Fruits

Fruits in the botanical sense represent the developed flower ovary after fertilization, containing seeds. In food hygiene, however, P. refers to a large number of specially cultivated fruits, false fruits, and berries, which due to their significant sugar content serve as foodstuffs, and due to their content of fruit acids, tannins, and aromatic substances, are classified as flavoring agents. P. also includes a number of other dried fruits and seeds rich in fat, protein, and starch (almonds, nuts, chestnuts), which serve for nutrition either by themselves or as additions to other foodstuffs. By structure, fruits are divided into 4 groups: 1. Pome (grain) fruits, consisting of the skin, fruit pulp, and a five-chambered capsule with seeds; the walls of the chambers are formed by a parchment-like membrane. Pome fruits include apples, pears, quince, rowan, medlar, hawthorn, and juneberry—all from the apple family. 2. Stone fruits, consisting of the skin, fruit pulp, and a stone-seed with a hard shell. Stone fruits from the almond family include apricots, peaches, plums (Hungarian plum, cherry plum, green gage, mirabelle, sloe, prunes, garden plum), cherries, and sweet cherries; from the Cornaceae family—cornelian cherry. 3. Berries-fruits in which seeds are embedded in juicy pulp, with neither stones nor parchment-like membranes around the seeds. Berries include: a) Fruits formed from the upper or lower ovary: from the Ampelideae family—grape; from the Grossulariaceae family—gooseberry, currant; from the Vaccinium family—lingonberry, blueberry, bilberry, cranberry; b) Fruits which by their external form resemble berries, but by their development and formation are complex fruits, as they consist of more or less fused together individual small juicy drupes: raspberry, blackberry, dewberry, cloudberry, bunchberry—from the rose family; c) False fruits, formed by the growth of the convex receptacle, which has turned into a fleshy body bearing fruitlets (small grains) on its surface; the small grains sitting on the surface of the berry represent small nuts, each containing a seed. Such false fruits include strawberry and wild strawberry—from the rose family. The fruits of mulberry and fig represent a multiple fruit. 4. Nuts-fruits covered with a dry woody shell, inside of which is an edible seed (see Nuts).-Usually for convenience of review, subtropical and tropical fruits are separated into a special group, which includes: 1. Citrus fruits (oranges, lemons, mandarins, kumquats, pomelos, citrons, etc.)—from the citrus family. 2. Pineapples—from the bromeliad family. 3. Bananas—from the banana family. 4. Fig (wine berries)—from the Moraceae family. 5. Dates—from the palm family. 6. Japanese persimmon—from the Ebenaceae family. The main mass of fruits consists of fruit pulp, which is covered with skin and contains seeds. The skin and seeds in fruits constitute a nutritionally worthless part, and when consuming fruits fresh and during processing in many cases they are discarded. The content of fruit pulp varies: from 64% (almonds) to 98.5% (strawberry). Fruit pulp consists mainly of parenchymal cells of round or oval shape, arranged next to each other in such a way that small air spaces remain between them. Each cell consists of a thin membrane, inside of which is protoplasm. The protoplasm does not fill the entire cell, but forms a thin layer lining the inner surface of the cell, and in the form of separate threads passes through the entire cell. Large spaces-vacuoles-filled with cell sap remain between the protoplasm threads. The cell walls consist of cellulose and hemicellulose. In unripe fruits, chlorophyll and starch grains are present in the plasma. The cell (fruit) juice, filling the vacuoles, represents an aqueous solution of mineral and organic substances. The qualitative composition of fruits is as follows (some of the substances mentioned are characteristic only of certain types of fruits): A. Insoluble substances: cellulose, hemicellulose, protopectin (pectose), insoluble nitrogenous substances, starch, insoluble mineral substances. B. Soluble substances (form the fruit juice): 1. Organic. Sugars: fructose, glucose, sucrose; polyhydric alcohols—mannitol, sorbitol, inositol; pentosans, pectin; acids: malic, citric, tartaric, formic, benzoic, salicylic; nitrogenous substances: proteins, amino acids, amides; fat; tannins; coloring substances; aromatic substances; enzymes; vitamins. 2. Inorganic. Acid salts: SO₃, P₂O₅, SiO₂, Br₂O₃; base salts: K₂O, Na₂O, CaO, MgO, Mn₃O₄, Fe₂O₃, Al₂O₃. C. Water.-The quantitative composition of fruits and berries varies not only depending on the type and variety of fruit, but even for the same variety depending on climatic, soil, meteorological and other conditions. Weather has a great influence on the composition of fruits. It has been established that sunlight and heat increase the sugar content and reduce acidity in apples. The size of the fruits also affects their composition: apples grown on the same tree contain more sugar and acids, the larger they are (Table 1).

