Foods and Their Adulteration / Origin, Manufacture, and Composition of Food Products; Description of Common Adulterations, Food Standards, and National Food Laws and Regulations

BARLEY (Genus Hordeum).

In the United States barley is not used to any extent as human food. It has all the nutritive properties of the common cereals and may be considered as a food product, although its chief use is in the making of fermented beverages which will be described in full in the second volume.

Barley is cultivated chiefly in the northern and western portions of the United States and is similar to the oat in this respect, that when the grain is threshed by the ordinary process the first layer of chaff is not separated, and, therefore, it goes into the market unhulled. There are varieties of naked barley which are not much cultivated. The cultivated varieties (Hordeum sativum Pers.) belong practically to one species, although there are very many different varieties grown.

The character of barley best suited to malting will be discussed in the second volume.

Acreage and Yield of Barley.

—The area planted to barley in the United States and other statistical data relating thereto for the year 1906 are as follows:

Composition of a Typical Unhulled Barley.

—From a comparative study of a number of samples of American barley the following numbers are regarded as typical of the composition of the unhulled barley grown in the United States:

The important points brought out in the above data are that the percentage of fiber in the unhulled barley is less than one-half that of the unhulled oat, as stated further on, while the percentage of ether extract is only about one-half that of the unhulled oat, and the protein is also decidedly less than in the whole oat.

As has been stated, barley is not very generally used in this country for human food, but is used in this and other countries as an ingredient of soup.

Protein of Barley.

—The following protein compounds are found in barley in proportionate weight to the total weight of the seed:

As seen from the above table the most important of the soluble proteins is hordein, which in quantity is almost equal to the insoluble protein of the barley grain. The starch granules of barley are recognized by their distinctive shape and size, as revealed by the microscope. A typical microphotographic view of barley starch is shown in Fig. 22.

BUCKWHEAT (Polygonum fagopyrum L.).

Buckwheat

 is usually classed with the cereals, but botanically it does not belong to the order of true grasses to which the cereals belong.

Buckwheat is commonly grown in many parts of the United States, and its seed is highly prized for bread and cake making purposes. The buckwheat is ground and the outer black tough hull separated, and the flour is used chiefly for making hot breakfast cakes which are much prized throughout the country. Properly ground buckwheat flour has a more or less dark tint, due to fine particles of the outer envelope which escape the bolting process.

Acreage and Yield of Buckwheat.

—This crop is not grown in many states. New York, Pennsylvania, and Michigan produce the largest quantities. The statistical data for buckwheat grown in the United States in 1906 are as follows:

Composition of Buckwheat Flour.

—The composition of finely bolted buckwheat flour is as follows:

The above is the composition of a white flour more finely ground and bolted than is advisable for palatable purposes. In the grinding of the above flour the germ which contains a greater part of ether extract is eliminated and also a large quantity of the bodies rich in protein. The composition of a less highly refined flour and one which is more palatable and more nutritious is given in the following data:

Milling Process.

—In the preparation of the so-called highest grade of buckwheat flour, that is, that which is most carefully ground and thoroughly bolted, the process employed is as follows: During the process of milling the buckwheat grains pass to a receiving separator which removes all the coarse particles, stones, straws, etc., by means of a series of sieves. At the same time any dust which they contain is blown out by a current of air. The sifted grains pass next to the scouring machines, in which they are thoroughly scoured, cleaned, and polished. From these machines the grains pass to a separator containing magnets, by means of which any pieces of metal, in the form of nails, screws, pieces of wire, etc., are removed.

