Bread

BREAD, a food product obtained by baking leavened dough prepared from flour, water, and table salt, with or without the addition of malt, spices, sugar, milk, eggs, fats, etc., using leaven, yeast, or baking powders. In almost all countries of the world where cereal plants are cultivated or grain is imported, bread serves as the main basis of public nutrition. An exception to some extent is represented by China, Indochina, and Japan, where rice porridge is widely consumed among broad strata of the population, replacing bread. However, this exception is rather conventional, since the history of baking testifies that porridges and gruels (boiled cereal grains) are merely the prototype of modern baked bread. Evolution proceeded through the following stages: 1) raw cereal grains, 2) liquid gruels from cereal grains, 3) porridge from cereal grains, 4) baked flatbreads from unleavened bread dough ("azymes"), and 5) baked bread from leavened dough. In the USSR, the daily consumption norm of bread per person is 600-800 g for manual workers and 300-400 g for mental workers; in Western Europe and America, 250-500 g. These norms vary depending on local conditions, population habits, the consumer budget level, etc. In agrarian countries and in rural areas generally, bread consumption is higher than in cities. With the improvement of the material well-being of the population, the norm of bread consumption usually decreases due to the consumption of animal-derived food products. Taking into account the significant improvement in the material living conditions of the working people of the USSR by the end of the second five-year plan of socialist construction, it must be assumed that already in 1937 the consumption of bread and cereal products in major population centers of the USSR will decrease orientatively by 30% compared to the first five-year plan, while the consumption of meat, fish, eggs, milk, dairy products, fruits, and table vegetables will significantly increase. The wide distribution of bread as a food product is explained by its high nutritional value, pleasant taste, low cost, property of not becoming tiresome with daily consumption, and property of keeping for a long time without spoiling. Regarding the caloric content and chemical composition of bread, see Food products. Despite the high nutritional value of bread, it cannot be regarded as an ideal food product upon which one can subsist without consuming other food. Exclusive nutrition on bread has the following drawbacks: a) the proteins contained in bread (gliadin, glutenin) belong to the group of incomplete proteins, since they contain small amounts of such important amino acids as arginine, histidine, and lysine; b) bread contains a negligible amount of fat, which moreover is incomplete; c) bread is poor in vitamins, with vitamins C and B completely absent; d) the salt composition of bread cannot satisfy all the organism's needs for mineral substances. The most palatable, porous, soft, and slow-staling bread is prepared from wheat and rye flour. These types of flour contain the protein substance gluten (kleber), which yields a viscous dough that rises well during fermentation. Oatmeal, barley, corn, buckwheat, pea, and other types of flour do not contain gluten, and bread made from them is of less satisfactory quality, less loose, easily crumbly, and stales quickly. An admixture of 10-15% of other types of flour to wheat and rye flour already noticeably worsens the taste and physical properties of bread. Good-quality bread must be well baked throughout the entire thickness of the loaf. The upper crust of rye bread must be dark brown in color, and of wheat bread, light or dark yellow; it must be free of cracks, have no burnt spots, not separate from the crumb, and its thickness must not exceed 0.4-0.5 cm. The lower crust must not contain ash and coals. The bread crumb must be finely porous and elastic; it should not contain any heaviness (zakal)—a solid layer devoid of pores, especially near the lower crust. The presence of heaviness usually indicates either poor baking of bread or too high a water content, which was added in excess to the flour when kneading the dough in order to obtain a greater yield of bread. The increase in the weight of bread compared to the weight of flour taken for baking is called the bake-loss/gain (pripek). From 100 g of good-quality flour, 130-150 g of bread is obtained, i.e., the