Sugar is one of the most important components of fruits and berries as a food and flavoring substance. Its content varies between 0.5% (lemons) and 25% (grapes). Fruits and berries contain 3 types of sugar: fructose, glucose, and sucrose; the first two are contained in all fruits and berries, while sucrose is absent in some types of fruits, namely in grapes, red currant, cloudberry, bunchberry, and cornelian cherry. In pome fruits, fructose predominates quantitatively. Among tropical fruits, bananas contain the most sugar (up to 13.7% sucrose in ripe ones) and pineapples (8.6%). All citrus fruits contain sucrose, and even lemons contain up to 0.7% of it. Starch is contained in green unripe fruits (apples, pears, etc.) in large quantities, and at first, during the growth of the fruit, its amount increases, and then, during the ripening process, it decreases; during storage it completely disappears, turning into sugar under the influence of diastase. Berries contain very little starch even in an unripe state.¹ In ripe fruits, pectin substances are present (see). Under the influence of the enzyme pectase, found in fruit and other plant juices, pectin turns into jelly, gelatin. When

black...... Dried figs (without pits). Fresh blackberry....... » dried....... Fresh apples........ » dried . . . .-. . . 1,16 3,09 1,08 3/58 1,01 2,52 1,29 2,07 0,35 2,07 0,59 0,40 0,47 0,74 0,40 0,93 0,66 2,37 0,43 0,40 1,89 0,78 0,40 1,42 1,27 0,59 0,43 0,30 0,35 0,45 0,48 0,58 0,80 Г, 94 11,01 61,40 6,08 56,72 15,21 69,66 11,17 45,51 9,16 58,79 6,24 8,40 8,15 0,93 5,33 9,28 6,27 10,08 63,08 7,04 6,70 72,15 5,89 20,13 12,13 51,16 6,80 6,19 2,50 0,61 6,87 2,32 1,50 2,92 5,53 5,41 2,14 3,76 12,29 1,98 6,10 0,56 1,39 0,43 2,75 0,48 1,66 0,52 1,63 ' 0,29 1,67 1,82 0,20 0,41 0,49-0,58 0,71 1,46 0,74 0,41 1,83 1,02 2,48 0,42 1,59 84,15 32,42 '84,26 28,78 79,12 24,46 80,57 49,88 83,83 29,41 86,99 88,90 85,61 82,64 85,12 82,96 82,78 28,07 85,48 81.31 18,51 78,36 9,11 84,37 31,28 0,81 2,16 0,76' 2,51 0,71 1,76 0,77 1,21 0,21 1,45 0,35 0,21 0,28 0,52 0,21 0,65 6,46 1,66 0,26 0,24 1,32 0,47 0,28 0,99 0,50 0,36 0,30 0,38 0,41 0,37 0,49 0,51 1,65 9,91 55,26 5,47 51,05 13,69 62,69 9,16 37,32 8,21 52,91 5,12 6,89 6,68 0,84 4,37 8,35 9,07 56,77 5,77 5,49 64,93 4,83 16,61 10,92 48,74 375 2 120 230 2 065 530 2 420 434 1585 315 2 030 170 365 330 2 185 255 2 765 415 1 975 so в action pectase from pectin methyl alcohol is cleaved off and pectic acid is formed. This explains the presence of methyl alcohol in fruit juices and wines; especially wines prepared from pomace contain a significant amount of methyl alcohol. During overripening of berries, pectin is also split by the action of pectase, which is why overripe, especially rotten berries contain methyl alcohol. The gel of pectin is soluble in water. According to F. Terevitinov and M. Bogomolova, in 100cm³ of juice from Russian F. the following pectin content (in grams) is found: apples- 0.43-1.20, Vladimir cherry-0.98, black currant-0.77, raspberry-1.22, cranberry- 1.30, strawberry-1.63, gooseberry-2.25.-The most common organic acids in F. are: malic, tartaric and citric. Malic is found in almost all F. It is absent only in citrus F. and cranberries. It predominates in apples and stone fruits. Citric acid-see Lemon. Tartaric acid is found in significant quantities only in grapes (0.21-0.74%). Benzoic acid has been found in lingonberry (0.08-0.22%) and cranberry (0.02-0.05%). Salicylic acid is found in small quantities in strawberry, raspberry and cherries.