The grains next pass through a steam dryer for removing the greater portion of the water employed for the scouring. As soon as they are dry they are again treated to a blast of air, which removes any dirt, dust, or light particles which may have been detached during the process of drying. The grains next pass to the shelling rolls, where the greater part of the outer hulls is removed. This process is accomplished by means of an apparatus which is called a sieve scalper. After the separation of the outer hulls the residue of the material passes to a drying chamber, where the moisture is reduced to about 10 percent, thus insuring the keeping qualities of the flour. After drying the grains are ready for the rolls. After entering the rolls the process is practically the same as that which is employed in milling wheat, consisting of a series of breaks and reductions, with the attendant bolting and grading, and this process is prolonged until the flour is practically removed from the feed or middlings. The sifting cloths used in the bolting of buckwheat flour are somewhat coarser than those for wheat, and this allows some of the dark particles of the inner hulls to pass into the flour, which gives it a dark color on baking. It is quite possible to make a buckwheat flour as white as that from wheat, but in this country the public taste requires a darker product, so that the white flour does not readily sell. The requisite degree of darkness is secured by using bolting cloths which will allow a part of the inner hulls (middlings) to pass into the flour. Two grades of flour are generally produced—a whiter one in which finer cloths are used, and a darker flour made by using coarser bolting cloths, allowing larger quantities of middlings to pass through. The outer hulls which are first removed are used for fuel, although from their composition it is seen that they contain a large quantity of carbohydrates and might be very profitably used in connection with some highly nitrogenous food, such as cottonseed meal or flaxseed meal for feeding cattle. The middlings are used principally as cattle food, and especially by dairymen.

The above process, while it makes a white and fine-looking flour, is not to be compared with the meal made in the old-fashioned way of grinding between stones and separating the principal part of the outer hull by bolting. This old-fashioned flour is more nutritious, that is, it contains more fat and protein, has a greater fuel value, or in other words has a greater number of calories and makes a much more palatable cake than the fine modern flour.

Buckwheat Cakes.

—Buckwheat cakes are prepared from batter made by mixing buckwheat flour into a paste of the proper consistency, seeding it with yeast, and allowing it to remain in a moderately warm place until fermentation takes place. The proteins of buckwheat have some agglutinating power, and thus, when treated as above, make a cake capable of a considerable degree of aeration. Baking powders are often used as a substitute for yeast and permit of preparation in a few minutes instead of waiting for the fermentation above mentioned. The product made in this way cannot be considered so palatable or nutritious as the old-fashioned product. The batter is baked on a smooth hot iron or soapstone, polished and kept bright in order to prevent the sticking of the cake. The proper polishing of the iron is a better means of preventing sticking than greasing. The batter is poured over the smooth iron and is of a consistency to flatten out without help and to form a film over the baking iron, which produces a cake about one-fourth of an inch in thickness. The cake is to be turned as soon as the side in contact with the iron is brown. It is evident that in this baking process there can be no very profound change in the starch granules, but this does not appear to materially interfere with the digestibility of the product. Buckwheat cakes are eaten hot, usually with butter and sirup. Maple sirup, sorghum sirup, or cane sirup in a pure state are highly prized for use with buckwheat cakes. These sirups are both condimental and nutritious. Mixed sirups made of glucose, melted brown sugar, or molasses, or mixtures of all these bodies are more commonly furnished to the consumer than the pure sirup mentioned above. Honey is also used very extensively as a condimental flavor for cakes of this kind.

Adulterations.

—There is probably no bread or cake making material which is subjected to more extensive adulteration than buckwheat flour. Much of what is sold as buckwheat flour may be regarded as imitations of that substance. Mixtures of rye flour, Indian corn flour, wheat flour, and other ground cereals are used as a substitute for buckwheat. There can be no objection from the hygienic point of view to such substitutes but the use of these mixtures under the name of buckwheat can be regarded in no other light than as an unpardonable fraud.

Detection of Adulterations.

—There is rarely any mineral adulteration practiced with buckwheat flour and if so it is easily detected by incineration. Any content of ash, unless baking powder has been used, above 2 percent may be regarded with suspicion as indicating an admixture of some mineral substance. The cereal flours used for adulteration are readily detected by the microscope in the hands of an experienced observer. The field of the microscope has only to be compared with the microscopic appearance of genuine buckwheat starch in order to detect the added substance.

Buckwheat Starch.

