Sugar

SUGAR, a carbohydrate of sweet taste, having wide distribution as a nutritional and flavoring substance. Of the various types of sugar, the greatest nutritional significance is held by: cane (sucrose, beet), grape (glucose, dextrose), fruit (fructose, levulose), malt (maltose), and milk (lactose). Grape and fruit sugar belong to the monosaccharides-hexoses C₆H₁₂O₆; cane, malt, and milk sugar belong to the disaccharides C₁₂H₂₂O₁₁, which in the human intestine under the action of enzymes are hydrolyzed and also convert into monosaccharides (see Glucose, Lactose, Maltose, etc.). From a hygienic point of view, the various types of sugar can be characterized as follows. Cane sugar (sucrose) has the widest distribution of all types of edible sugar. This is explained by its high taste qualities, good purification of market varieties, and great stability during storage. World consumption of cane sugar in 1930/31 amounted to 29.7 million tons, of which beet sugar accounted for 39.3%. In the USSR, sugar production for 1933 is determined at 13.5 million centners. Cane sugar is contained in many plants, e.g., in sugar cane, sorghum stalks, in the sap of birch, maple, certain palms, in sugar beet, carrots, melons, pineapples, etc. The highest percentage of it, and moreover without a significant admixture of glucose and other carbohydrates, is contained in the stalks of sugar cane (14-26%) and sorghum (8-19%), and in the roots of sugar beet (15-23%). From these latter plants, it is extracted by industrial means. In Europe, cane sugar was for a long time an imported colonial commodity, and only at the beginning of the 19th century in France, Germany, and Russia were the first attempts made to obtain it industrially from sugar beet. At present, beet sugar has displaced most of the colonial cane sugar from European markets. Sugar beet (Beta vulgaris L., varietas saccharina vel rapa), from which sugar is produced, is a herbaceous biennial plant with broad leaves and a large succulent root, weighing on average 0.5-1.5 kg. It differs from ordinary garden beet by greater succulence, sugar content, and the white color of the parenchyma. The juice of sugar beet contains up to 15-20 percent or more of sucrose, organic acids, protein substances, gum, mucus, raffinose, invert sugar, phosphoric acid salts, and other salts of K, Na, Ca, Mg, Fe, and other metals. These substances, taken together, are called "non-sugars." The production of sugar from sugar beet includes the following operations: 1) washing and cleaning the sugar beet (beets), 2) extracting the juice from the beets, 3) cleaning and clarifying the juice, 4) boiling down the juice, 5) obtaining raw sugar, and 6) refining the sugar. Cleaned of leaves and well washed in mechanical washers, the sugar beet is cut in large beet slicers into chips and loaded into diffusers—tall, very voluminous, vertically standing iron cylinders with tightly closing lids. The diffusers, numbering 6-16, are arranged one next to the other in the form of a battery, with the bottom of each diffuser connected by a pipe to the top of the next one. A current of water heated to 45-80° is passed through the diffusers, which sequentially passes from one section of the diffuser to another and extracts sugar, salts, and other water-soluble substances from the beet chips; the liquid exiting the last section of the diffuser is close to beet juice in sugar content. The leached chips are used for livestock feed, and the juice obtained from the diffuser undergoes special purification. The juice is boiled in an open boiler with the addition of 1.5-3% CaO by weight of the beet (defecation); in this process, protein substances are partly destroyed, partly coagulate and precipitate, and organic acids, iron, and magnesium are precipitated. After defecation, carbon dioxide is passed into the juice (saturation), which precipitates the excess lime and destroys the lime saccharate, converting it into pure sugar and insoluble calcium carbonate. Substances suspended in the juice and precipitates obtained during saturation are removed by filtration through cloth in filter presses or in special vacuum filters. For decolorization, the juice is treated with sulfurous anhydride, which has replaced the previously used filtration through bone charcoal. The juice purified by the indicated methods is boiled down into a thick syrup, often treated a second time with sulfurous gas, and enters vacuum apparatuses, where further thickening of the syrup and the separation of sugar crystals from it occur. The resulting crystalline mass (massecuite) is loaded into