-Tannins in F. cause the astringent tart taste of certain F., and they are also responsible for the property of F. to quickly darken in the air when freshly broken or cut. This darkening is explained by the action of the enzyme tyrosinase (from the oxidase group) on tannins. Tyrosinase and tannins are contained in different cells.' When cut or otherwise mechanically damaged, these substances come into contact, and tyrosinase oxidizes the tannins with atmospheric oxygen, converting them into dark-colored flavenes. This also explains the spotting of apples under the skin, which is the result of pressure on the apple, during which the skin remains undamaged, but the flesh cells beneath it rupture.-The aroma of F. depends on the essential oils (see), which are contained mainly in the skin. The content of essential oils in F. is extremely small, with the exception of citrus fruits.-I ron in F., as in the plant organism in general, is found in the form of complex organic compounds. Forest strawberry, blueberry and grapevine are richest in iron. In percentage of ash weight - the iron content (calculated as Fe₂O₃) varies within such limits: pome fruits-0.2-1.2, stone fruits-0.3-1.0, berries-0.3-2.1. When spraying fruit trees to combat fungal diseases and pests, arsenic, lead and copper may get on the surface of F. Of these, only copper can be part of the normal composition of F. (up to 9 mg per 1 kg of air-dry substance of F.). According to American research, 1 kg of F. (on the American market) contains arsenic, lead and copper, (in mg): Table 2. Fruits Arsenic Lead Copper Lingonberry .... Grapes .... 0.02-0.94 0.09-3.90 0.02-7.10 0.3- 2.6 - 0.6-19.1 1.0-83.3 0.3-17.6 1.3- 6.4 On the vitamin content in fruits - see Vitamins. Fresh F. should be consumed in a ripe state. Overripe and rotten F. have poor taste qualities, and moreover their consumption can cause pathological phenomena of the gastrointestinal tract, since both contain methyl alcohol, and rotten ones contain products of the life activity of microorganisms. The harmful effect of unripe F. is usually exaggerated, since they contain the same components as ripe ones, but only in different ratios; no specific harmful substances are contained in them. Compared to ripe F., unripe ones contain more fiber, protopectin, starch, acids and less sugar and pectin. The increased content of protopectin determines the hardness of the cell walls of unripe F. When cooked, unripe F. are not dangerous. Individual representatives of F. Apples. The cultivated apple tree grows best in temperate and partly subtropical climates. In cold climates it freezes to death, in tropical climates it produces loose, mealy, overly sweet F. devoid of pleasant tartness. By time of ripening, apples are divided into 3 groups: summer, autumn, winter. Summer apples (White Naliv, Moscow and Revel Pear varieties, Arkad, Korobovka, Calville Blanc and others) ripen in August and can be kept after picking for no more than 1-2 months. Autumn (Titovka, Borovinka, Brown Striped and Pineapple, Calville Rouge and others) ripen on the tree in the first half of September, but acquire a pleasant taste after lying and remain fresh for 1¹/,- 3 months. Winter apples are harvested in late September and October' and to reach