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

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

Chapter 50

RYE

This is the source of the principal supply of bread in many European countries, but is not extensively used in the United States except among our citizens of foreign birth. It is also extensively used for making whisky. Rye belongs to the genus Secale. Only one species (Secale cereale L.) is commonly cultivated, but this species has a great many different varieties or races. According to the time of sowing there are two great classes of rye, namely, that planted in the autumn or early winter and that planted in the early spring, generally known respectively as winter and spring rye. This is one of the hardiest of cereals, and grows well in all locations where wheat and other common cereals flourish. The area planted in rye in the United States in 1906 and the quantity harvested are given in the following table:

Acreage, 2,001,904

Yield per acre, 16.7 bushels

Production, 33,374,833 „

Price per bushel, 58.9 cents

Total value, 19,671,243 dollars

Composition of Rye.

—From a study of many hundreds of analyses of rye of American origin the following table may be given as approximating the composition of a typical American rye:

Weight of 100 kernels, 2.50 grams

Moisture, 10.50 percent

Ether extract, 1.50 „

Protein, 12.25 „

Fiber, 2.10 „

Starch and sugar, 71.75 „

Ash, 1.90 „

The percentage of moisture in American grown rye is usually less than that of European origin. The American rye, also, has smaller kernels as a rule than that of foreign growth. In the content of protein the American samples of rye are fully equivalent to those of foreign origin, and in their mean composition, except as noted above, do not differ greatly from that of standard varieties collected abroad.

Protein of Rye.

—As is the case with other cereals more than one nitrogenous constituent exists in the rye. Three of the principal ones have been separated and named as follows: leucosin, gliadin, and edestin. Other proteins belonging to the globulin, albumin, and proteose family are also found in small proportions. The gliadin of rye resembles in its chemical and physical properties the gliadin of wheat. There is, however, in the rye no protein compound corresponding to the glutenin of wheat, and, therefore, rye flour does not form a gluten similar in quality to that of wheat, although it comes more nearly doing so than any other cereal. The gliadin of rye is soluble in alcohol, the leucosin of rye is soluble in water, and the edestin is soluble in a salt solution.

In a typical sample of American rye there will be found about 5.16 percent of gliadin, 2.27 percent of edestin and proteose, 0.55 percent of leucosin, and 3.14 percent of protein soluble in salt solution.

Adulteration of Rye Flour.

—Rye flour is frequently adulterated by the admixture of flours of other cereals. Real rye flour is distinguished by the character of the starch granules, as shown in Fig. 31.

Rye starch grains are lenticular in form, and the largest grains are of about 50 microns diameter. They average somewhat larger than wheat starch grains and are characterized by many of the large grains having a fissure in the form of a slit, cross, or star, which is rare in wheat and barley. The rings and hilum are indistinctly seen in some of the grains.

Rye Bread.

—This bread may be made leavened or unleavened, since the analogy in the property of its protein to that of wheat renders the leavening of rye bread somewhat more easy of accomplishment than that of the other cereals, with the exception of wheat.

Rye bread made of pure rye flour has a dark color, sometimes almost black. It is often baked long in advance of the time of eating and keeps well, is highly nutritious, and is the staple bread of many European countries.

A partial rye flour bread is made by mixing rye flour with other flours, such as wheat, barley, Indian corn, etc., and this is the kind which is commonly used in this country and in many portions of Europe where the light-colored breads are preferred to the dark.

The large consumption of bread made from rye and Indian corn indicates that even if the supply of wheat should become limited there is no reason to fear a famine of bread. It would be easy to substitute bread made wholly or in part of Indian corn and rye for that made wholly of wheat and thus to supply practically any demand for bread which the increasing population of the earth may make.