10 percent. Alcohol is sometimes met with in these liquid preparations. The meat powders are far less numerous than the extracts of the first two classes. They consist largely, if not entirely, of albuminoses and peptones in addition to some insoluble proteid matter.
KINDS OF PREPARATIONS.
Moreover, it is necessary to distinguish between a meat extract containing large amounts of stimulating amido-acids and relatively small percentages of albuminoses, peptones and insoluble proteid matter on the one hand, and, on the other hand, an extract, or, more properly, a meat product, which consists largely of albuminoses, peptones and insoluble matter and relatively small amounts of amido-acids. The food value of this last group of products is undoubtedly greater than that of the former group, but being sold as meat extracts, their value should be based on the amount of extractives they contain and not on their food value.
The value of the amido-bodies, such as the meat bases, as food, is of uncertain character, but we must admit, as in the case of alcohol, they can at least be burned and furnish energy to the body. Like alcohol, the value of meat extractives lies principally in their stimulating qualities. The active principles of tea and coffee are on a similar basis. As these simpler amido-bodies are the final links in the long chain of hydrolytic products of the proteid molecule prior to the complete resolution of that molecule into carbon dioxid, water, etc., it is readily seen that an ounce of meat extractives (the various amidobodies) represents a far larger amount of beef than an ounce of albuminoses does. The various protein bodies and amido-acids are closely interwoven and it is impossible to produce amido-acids without producing albuminoses and peptones. Consequently, every commercial meat extract must consist partly of albuminoses, peptones, etc. The best of our extracts on the market to-day contain about 50 percent of their total nitrogen in the form of meat base nitrogen. When an extract contains less than 5 percent of its nitrogen in the form of meat base nitrogen the term "extract" seems to be no longer applicable. It is evident that the product represents much less meat than an extract with 50 percent of its nitrogen in the form of meat base nitrogen, provided the total nitrogen in both cases is approximately equal.
The proteid matter coagulated by heating to boiling, as well as the proteid matter insoluble in cold water, are both undesirable factors in an extract of meat. As a rule, the lower the proportion of these constituents, the higher the character of the meat extract. The same thing holds true in regard to the presence of albuminoses and peptones.
The quantity of total nitrogen in the form of meat base nitrogen in the best extracts reaches 50 percent. In one of the poorest it is 3.82 percent. The food value of the latter product might be greater than that of the former, but its cost of manufacture and its stimulating value are much less.
Creatin figures are very interesting and of much value in determining the source and value of an extract. Creatin is the principal amido-body found in meat, consequently we expect to find it or creatinin, its hydrated form, in still larger quantities in meat extracts. In several cases which came under our notice where the extract acted suspiciously, the creatin values were nil, and in such cases grave doubts exist as to the source of the extract. Our best extracts give high creatin as well as high meat base figures.
The xanthin bases and ammonia nitrogen figures present a variety of problems. While the xanthin bases are desirable constituents, ammonia in any amount is not. It is questionable whether the ammonia figures obtained by the magnesium oxid method do not give too high results (W. D. Bigelow). Gelatine.-Gelatine is a substance obtained from the nitrogenous portions of bones, hide, horns, hoofs, connective tissue, tendons and other nitrogenous. matter of the animal. One of the principal constituents of these bodies is a substance known as collagen. When this is heated either under pressure or without pressure it is changed to gelatine. Glue is unrefined gelatine or impure gelatine to which usually some substance has been added to increase its holding power. A type of gelatine known as isinglass is made from the bladders of sturgeons.
The general process of manufacturing gelatine is as follows (Whipple, Technology Quarterly, Vol. XV, No. 2, June, 1902):
"The hide scraps are first macerated and subjected to the action of a solution of lime or caustic soda in pits for two or three weeks. This dissolves most of the blood and saponifies the fats. The excess of lime or soda is then largely removed by washing and the solution steamed to dissolve the gelatine, but an excess of heat is avoided. Sulfurous acid is used to bleach the gelatine. When of sufficient strength, the gelatine is allowed to harden in molds or on slabs, and is ultimately dried in sheets on wire nets. Bone gelatine is made in a somewhat similar manner. The bones are crushed, boiled, treated with hydrochloric acid, and the gelatine is dissolved as before, washed, bleached and dried in sheets. The process requires a number of weeks."
Gelatine is also made from bones, fresh as well as old, and from the residues of bones used in the manufacture of buttons. The thin slices of the bones are treated with acid until all the phosphate of lime is extracted. They are then treated with lime and the gelatinous residue is then dissolved in warm water and purified for use.
The use of gelatine as a food has of late years become very common. The ease with which it can be made into jellies, the consistence which
it gives to ice-cream and its general utility in the cuisine have made it deservedly popular. Gelatine is the product of some of the nitrogenous parts of the animal and should be made only from the edible parts thereof. It is particularly abundant in the tendinous portions of the animal and in the tissues about the head, from which a large part of edible gelatine is made. No portion of the animal which is filthy or unfit for food should ever enter into the composition of the gelatine. If the parts from which the gelatine are made are cured previous to manufacture they should be cured in a perfectly sanitary way, as carefully as any other part of the meat. There can be no objection to the use of gelatine made from these sanitary materials in foods of all kinds.