—The microscopic appearance of buckwheat starch is shown in the accompanying figure. The granules of buckwheat starch are very characteristic. They consist of chains or groups of more or less angular granules with a well defined nucleus, and without rings or with very faint rings. The contour of buckwheat starch is more angular than that of any other common cereal with exception of maize and rice, and it is this and the relative size which enable the observer to distinguish it from other starches. The size of the granules is quite uniform, varying usually only from 10 to 15 microns[23] in diameter. In so far as the angular appearance is concerned the granules of buckwheat starch have a general resemblance to that of maize and rice and oats, but a comparison under the microscope of the three starches reveals lines of distinction which with a little practice would prevent the observer from drawing a false conclusion.

INDIAN CORN (Zea mays).

Next to wheat the most important cereal used as a human food in the United States is Indian corn. According to the magnitude of the crop, Indian corn is the leading cereal of the country. Statistical data on the production of Indian corn in the United States during 1906 are given in the following table:

Indian corn

 is universally employed as food throughout all parts of the country, but more especially in the South, where the daily dietary is rarely complete without one or more meals in which Indian corn is served in some form or other. Although it is grown much more extensively in the North than in the South, it is not so generally used as human food. Indian corn grows in all kinds of soil and produces, under favorable conditions, large yields in all parts of the country. It is the most important agricultural crop of many states, namely, Indiana, Illinois, Iowa, Missouri, and Kansas. It is planted in the late winter and spring in different parts of the country. The planting season varies from January in Florida to June in Maine and Minnesota and the earlier varieties will mature in 120 days.

Maize

 is a crop which requires an abundance of rainfall and a high temperature during the growing season. Maize is planted in rows about three and one-half feet apart and in hills of about the same distance apart, or it may be drilled between the rows so that one stalk grows a distance of about from nine inches to a foot from its fellows. It requires constant cultivation during the early period of its growth and a careful preparation of the seed bed. Good farmers give from four to seven cultivations to the growing crop. The field must be kept free of weeds and in good tilth to secure the best results.

Many hundreds of analyses of the maize kernel have been made, but a combination of them all in the following data may be regarded as typical of the Indian corn grown in this country.

The consideration of the above data shows that Indian corn is a ration in which the protein is rather low. In other words, the ratio of protein to the carbohydrates and fat is rather large. It is a food product which is particularly well suited to furnish heat and energy and support a high degree of muscular exertion. For this reason it is a food product which is particularly well adapted to men engaged in hard manual labor.

Varieties.

—There are many distinct varieties of Indian corn. Sturtevant has published a description of several hundred. These varieties are classified under various subspecies. The polymorphic species, Zea mays, according to Sturtevant, can be divided into a number of groups which, on account of their well defined and persistent characters, may be considered as presenting specific claims and may properly receive specific nomenclature. The grouping adopted is founded upon the internal structure of the kernel for cultivated varieties, and the presence of a husk to the kernel in the assumed aboriginal form. Hence Sturtevant offers the names Zea tunicata for the husk-kernel forms, Zea everta for the popcorn, Zea indurata for the flint corns, Zea indentata for the dent corns, Zea amylacea for the soft corns, and Zea saccharata for the sweet corns.

Argument in favor of the specific claims for these groups is based primarily on the convenience thus attained; secondarily, on the absence or rarity of intermediate or connecting forms, so far as present data extend, and also on the antiquity of the separation. It seems almost certain that in the order of evolution (excluding from consideration the puzzling sweet corn group) progress has been from the pops, through the flints and the dents, to the softs. Certainly the soft corns in some of their varieties present a kernel that is larger, softer, and less fitted to the struggle with natural conditions than is the kernel from any of the other groups. Yet soft corns are the prevailing form in the mummy burials of Peru and of our Southwestern states. The popcorn, on the contrary, has stronger regerminative powers than have the other groups, is better fitted to contend against natural vicissitudes, and is the kind that has been reported as found growing wild in Mexico under the name of Coyote corn, Zea canina Watts.

Some of these subdivisions may not be accepted by botanists, but they are convenient for purposes of description. The principal field varieties which are grown are the flint corn, Zea indurata, and the dent corn, Zea indentata.