full ripeness must lie for 1-2 months. Many winter varieties, e.g. Renets, are unfit for eating at the time of picking from the tree due to the hardness and astringency of the flesh and acquire the proper qualities only after lying until December. Among winter varieties, the most widespread are Antonovka, Velvet Anise, Striped Anise, Aport, Babushkin, Dobry Krestyanin, Pepinka Litovskaya, Calville Blanc Winter, Kandily-Sin, Napoleon, Parmen Winter, White Rosemary, Renets and many others. Among winter varieties of the middle regions of the USSR, Antonovka has the greatest industrial importance. It is a good table variety and is irreplaceable for technical processing. This is the best material for drying, preparing marmalade, pastila, jelly, for pickling and winemaking and pectin production. Pears., Harvesting of pears is carried out according to the variety, weather, degree of exposure of the fruits to the sun and the age of the tree. Most summer and autumn varieties are picked significantly before full ripeness, since semi-ripe pears, having lain for several days in warmth, acquire a good taste and become juicy and soft, whereas if left to hang on the tree until fully ripe, they become dry, mealy and tasteless. On the contrary, winter varieties of pears are left on the tree as long as possible. Many varieties of pears are characterized by softening of the fruit flesh. This is a fermentative process accompanied by the disappearance of tannins and the appearance of ethyl alcohol, lactic and acetic acids.-Quince. F. the size of an apple, sometimes weighing up to 1kg. The tree is found in the wild in Bessarabia, Crimea, Transcaucasia and the foothills of the Caucasus. It is also cultivated in Uzbekistan. Quince in fresh form is little 60V fruits edible. Its main application is found in confectionery production and in the form of canned goods. According to Hotter, the average composition of quince (in %): water-81.90, sugars (total amount)-7.17, free acids (in malic acid)-0.93, tannins-0.065,, nitrogenous substances-0.57, fiber-1.87, ash-0.57. Some varieties of quince have a strong pleasant aroma due to enanthyl-ethyl and pelargonyl-ethyl ethers, which are contained in the skin of F.-L oquat has been cultivated for a long time in Europe. In the wild state it is distributed on the Black Sea coast of the Caucasus and to N. Persia. F. are small (about 15 g), like >apple. It is used both directly for eating and for various productions (pastila, marmalade, etc.).-Hawthorn-a shrub or small tree with small fruits of yellow, orange, red, dark color. It grows in N. America and, Yuy^. Europe. In Turkestan several species of hawnthorn grow wild, the ripe F. of which are eaten by local nomads. One species of hawthorn with F. in the form of small flattened apples the Kirghiz dry and prepare flour from it, from which they bake flatbreads and bread. It is also used as a tea surrogate.-Chokeberry-a shrub or small tree with small red or blackish fruits. It is found in North America, Europe and Asia. The fruits are sweet, suitable also for winemaking. Chokeberry gives good pastilas, jellies and pr. In dried form-a substitute for raisins. The homeland of apricot and peach trees is considered China, where the cultivation of these trees was known 3,000 years before our era. Apricots are distributed in Central Asia, India, S. Europe, in N. America and Ges. Africa.