centrifuges, where it is freed from syrup, washed, steamed, and then enters drum or belt dryers for drying. The dried white crystals constitute the best quality granulated sugar. The mother syrup separated in the centrifuges again enters vacuum apparatuses for thickening, where a second crystallization massecuite is formed, from which second-run granulated sugar is obtained, yellowish in color, less pure than the first-run sugar. Granulated sugar from beet sugar factories partly goes for general consumption, and partly enters special refineries for the production of refined products. Here it is dissolved in hot water, cleaned in filter presses and boiled down in vacuum apparatuses, to which, during evaporation, the blue dye ultramarine is added to impart greater whiteness to the products. Refined sugar produced from sugar cane does not differ in any way from beet refined sugar. Raw sugar from sugar cane is characterized by a pleasant aromatic smell and taste due to the content of aromatic substances of the benzene and vanilla series; raw sugar from sugar beet, on the contrary, possesses an unpleasant smell and aftertaste. According to the requirements of the All-Union Standard (OST 394), granulated sugar from sugar beet must have a sweet taste without foreign aftertaste or smell; it must be white in color (only a faint yellowish tint is allowed), be dry to the touch, and not contain lumps of caked crystals or foreign impurities visible to the eye. Granulated sugar for supplier distribution points must have the following composition: pure sucrose, calculated on dry matter, not less than 99.7%; reducing substances not more than 0.05%; ash not more than 0.03%; moisture not more than 0.15%; mechanical impurities and foreign organic compounds, not counting reducing substances, not more than 0.22%. In retail sales, a reduction in sucrose content to 99.5% and an increase in moisture to 0.2% are permitted. Refined sugar from sugar beet (OST 395) must be hard, dry, colorless or with a bluish tint, clean, and without spots. It must have a sweet taste without any foreign aftertaste or smell. Refined sugar must completely dissolve in water at a weight ratio of sugar to water of 110:65; the solution of sugar in water must be transparent, colorless, and without any smell. The composition of refined sugar must be as follows: pure sucrose, calculated on dry matter, not less than 99.9%; moisture in whole loaves not more than 0.4%, in pieces not more than 0.3%; reducing substances not more than 0.05%; ultramarine not more than 0.001%. There should be no more than 15% fines in lump sugar. In the literature, cases of finding barium, zinc, strontium, lead, and other poisonous metals in beet sugar are described. These substances can be found in sugar if chemical agents containing poisonous metals were used during its manufacture for cleaning, clarification, decolorization, etc. In poor grades of granulated sugar, an excess of moisture, clay, river sand, lime, etc., are often found. Sugar in the form of powder is adulterated by the addition of potato flour, talc, gypsum, etc. Sugar stored for a long time in damp rooms gradually spoils. If protein substances were not completely removed from the sugar during defecation, molds can develop in it, causing inversion and decomposition of the sugar. A sign of decomposition is the appearance of a bad smell. If the mother liquor or waste molasses is stored for a long time in large vats at a sugar factory, sliming of these sugar products may occur due to bacterial infection with Leuconostoc (Leuconostoc mesenterioides, Streptococcus mesenterioides). The syrup in this case turns into a gummy mass consisting of lumps of overgrown Leuconostoc. The growth of this microbe on carrots is characteristic: first, cartilaginous, then sliming zoogloeae grow, the external appearance of which resembles mesentery, which is why the microbe received the name mesenterioides. Grape sugar is found in almost all sweet fruits, berries, and vegetables. It is obtained industrially from potato or corn starch by boiling with dilute sulfuric or hydrochloric acid; after boiling, the liquid is neutralized with calcium carbonate, passed through filter presses and charcoal filters, and boiled down in vacuum apparatuses to a concentration at which glucose crystals begin to separate. The thickened syrup is poured into flat boxes, where it crystallizes into solid slabs of white or yellowish color, which constitute unrefined grape sugar. The average composition of such sugar is as follows: glucose 60-70%, dextrin 5-20%, water 15-20%, mineral salts 0.2-0.7%.