POPCORN.

This variety of maize is used very largely in the United States as a delicacy, and with sugar and cream as a dessert. It is a hard, small-grained variety which has the property, when heated, of exploding with a very great enlargement of the starch grain, producing a soft and very delicate edible material which is highly prized.

In the raw popcorn the starch grains are packed together very closely within the cells. When popping begins there is an expanding of the starch grains, producing a cavity nearly circular in form in each grain. This causes a rupturing of the cell walls, though fragments are plainly visible in the early stages. In the fully expanded or popped kernel the starch grains have expanded until each is about half or two-thirds as large as the original cells of the endosperm. The cell walls in this stage are practically obliterated as far as detecting in a section is concerned. The exploding of the starch grains is influenced by the water content of the kernel. It must not be too wet nor too dry; about 10 or 12 percent is the proper content of moisture. These changes are beautifully shown in the accompanying microphotographs, Figs. 24, 25, and 26, by Mr. Howard, of the Bureau of Chemistry.

SWEET CORN.

This is a variety of maize which develops a high sugar content and is eaten while the starch is yet soft, in other words, in an unripe state. It is a food product of immense importance in the United States, although almost unknown in Europe. The content of sugar varies from 5 to 8 percent in the fresh, soft kernel. The sugar which is present in the kernel rapidly disappears after the husking or removal from the stalk. In order to secure the maximum sweetness the corn should be cooked and eaten as soon as possible after removal from the stalk. Where it is not possible to do this it should be placed in cold storage after removal from the stalk and remain unhusked until it is ready for cooking. Green corn is universally eaten hot. It is usually cooked by boiling in water, although it may also be roasted before the fire. It has a high food value, and the composition of the grains of fresh, soft, green corn is shown in the following table:

Composition of Fresh Green Indian Corn:

Maize Proteins.

—The proteins of maize are composed principally of two zeins. The two forms are differentiated by their behavior toward alcohol. The first form constitutes the zein soluble in alcohol and the second the zein insoluble in alcohol. There are two other proteins in maize existing in small quantities which have been named myosin and vitellin, respectively. There is also a third unnamed variety and small quantities of albumin.

Variation in Maize, under Different Climatic Conditions.

—It is possible that most of the varieties and subvarieties of maize are simply the existing standard varieties modified by changing environments. There are certain conditions of climate, soil, and distribution of rainfall which tend to produce a large, starchy, soft grain, while other conditions tend to produce a small, hard grain richer in protein. The variations of importance are those of the carbohydrates and the protein, which are complementary, since as the protein rises the carbohydrates fall in relative proportion. There is also a marked variation in the carbohydrates, due to variety and climatic conditions combined. It is, for instance, the increase of the sugar at the expense of the starch that produces the body known as sweet maize eaten in the green state, as already described. Even in the sweet variety the relative proportion of sugar varies in different localities and under different conditions of growth.

Early Varieties.

—There are certain varieties of maize which are of especial value on account of their early maturation. This is a property extremely valuable in the sweet variety of maize or that eaten in the green state, since it is important to get these varieties into the market as early as possible and to continue them as long as possible. This is secured by planting the early variety at as early date as possible and planting later maturing varieties at intervals thereafter. By the selection of varieties of different periods of maturing it is possible in the climate of Washington to offer green corn from neighboring fields on the market from July until the advent of a killing frost which is usually the last of October or first of November. This gives a period of nearly four months during which the green corn may be delivered to the local market. Further south the period of supply is longer.

Canned Corn.

—Immense quantities of green corn are grown for the purpose of canning in order to supply the market during the closed season. The canning industry for green corn is located chiefly in the north. In the eastern states the industry is of great importance, from Maryland to Maine. The northern-grown corns are often preferred as they are supposed to be sweeter and more palatable. In the central western states, northern Indiana, Michigan, Wisconsin, northern Illinois, and Iowa are the principal centers of the canning industry, although it is practised to a greater or less extent in almost all parts of the country.

Adulterations of Canned Corn.