In the USSR, apricots are cultivated in Ukraine, in Crimea, in the Caucasus, and in Turkestan. Two groups are distinguished: 1) apricots covered with fuzz, with mealy flesh; they are orange in color with a characteristic apricot aroma; 2) smooth-skinned apricots, with white flesh; they are distinguished by their sweet, juicy flesh and have a weak aroma. The bulk of apricots is consumed fresh. Many are dried both for home consumption and for industrial purposes. The dried apricot with the pit is called 'uryuk,' without the pit - 'kuraga.' The sweetest varieties of smooth-skinned apricots, dried, with skin and pits, yield 'sheptala.' When drying apricots without pits, a byproduct is obtained from the pit; the kernel is extracted from it, which is used in confectionery as an almond substitute.-Alycha (lycha, aladja) - a multi-stemmed tree or large shrub, distributed in the Caucasus. The fruit is the size of a small plum, green, yellow, red, or variegated, sweet, with an elongated pit. It is used for making jam, compotes, pastila, marmalade, jelly.-Thorn differs by its high content of tannins (up to 1.7%) and free acids (up to 1.65%) and therefore is inedible in its fresh state. After freezing, the amount of tannins and acids decreases, while the amount of sugars increases, and the thorn becomes sweeter, edible. There is a coating on the skin consisting of wax. The seeds contain amygdalin. It is used for making jam and in winemaking as an additive to fruit juices poor in tannins'. Grape. The number of grape varieties is more than 2,000. For characterizing a variety, the berry is of greatest importance. By color, berries are divided into 3 main categories: 1) black, i.e., with a dark red skin appearing black; 2) red, violet, representing different shades of red; 3) white, i.e., green, yellow, pinkish. The juice of white varieties and most black and red varieties is colorless; only some varieties of dark grape have colored juice. The normal number of seeds is 4, but 1-2 seeds are often found. The berries of some varieties contain no seeds. Grape varieties by use are divided into 3 groups: wine, table, and raisin. The grape skin is covered with a waxy coating, rich in tannins and contains tartar, calcium oxalate, nitrogenous and mineral substances, a small amount of sugar, traces of malic and tartaric acids, and coloring substances. The seeds of grape berries are rich in fat (4-19%) and tannins (1.8-8.0%). The amount of acid in grapes varies considerably and depends on the degree of ripeness and climatic conditions. The total acidity, calculated as tartaric acid in 100 cm³ of juice, ranges from 0.5 to 1.4. The sour taste of grapes depends mainly on malic acid and tartaric acid potassium salt (tartar). Strawberry and wild strawberry - perennial herbaceous plants. The following species are known: 1) wild strawberry, distributed throughout Europe, as well as in Asia and North America; 2) Virginia strawberry, found in many places in North America, with small bright red fruits; 3) Chilean strawberry with large yellowish-pink fruits. This species is the ancestor of most European varieties. All our cultural large-fruited varieties of strawberry are complex hybrids obtained from Chilean and Virginia strawberry; 4) wild strawberry; found in the wild in Central Europe. The fruits are larger than those of wild strawberry, fragrant. The main difference from strawberry is that wild strawberry is a dioecious plant and that in strawberries the berries easily separate from the calyx, whereas in wild strawberries the berries are firmly attached and hardly separate from the calyx. There are about 1,500 cultural varieties of strawberry.-Cranberry - a creeping semi-shrub with thread-like branches and small evergreen leaves; grows in wet peat bogs. Cranberry berries are initially white, then turn red and ripen in September. They are collected after the first frosts, when it becomes possible to approach the frozen bogs. The best variety is 'snowdrop' cranberry, i.e., one that has remained under the snow all winter and was collected in early spring. Fresh cranberry, due to its content of citric and benzoic acids, keeps well. Cranberry has great industrial significance and is used for preparing extract, for jam, for making juices, syrup, fruit drinks, kvass, and kissels. In North America, up to 20 varieties of large-fruited cranberry are cultivated. The homeland of citrus fruits is Southern and Eastern Asia, where they have been cultivated since ancient times; from there they spread to Persia, then to Southern Europe, and later to America. At present, they are cultivated in many countries of all parts of the world. In the USSR, the cultivation of citrus fruits is developing on the Black Sea coast of the Caucasus. Orange and lemon trees of medium size yield about 1,000 fruits per year, and with rational long-term cultivation, the yield is brought up to 2,000-3,000.