gain is 30-50%. The percentage of gain is allowed to be greater the drier, fresher, and richer in gluten the flour used for baking is. The taste and smell of bread must be pleasant, characteristic of a fresh product. A musty or bitter taste in bread usually indicates its manufacture from substandard flour or the spoilage of bread from irrational storage in damp, poorly ventilated rooms (development of molds in bread, etc.). When chewed, bread must not crunch on the teeth due to an admixture of sand and other mineral impurities. Bread should be released from the bakery no earlier than 4 hours after baking, because hot rye bread clumps during eating into dense lumps that are poorly digested and can cause digestive disorders. All-Union standards distinguish two main varieties of rye bread: a) from rye whole-grain flour (OST 517) and b) from rye sifted flour of 87% yield (OST 2473). Whole-grain flour bread is subdivided into two grades: ordinary and scalded (zavarnoy). For wheat bread, there are three standards: 1) simple wheat bread from single-milled flour of 95-96% yield (OST 518), 2) wheat bread from single-milled flour of 85% yield (OST 2474), 3) wheat bread from a mixture of single-milled flour of 85% yield in an amount of 60% and single-milled flour of 75% yield in an amount of 40% (OST 2475). In addition to standard varieties, higher grades of bread are often found on sale, manufactured according to special recipes and bearing special names. These include, for example: a) rye Borodino bread (dark brown crumb, delicate sweet-sour taste with a hint of malt); b) peklevanniy bread (light color, loose, coarsely porous, slightly sour, baked from very finely milled rye flour with a small addition of malt); c) Riga bread (a variety of peklevanniy bread, very firm crumb, finely porous, aromatic smell from the addition of caraway or anise, stales slowly); d) French roll—small sizes (200-1,000 g) and characteristic long shape of bread from the highest grade of wheat flour with the addition of sugar and rich ingredients—milk, butter, eggs, etc. Regarding moisture, porosity, acidity, and the content of insoluble mineral substances, All-Union standards impose the following requirements on bread (see table). The content of nutrients in bread and caloric value vary depending on the type and variety of bread and the method of its manufacture (see also Food products). Good-quality bread that satisfies the above standard requirements is well tolerated and easily digested in the human gastrointestinal tract. Bread that is poorly prepared and badly baked is assimilated poorly and often causes dyspeptic disorders due to inherent shortcomings called defects. Defects of bread include: a) poor baking of the crumb, b) heaviness (zakal), c) low porosity, d) excessive acidity, e) flour layers, f) "mochka"—pieces of old bread soaked in water, which is often mixed into the flour during dough preparation. Baking rules permit the addition to the dough only of good-quality stale or unsuccessfully baked bread, provided it has not been in consumer use. Substantial defects of bread also include various accidental and intentional admixtures: a) sand, clay, b) straw, chaff, coarse bran, weed seeds, among which harmful ones are corn cockle, darnel, marsh cress, vetchling; ergot and smut should also be classified among harmful admixtures, the content of which must not exceed the limit norms established for flour (0.06%). Poisoning admixtures include salts of copper and zinc, with which substandard flour is sometimes flavored in order to improve its baking properties. The addition of potassium alum for the same purpose is considered unacceptable. Among the conditional defects of bread that worsen its taste but do not affect its nutritional value and digestibility is bread staling, which depends, according to Boutroux, on the hardening of the amylopectin contained in bread. When reheated, stale bread becomes soft, but soon stales again. Scalded bread stales slower than ordinary bread. There are experimental observations that bread prepared with a 0.5% agar-agar solution does not stale for a very long time. Spoilage of bread that makes it unfit for consumption is often caused by the proliferation in it of molds and bacteria originating from flour, water, air, and objects with which the bread was in contact. Abnormal changes occurring in bread under the influence of molds and bacteria are called bread diseases.