—Unfortunately in the canning process of corn additions have been made to the product which are of an objectionable nature. Chief among these is the use of bleaching agents such as sulfur in the form of burnt sulfur or of sulfite or bisulfite of soda or potash. These bleaching agents impart to the corn a white color which some consumers prefer, but at the expense of introducing a substance which must be regarded as deleterious to health. Still more objectionable is the practice of using saccharin instead of sugar as a sweetening agent. Saccharin is a coal tar product which has an intense, sweet taste, very persistent, and when used alone becomes disagreeable. A very small quantity of it is sufficient to impart a very sweet taste to the canned corn at a much less expense than could be secured by using the pure sugar. This form of adulteration is extremely reprehensible both because it deceives the consumer and adds a substance which by most hygienists is regarded as prejudicial to health. The bleaching agent and the artificial sweetener are wholly unnecessary. The manufacturers of sweet corn are expected to use the best and freshest and sweetest materials and cannot be excused for tampering with them in any way which either produces deception or injury to health.

Sugar added to make an ordinary corn taste like sweet corn is to be regarded as an adulteration unless its use is noted on the label.

Maize starch is also often added to sweet corn at the time of canning and this practice can only be regarded as an adulteration.

Detection of Adulterations in Sweet Corn.—Test for Sulfurous Acid.

—To about 25 grams of the sample (with the addition of water, if necessary) placed in a 200-c.c. Erlenmeyer flask, add some pure zinc and several cubic centimeters of hydrochloric acid. In the presence of sulfites, hydrogen sulfid will be generated and may be tested for with lead paper. Traces of metallic sulfids are occasionally present in vegetables, and by the above test will indicate sulfites. Hence positive results obtained by this method should be verified by the distillation method.[24] It is always advisable to make the quantitative determination of sulfites, owing to the danger that the test may be due to traces of sulfids. A trace is not to be considered sufficient as indicating either a bleaching agent or a preservative.

Detection of Saccharin.

[25]—Add from 25 to 40 c.c. of water to about 20 grams of the sample; macerate and strain through muslin; acidify with 2 c.c. of sulfuric acid (1 to 3) and extract with ether. Separate the ether layer, allow the ether to evaporate spontaneously, and take up the residue with water. If saccharin be present its presence will be indicated by the sweet taste imparted to the water. To confirm this test add from one to two grams of sodium hydroxid, and place the dish in an oil bath. Maintain the temperature of the oil at 250° C. for 20 minutes, when the saccharin will be converted into salicylic acid. After cooling and acidifying with sulfuric acid, extract in the usual way and test for salicylic acid. This test, of course, presupposes the absence of salicylic acid in the original sample. If salicylic acid is present in the original sample it must be removed before making the test for saccharin.

Starch of Indian Corn.

—Maize starch has characteristics which enable it to be easily detected by the microscope. The granules of this starch are of a more uniform size than those of wheat and vary from 20 to 30 microns in diameter. Occasionally very much smaller granules occur which probably are more of the original size and which have been arrested in growth by the ripening of the grain. The granules of maize starch are more or less polyhedral in form with round angles. The only common cereal starch which they can be mistaken for is rice, but they are generally larger than the granules of rice. Under the microscope with ordinary light they give only the faintest sign of rings but show in most cases a well developed hilum, which is at times star-shaped or like an irregular cross, while at other times it has the appearance of a circular depression. The maize starch granular is a type of the angular, as the wheat is of the sphere or spheroid form. The characteristic appearance of maize starch kernels is shown in the accompanying Fig. 27. Viewed with polarized light the starch grains of Indian corn present deep, well marked crosses, which divide each grain into four distinct parts as shown in Fig. 28. It is interesting to note that the angularity of maize starch is greatly influenced by the hardness of the kernels from which the grains are taken. The hard varieties, such as popcorn, have very angular grains while those from soft varieties have a great many almost spherical forms.

Maize Flour (Corn Meal).