There is, however, a possibility that some of the gelatines on the market may be made from materials wholly unfit for food. The food law forbids the use of animal substances unfit for food either directly or indirectly. As an illustration of this condition of affairs I may call attention to the fact that a part of the gelatines sold in the United States are made from parts of animals slaughtered in South America. It is not known to the consumer in what conditions these parts are preserved and transported. They may be possibly packed with the hide and sent to Belgium or other countries in a filthy, putrid and abhorrent state and these parts be cut from the hides before they are sent to the tanneries and converted into gelatine and sold as edible gelatine. Such a possibility should not exist, and there is no danger of its existence with high class manufacturers. A part of the horns is also used for such purposes, which being of an inedible portion and unfit for food is not admissible, under the law, as a constituent of edible gelatine. All such materials should be excluded in the manufacture of such an important product. Further than this, it may be stated that the line of demarcation between gelatine and glue is not always as well drawn as it should be, and this is illustrated in the report that the gelatine and glue are manufactured in the same factory, and the same conditions of odor and insanitation which adhere to glue may attach themselves to the gelatine. Such a condition, of course, would be an exceptional case, but its possibility should be excluded. Under the food law only those forms of gelatine first described above can be legally made and sold for use in food.
Adulteration of Gelatine.—The adulterations of gelatine are such as those referred to above in the form of raw materials employed which are insanitary and unfit for food. In addition to this, bleaching agents, namely, sulfurous acid or sulfites and mineral acids, are often employed in the manufacture, portions of which may remain in the finished article. All of these substances must be regarded as adulterants and as insanitary and unsuitable to gelatine, and to that extent unfit for human consumption.
Presence of Tetanus in Commercial Gelatine.-The Public Health and Marine Hospital Service has investigated gelatine to determine whether or
not it may be infected with pathogenic germs. The conclusions of the investigation are as follows (Bulletin No. 9, Hygienic Laboratory):
"Seven samples of gelatine examined; one showed tetanus spores.
"Two samples showed an oval end-spore rod, whose identity was not proved, but, in stained specimens, it would be hard to distinguish from tetanus, if indeed not tetanus with diminished virulence.
"In tetanus investigations it is important to use freshly made bouillon, as the organism is apt not to germinate in bouillon over ten days old. The thermal death point of the organism isolated was found to be between twenty and thirty seconds at 100 degrees C.
"It is important, therefore, that gelatine to be used for injections should be boiled at least ten minutes on account of the variability of the thermal death point in different species of tetanus. Whether this amount of heating impairs in any way the hemostatic power of gelatine has not been settled, but in case it does it is believed that the danger from tetanus more than overbalances its therapeutic value.
"It is suggested that when, as in hospitals, there is likelihood of gelatine injections being used for hemostatic purposes the gelatine solution be sterilized by the fractional method on three successive days and kept ready for use in sterile containers."
From the data given above it is seen that gelatine may become infected and the material from which it is made for edible purposes should be healthful, sanitary and fit for food. It is not likely that tetanus germs would prove dangerous when taken into the stomach, but freedom from infection should be secured if possible. These investigations show the wisdom of the pure food law in forbidding the use of parts of animals unfit for food, whether manufactured or not, in the production of food products. It is evident that a sufficient quantity of fresh, sanitary material or material properly preserved can be obtained in this country or in other countries to supply the needs for edible gelatine without resorting to the use of inedible parts of hides, horns, hoofs and other waste and unfit portions of the animal.
Summary.-Above have been presented some of the principal meat foods, the analytical data which show their composition, the processes by means of which they are prepared and the principal methods, objectionable and otherwise, by which they are preserved.
Meat is a staple article of diet among almost all nations of men. The anatomical structure of the human animal indicates that his environment has adapted him to eating meats of all kinds. In other words, man is an omnivorous animal. He has been developed in an environment in which all kinds of meats and vegetables have ministered to his sustenance, and thus he is an omnivorous animal both by evolution and necessarily by heredity. That man can live and flourish without meat has been fully established by
experiments, but that man cannot be nourished by meat alone has likewise been fully established, so that if the human race were necessarily to be deprived either of animal or vegetable foods, it would be the animal food which must be sacrificed.
It is not the purpose of this manual to discuss the relative merits of vegetarianism as compared with the common diet of the human race. It may not be amiss, however, to say that probably in the United States especially, a larger quantity of meat is eaten than is either necessary or wholesome. The people of our country are better able to supply themselves with expensive foods than those of other countries, and of the common foods meats are far more expensive than cereals. The eating of larger quantities of cereals and smaller quantities of meat would probably be conducive both to economy and health. It appears to be certain that the meat eating of the future may not be regarded so much as a necessity as it has in the past, but that meats will be used more as condimental substances than as staple foods. In all meat, for instance, that costs 25 cents a pound, such as steaks, there is over one-third or a half of it which is inedible, so that the edible portion really costs double that amount. On the contrary, when a pound of flour or maize is purchased, the price of which is perhaps only one-eighth that of meat, the whole of it is edible. Thus, from the mere point of economy as well as of nutrition the superiority of cereals and other vegetable products is at once evident. On the one hand, a cereal is almost a complete food containing all the elements necessary to nutrition, and it costs only a few cents a pound. On the other hand, a steak or roast is only a partial food and it costs much more than cereals.
It is hoped that one purpose of this manual may be secured, namely, by showing the consumer the actual composition of the different kinds of food and their method of preparation he may be led in the selection of his food. to follow the dictates of science and economy to a certain extent rather than merely the impulse of taste. The eating of such large quantities of meat is merely a habit which often is developed in children through the carelessness and ignorance of parents, much to the detriment of the child as well as to his future health and activity. It is believed that if the true principles of the use of meat were properly inculcated a large saving in the energy of the wage earner as well as those in more affluent circumstances would be secured.
Sound principles of economy establish a better condition of health and lead to greater activity and fruitful labor.
TERRESTRIAL ANIMAL OILS.
Terrestrial animal oils are obtained directly from parts of the animals which yield, at ordinary temperature, a substance which remains liquid. The fats which are in the feet of the animals are usually more liquid than in any other part of the body, and hence the natural animal oils are derived