Of the molds affecting bread, the most important are: Penicillium glaucum (green mold), Aspergillus glaucus (green mold), Mucor mucedo (white mold), Oidium aureum (orange mold), and Rhizopus nigricans (black mold). Moldy bread has an unpleasant musty odor and taste, and is therefore considered a substandard product. The molds Oidium aureum and Rhizopus nigricans are classified as harmful to humans. Among the bacteria affecting bread, the most significant is Bacillus mesentericus vulgatus (potato bacterium), which causes slimy degeneration of the bread crumb. The disease manifests itself in the fact that the bread acquires an extremely unpleasant odor and taste, its crumb becomes slimy, and when broken, thin threads resembling cobwebs stretch from it. Bacillus mesentericus vulgatus enters bread from infected flour or utensils. The slimy disease is more common in hot summer weather; its development requires sufficient moisture in the bread and a storage period of at least 2 days at 15° and above. Low storage temperatures and high acidity of the bread hinder the development of the disease. Bread affected by the slimy disease can cause nausea, vomiting, and diarrhea. Sometimes a disease of wheat bread is observed, manifested by the appearance of red spots and streaks on the surface and inside the loaf due to the reproduction of Micrococcus prodigiosus. Such bread is harmless, but due to its abnormal appearance, it is considered substandard. Bread for the sick. When prescribing bread to sick people, the following should be kept in mind: 1) Wheat bread made from high grades of finely ground flour is tolerated much better by the gastrointestinal tract than bread made from coarsely ground wheat flour. Rye bread made from sifted flour, prepared with yeast, is tolerated no worse than wheat bread. 2) People not accustomed to the consumption of rye bread since childhood often tolerate it poorly, complaining of severe flatulence and bowel pain. The same is observed in people with a naturally weak neuromuscular apparatus of the intestine. 3) Bread that is poorly baked, insufficiently porous, with a dense layer (zakal), and with high acidity, even if prepared from very delicate grades of flour, causes dyspeptic symptoms and is therefore contraindicated in all diseases of the stomach and intestines. 4) Bran bread made from coarsely ground flour is contraindicated in gastric atony and any irritation of the mucous membrane of the stomach and intestines (catarrh, ulcer, etc.). 5) Slightly stale bread, slices of fresh bread toasted on both sides, and delicate rusks are tolerated better by the digestive organs of patients than fresh bread. 6) Rye bread has a greater juice-stimulating effect than wheat bread. 7) Increased acidity significantly enhances the juice-stimulating effect of bread. 8) With increased secretory activity of the stomach, the amount of bread in the patient's food ration should be limited. 9) Among special types of bread used in patient nutrition, the following are applied: a) "doctor's" bread made from wheat flour with added bran, prescribed for chronic constipation depending on sluggish intestinal musculature; b) bread for diabetics made from pure bran, baked from bran with the addition of rich dough and almonds, glutinous, or aleurone bread; c) bread for nephritics (sodium chloride-free); d) calcareous bread made from wheat flour with the addition of 5% calcium carbonate, prescribed for chronic diarrhea. Bread surrogates. Wherever bread serves as the staple food, the population becomes so accustomed to it that in times of shortage of rye and wheat flour, they strive to bake a sufficient amount of bread by resorting to various kinds of surrogates. Surrogate bread becomes most widespread in lean years among the starving population. According to their nutritional value and digestibility, surrogates can be divided into two categories: better and worse. The first, better category includes food products that are sometimes used even in normal times for making bread, e.g., flour from oats, barley, buckwheat, corn, etc.; various table vegetables can also be classed here: potatoes, carrots, turnips, pumpkins, cabbage, etc., which are mixed into the bread dough in the form of boiled mash. The addition of these substances significantly changes the taste of bread and lowers its nutritional value, but does not impart any properties harmful to the consumer. The second, worse category of surrogates includes oilseed press cake, acorns, seeds of goosefoot, field bindweed, camelina, corn cockle, etc. Although all these seeds are rich in nitrogenous substances and fat, they contain an enormous amount of crude fiber, which hinders their digestibility; moreover, most of them have an unpleasant taste, and some contain harmful substances. According to Popov's studies, the digestibility of bread containing a large admixture of goosefoot or field bindweed does not exceed 40-45%; the digestibility of bread made from pure goosefoot, according to Sulmenov, is only 29%. If the food shortage in famine-stricken areas reaches extremes, bread begins to be baked with an admixture of chaff, hay, straw, bark, roots, etc., sometimes with the addition of clay, chalk, chernozem. Such admixtures to bread have no nutritional value and only harm the human body, causing persistent digestive disorders and gradual exhaustion. The scheme of sanitary analysis of bread must take into account the requirements of all-Union standards for bread. The conclusion on the wholesomeness of bread is made primarily on the basis of appearance, taste, and odor of the bread, then on the basis of examining its porosity, acidity, moisture content, amount of sand, and foreign, especially harmful, impurities in it. In a more detailed analysis, the determination of proteins, fats, and carbohydrates (crude fiber separately) is carried out in the bread, and if necessary, microscopic and bacteriological examination of the bread is also resorted to.

I.

Ignatov.