—Formerly the maize kernel was ground between stones, bolted to remove the bran, and the maize flour or corn meal thus produced used directly as a human food. Modern milling operations have changed the method of producing maize flour so that not only is the outer bran removed but also, to a large extent, the germ itself, thus diminishing the quantity of fat in the prepared meal. This is notably true of the maize flour which is prepared for exportation. Leaving in the flour such a large quantity of fat tends to produce rancidity during shipment. To avoid any change of a deleterious nature which the flour may undergo during shipment, it is also frequently kiln-dried before being sent to foreign shores and even when intended for domestic consumption at points remote from the mill.

While this preparation of maize flour is doubtless important for transportation purposes, it impairs the palatability and nutritive value of the product. It is advisable to continue to have the maize flour prepared in the old-fashioned way and sent directly into consumption.

Method of Preparation.

—One method of preparing the maize flour is as follows: The grains are broken into large pieces and dried with steam heat at a temperature of from 105° to 110° C. (221°-239° F.). The mass while still hot passes into a mill composed of two stones which revolve rapidly in opposite directions. The smaller portions of the meal, which have been reduced to a kind of gum by the high temperature, are separated by this process from the covering or the bran of the kernel. A small mass of the starchy matter leaves the mill in the form of small noodles, which are freed from any particles of bran by sifting. In this manner a mass is obtained which is quite free from fiber and fat.

The composition of maize meal prepared by the above process is as follows:

This method of preparing maize meal is not used to any extent in this country, but is said to be commonly employed in Germany.

Composition of Maize Flour.

—The color of maize flour depends upon the color of the corn from which it is produced,—it may be white or yellow. The starch granules when heated in water to 62.5° C. swell up and become deformed, except a few, usually the small ones, which resist the action of water at that temperature. The starch granules of maize flour under polarized light present a black cross, very marked and very distinct when the field is obscured. When viewed under polarized light with a selenite plate the starch grains of maize are colored red with a green cross or reciprocally, and this coloration is very brilliant.

As has already been said, the composition of Indian corn meal made by the old-fashioned method of grinding and removing only the bran is practically that of the whole grain itself.

The composition of degerminated maize meal (Indian corn flour) is shown by the following average data:

The above data show that the refined Indian corn meal has lost more than three-fourths of its fat, a large portion of its mineral matter, and also a very considerable proportion of its protein, due to the separation of the bran which is extremely rich in protein and the germ which is rich both in oil and protein. A mere glance at the data shows that this refined Indian corn meal is much less nutritious than the natural meal in so far as its content of tissue-forming bodies and its faculty to furnish heat and energy are concerned. In other words, the calories are very much lower than in the natural corn meal. This is another reason for urging our people to return to the consumption of the old-fashioned material.

The Adulteration of Indian Corn Meal.

—Owing to the cheapness of Indian corn in so far as is known there is no adulteration practiced. The refined Indian corn flour itself is sometimes used as an adulteration for buckwheat flour, wheat flour, and other cereal flours, but has not itself been subjected to adulteration.

Corn Bread (Indian Corn Bread).

—Corn bread is a very common diet among all classes of people in the southern states and also to a considerable extent in the north.

Owing to the lack of agglutinating powers of the nitrogenous constituents of Indian corn flour, corn bread cannot be aerated or raised, as is the case with wheat bread. It is often eaten in an unleavened state. It may be partially leavened by the usual agent, namely, yeast or a chemical baking powder. Two varieties of bread are very commonly used, namely, that made of white flour or meal and that made of yellow. There is apparently no difference in the nutritive values of these two kinds. Some consumers prefer the white loaf and some the yellow.

Composition of Indian Corn Bread.

—The composition of bread depends upon whether the whole grain flour is used from which only the coarse bran has been removed by bolting or whether the decorticated and degerminated meal is used. In the first case bread is made richer in fat and protein and in the second case richer in starch. In the bread will also be found the materials used in its preparation, namely, salt, lard or other fats, milk, yeast, or baking powder residues. The best bread is made from the freshly ground flour of the whole grain from which only the outer covering, namely, the coarse bran has been removed. As offered at many of our hotels and some private houses, corn bread has been so manipulated as to lose a large part of its palatability, without any compensating improvement of its nutritive properties.

