SUGARS, SIRUPS, AND CONFECTIONERY The cane sugar industry. Sugar refining. The beet sugar industry. Extent of the sugar industry. By-products of sugar FOOD ADJUNCTS AND UNCLASSIFIED FOOD MATERIALS THROUGH the food the body obtains the substances which enter into its structure, which yield energy for its activities, and which regulate the processes essential to life and health. Most articles of food contain water, as shown by the fact that they lose weight on drying. The dry residue consists mainly of combustible matters, but when these are burned off there usually remains some ash. The combustible portion of the food may comprise a variety of organic compounds, but in the great majority of staple foods nearly all of the organic matter is found to be comprised within three groups of substances the carbohydrates (such as the starches and sugars), the fats (such as those of butter, olive oil, corn oil, lard, and meat fat), and the proteins (such as the albumin of egg, the curd of milk or cheese, the muscle fiber of meat, the gluten of flour or bread). Meat extracts and many vegetables contain nitrogen compounds simpler than proteins, the so-called "nitrogenous extractives" or "nitrogenous nonproteins." In green vegetables and berries a small part of the organic material consists of coloring matters, resins, and waxes. In the main, however, the organic matter of food consists essentially of proteins, fats, and carbohydrates, and in the methods commonly used for the routine analysis of foods the minor organic constituents are apt to be ignored, all nitrogenous material being counted as protein; all material soluble in ether, as fat; and all other organic material, as carbohydrate. If we consider the composition of food materials in terms of elements rather than compounds, we find that the plant and animal tissues which we use as food are composed mainly of the same twelve chemical elements which chiefly compose the tissues of the body; namely, carbon, hydrogen, oxygen, nitrogen, sulphur, phosphorus, chlorine, sodium, potassium, calcium, magnesium, and iron. Iodine, fluorine, and probably silicon and manganese are also essential to the body and so must be supplied by the food; but the amounts of these latter elements are so small that they are usually scarcely measurable by the ordinary methods of food analysis. While the ash of foods is composed of relatively simple inorganic (mineral) compounds such as the chlorides, phosphates, sulphates, and carbonates of sodium, potassium, calcium, magnesium, and iron, it does not follow that these elements exist in the form of the same inorganic compounds in the food. In many cases the inorganic compounds found in the ash are to a large extent formed during the burning of the food, the base-forming elements having existed in combination with organic acids or with proteins, while the acid radicles may also have existed in organic combination or may have been formed by the oxidation of the sulphur, phosphorus, or carbon of the organic matter. The principal chemical elements of foods and the most important kinds of compounds in which they are found may therefore be summarized as follows: The ultimate composition of a food is its composition as expressed in terms of the chemical elements into which it might ultimately be resolved, carbon, hydrogen, oxygen, nitrogen, sulphur, etc. The proximate composition is the composition in terms of the compounds actually present-proteins, fats, carbohydrates, mineral salts, water. These five groups of compounds have sometimes been called the "proximate principles " of food, or the "five food principles." As a precaution against ambiguity this use of the term " principles " is now generally avoided, but there is frequent occasion to use the terms ultimate and "proximate" in speaking of the composition and analysis of foods and it is well to keep the exact chemical significances of these terms in mind. The word "proximate must not be confused with "approximate." Food materials and foodstuffs. The term " food materials " is |