To purify sugar from syrup, the sugar cakes are subjected to pressing in hydraulic presses. Pressed sugar contains from 85% glucose and significantly fewer foreign substances. Lower grades of grape sugar have a more or less clearly expressed yellowish color and often contain harmful impurities, for example, poisonous heavy metals, arsenic, etc. Such grades are not suitable for food and are used for technical purposes. Refined grape sugar is produced either by recrystallization of raw sugar or is obtained by the above-described method, but only from the best grades of potato or corn starch. The grape sugar obtained by this method is very pure and contains up to 99% glucose. The All-Union Standard (OST 208) distinguishes three grades of grape sugar: grade A—refined glucose or dextrose, grade B—food-grade glucose, grade C—technical glucose. Refined and food-grade glucose must have a sweet taste without an extraneous aftertaste; a slight bitterness is permissible. Refined glucose must not contain more than 10% moisture, not more than 0.1% ash, and not less than 99% reducing substances; in food-grade glucose, the amount of moisture is not standardized, ash is not more than 0.4%, and reducing substances are not less than 65%; in technical glucose, the amount of water is not standardized, ash is not more than 1%, and reducing substances are not less than 75%. Free mineral acids must not be contained in any grades; iron is permitted only in the form of traces. Refined and food-grade glucose must not contain zinc, copper, lead, arsenic, tin, or antimony. Grape sugar is 3–4 times less sweet than cane sugar and therefore is significantly inferior to it as a sweet flavoring substance; nevertheless, it finds wide application in the confectionery industry in the manufacture of candies, marmalade, 'fasting sugar,' jam, in glazing fruits, and in the fabrication of sweet syrups, liqueurs, and soft drinks. Fruit sugar (fructose) is found together with grape sugar in sweet fruits and honey. Industrially, it is obtained from inverted cane sugar. The syrup resulting from this process possesses a very high sweetness and in the confectionery business is often preferred to cane sugar; it is mainly used for the manufacture of artificial honey. Malt sugar is rarely found in plants, for example, in soybeans, nasturtium leaves, etc. Industrially, it is obtained by the saccharification of starch with amylolytic enzymes contained in malt diastase. The sweet taste of malt sugar is 2–3 times weaker than that of cane sugar; like glucose, it finds application in the confectionery industry as a substitute for cane sugar. In view of the fact that malt sugar is well tolerated by infants, it is often used in infant feeding to sweeten and increase the nutritional value of cow's milk diluted with water. In Germany, pediatricians prefer to use not pure malt sugar, but its preparations obtained through special processing: a) Soxhlet's nutrient sugar, b) Loeflund's nutrient maltose, etc. Milk sugar has nutritional significance only insofar as it is found in the milk of humans and animals. In pure form, it is obtained from sweet milk whey by evaporating it, whereby lactose crystals precipitate, which are purified by repeated crystallization. The taste of milk sugar is weakly sweet. In the artificial feeding of infants, it is often used to increase the nutritional value and sweeten cow's milk diluted with water. Heubner and Hoffmann advise diluting cow's milk with an equal amount of a 6% milk sugar solution; Filatov recommends using a 10% milk sugar solution, adding it to milk in an amount of one-third by volume. 'Fasting sugar' is a product of the confectionery industry. According to Orlov's research, it consists of a mixture of cane sugar, potato starch syrup, and aromatic and coloring substances. Due to the uncertainty of its composition, a wide scope is open for the adulteration of fasting sugar. Small-scale artisans often use technical glucose, harmful aromatic essences, unauthorized coal-tar dyes, and mix in chalk, gypsum, talc, etc.