OATS (Genus Avena).

This cereal is an important food product, being used very largely in Europe, especially in Scotland, and also very extensively in this country as human food. The chief use of oats is for cattle food, especially for horses. It is extraordinarily rich in its nutritive constituents and, therefore, is prized highly as a food in the building and restoration of nitrogen tissues, such as the muscles. The variety in common cultivation is Avena sativa L.

Oats are grown in almost every part of the United States, but chiefly in the northern and western portions. In the southern states the crop is planted in the late autumn or early winter. In the northern states it is chiefly a spring crop, being sown early in the spring as soon as the ground is in fair condition. The oat crop is one which requires a rather abundant and well-distributed rainfall. A spring drought is very detrimental to the growth of oats, much more so than wheat or rye. It is a crop which is well suited to be grown under irrigation.

There are many varieties of oats in cultivation, but in general characteristics they all correspond to one description. The husk adheres firmly to the grain, and when threshed the grain of a common variety of oat carries the first layer of husk or chaff with it. Oats, as bought in the market, therefore, consist not only of the kernel or grain but also of this outer, chaffy envelope. The magnitude of the crop in the United States is very great, but only an inconsiderable proportion of the whole is used for human food, and this chiefly in some form of oatmeal. The statistics of the crop grown in the United States during 1906 are given in the following table:

Ratio of Kernel to Hull.

—Numerous examinations of unhulled oats show that the average percentage of kernel to hull for 100 parts is as 73 to 27. In the oats grown in the western states the proportion of kernel is relatively higher and in the southern states lower.

In the analytical process if the hull or chaff is ground with the grain the proportion of fiber or crude cellulose is very considerably higher than in the class of cereals ground without the chaff. The mean composition of unhulled kernels of oats of American growth is represented by the following table:

A study of the above data shows that the flour of unhulled oats is rich in fat, fiber, and ash. The large percentage of fiber and ash is due to a great degree to the composition of the hulls or chaff. The fat or oil comes chiefly from the germ.

Composition of Hulled Oats.

—Inasmuch as the chaff is always separated from the oat flour when the latter is to be used for human food, the composition of the oat in the hulled state is of greater importance to the present purpose than in the unhulled condition. The means of 179 analyses show the hulled oats to have the following compositions:

The removal of the hulls, as is seen, and the partially dried condition of the grain in the above analysis increases the percentage of other ingredients. The protein and fat are especially large in quantity. Oatmeals may be regarded as the richest of the cereal flours, both in protein and in oil.

The Protein of Oat Kernels.

—There are three principal products in the oat kernels characterized by their different degrees of solubility, namely, protein soluble in alcohol, protein soluble in dilute salt solution, and protein soluble in alkali. The protein soluble in alcohol constitutes about 1.25 percent of the whole grain, the protein soluble in dilute salt solution about 1.5 percent, and the protein soluble in alkali the remainder, viz., 11.25 percent. The protein of oats has very little agglutinating power and, therefore, oat flour is not suitable for making bread, or rather it is very little used for that purpose.

Oat Products.

—As has been intimated before, the principal oat products, as far as food is concerned, are the various forms of oatmeal commonly classed as breakfast foods. These products are prepared in various forms of agglutination and physical texture but if made from genuine oats, as there is little cause for doubt, they have essentially the same composition and nutritive power. It is doubtful if there is any preparation of oatmeal any more nutritious or palatable than the plain oat grain properly cooked. The forms in which the oat products are offered to the public are perhaps more convenient for use and in some cases by reason of heating and preparation require less trouble, but otherwise they apparently have no advantage over the simple product.

The mean composition of a number of oat flour products is shown in the following table:

In the dry substance:

It is evident from the above average analysis that the products examined are made from the whole kernel without the removal of the germ but with a very careful removal of the hull and bran. The composition of these products compares very favorably with the typical composition of the kernel itself. These data show the high nutritive value of these oat products, both in respect of fat and protein.