N. Ignatov. Sugar played a major role in pharmaceutical preparations in the past, and there existed a large section of medicinal preparations and forms in which sugar was the main constituent. These included, in addition to the pharmacy sugars themselves (large-crystal sugar—Saccharum Candis, or Candium, milk sugar, grape sugar or glucose, invert sugar, starch syrup, and honey), a number of preparations: syrups, electuaries (mixtures of syrups with various medicines, very sweet and sticky liquids), lozenges (mixtures of syrups with mucilaginous decoctions or solutions), oxymels (mixtures of syrups or honey with vinegar—Oxymel simplex, or with extracts prepared with the help of vinegar), confections (Electuarium—a mixture of powders with syrup or honey), pulps (Pulpa—fruit or berry pulp with powdered sugar, and Roob—a mixture of a thick, unfiltered decoction with sugar), orgeats (Orgeade—true emulsions, e.g., almond, with a high sugar content, and Looch—a similar false emulsion, i.e., with the addition of an emulsifier), and many others. Special factories produced so-called confectionery medicinal forms: lozenges (both pressed tablets, e.g., peppermint, Pepermint, and cut pastilles, Pastillae, and poured or extruded discs, Rotulae, and troches, Trochisci), lozenges (sen-sen, 'maiden's skin'), hard candies, barley sugar, morsuli (products like roasted almonds or chocolate with nuts, with included particles of medicinal plants), medicinal chocolate (for example, laxative with phenolphthalein or similar), marmalade, biscuits (e.g., laxative biscuit with jalap resin), gingerbread, various candies with medicinal fillings, and many others. At the present time, syrups still remain; sugar serves for coating (dragee-making) tablets and pills both to improve their taste and to protect their composition from spoilage under the influence of external conditions. In homeopathic pharmacy, sugar granules (balls of various sizes) are used. Sugar, both beet and milk, serves as an inert excipient for powders, tablets, pills, etc.

I. Oberhard. Sugar as a nutrient medium. Sugar is used in bacteriological practice to improve the growth of certain types of microbes. Various types of sugars—monosaccharides or disaccharides—are added to ordinary meat-peptone media (broth, gelatin, agar). Most often, glucose, lactose, and sucrose are used. Sugars are added to finished media. Sterilization is performed at a temperature of 110° for 10–15 minutes. Repeated heating at high temperatures should be avoided, as they affect the composition of the sugar, turning it into caramel. It is recommended to use fractional sterilization of sugar media—3 days in a row at a temperature of 100°. The amount of sugar added to the media is equal to 0.5–2%. Increasing the percentage, as a rule, reflects poorly on the growth of the microbe. Sugar media are used for the isolation and cultivation of streptococci, enterococci, pneumococci, and anaerobic microbes (in the latter case, sugar is added to the media in an amount of 2%). The cultivation of fungi is carried out on special media (Sabouraud, etc.) with the addition of 4% glucose or maltose. The addition of sugar to special media (Martin, etc.) in various combinations and proportions affects toxin production, increasing the number of antigenic units. Differential media are built on the principle of the decomposition of sugars under the influence of one or another type of microbe. The acid formed during the decomposition of sugar changes the reaction of the medium, which is accounted for by the change in the indicator added to the medium, and thus allows for differentiation between individual microbes. For example, the Endo medium, widely used for the isolation and differentiation of bacteria of the typhoid group, contains lactose and a colorless compound of fuchsin with sodium sulfite. Lactose is intensively decomposed under the influence of the growth of *Bacterium coli*; the lactic acid formed during this process releases the fuchsin, and the colonies of *Bacterium coli* are colored red. Pathogenic representatives of the intestinal group do not possess the properties to decompose lactose, and their colonies remain colorless. Similar media include the media of Padlewski, Conradi-Drigalski, Rothberger (see Nutrient media), and Oldekop, etc. The liquid media of Barzikov and Hiss are based on the same principle. 1% sugar from both the group of mono- and disaccharides and from the group of tri- and polysaccharides is added to peptone water. Litmus tincture is used as an indicator. When differentiating anaerobic microbes, it is recommended to use concentrated and pre-sterilized sugar solutions, added before inoculation, 10 drops per test tube with 5 cm³ of peptone water. The method has the advantage that the sugars are not subjected to repeated heating during the mandatory boiling of the medium before the inoculation of anaerobic microbes.

Z. Baidakova.