-Oranges differ in fruit shape, color, and taste. Commercial varieties usually bear the name of the producing countries. Messina, Spanish, Jaffa, Alexandria, American varieties are known with yellow flesh, and Maltese and 'corolek' with sweet red flesh. The orange peel contains a large amount of essential oil (1.2-2.1%), which is obtained by pressing. Orange seeds, as well as those of other citrus fruits, contain a bitter nitrogen-free substance - limonin. The cultivation of lemon trees on the Black Sea coast of the Caucasus is hindered by their sensitivity to frost.-Kumquats - the sour fruits of Citrus japonica, round or egg-shaped, very small (about 9 g), with thin skin and many seeds. They are eaten with the skin. They are used for jam, glazing, and in the canning industry. They grow well in the Sukhumi-Sochi district. Composition (in %): water - 73.72, citric acid - 4.00; total sugar content 10.02. Pomelo (grapefruit, pomelo - from Latin Pomum melo); in America it is called 'grapefruit' because it grows in clusters of 4-12. Large fruits (about 300 g) with thick skin, without seeds. The fruit pulp has a sour taste and is eaten sprinkled with sugar. It is widely consumed in the USA. Contains about 3.14% citric acid and 3.12% sugar.-Citron (cedrat, ceddo) is cultivated in large quantities in Calabria and Sicily, from where it is exported for processing in pickled form. It grows well on the Black Sea coast of the Caucasus. Weight up to 300 g. It is not consumed fresh. It is used in confectionery production for candied fruits and filling in caramel. Contains about 4.82% citric acid, 2.07% sugar.-Pomegranates - the fruit of the pomegranate tree, growing wild in Minor and Central Asia, Persia, and Transcaucasia. It is cultivated in Central Asia, Transcaucasia, and throughout Southern Europe. The fruit is spherical with a hard shell, up to 12 cm in diameter, divided inside by partitions into two stories and several nests. In the nests are placed numerous seeds with a hard shell, covered with a thick, juicy, transparent edible purple or pinkish epithelium. Pomegranates are consumed fresh as a dessert fruit. Pressed pomegranate juice, boiled with sugar, yields syrup - grenadine. Composition (in %): water - 79.29, sugar - 11.64, fat - 1.15, nitrogenous substances - 1.17, free acids (mainly citric) - 0.77, fiber - 2.79, ash - 0.53.-Fig tree (fig, common fig) is cultivated in Minor Asia, Algeria, Italy, France, California, Chile, etc.; in the USSR - in Transcaucasia, Central Asia, and in the south of Crimea. Fresh fruits (figs, wine berries) are very tender, do not withstand further transportation and cannot be preserved, as they ferment easily. In fresh form, they are consumed only in places of growth. Drying is done in the sun (1-4 days). In the USSR, figs are not dried. Dried figs contain up to 51.43% sugar (mainly invert) and 0.71% free acids. Pineapple - the generic name for a group of perennial herbaceous plants of the bromeliad family. The false fruit, formed by the fusion of ovaries with the inflorescence axis and bracts, resembling a pine cone in shape, with a tuft of leaves at the top. It is distributed in all tropical countries, especially in the West Indies and Central America. In Europe, it is cultivated in greenhouses. The pineapple fruit weighs 1-4 kg, has a delicate sweet-sour taste and a pleasant aroma. It is consumed fresh and in large quantities goes for the production of canned goods and in confectionery production. Composition (in %): water - 85.83, sugar - 11.90, free acids (as sulfuric acid) - 0.60, nitrogenous substances - 0.42, ash - 0.40.-Banana - a large herbaceous plant, distributed throughout the tropical belt. The number of varieties is up to 2,000. Banana fruits have a bean-shaped, ribbed form, about 20 cm long and weighing up to 400 g. In the fruit bunch, up to 180 fruits are found. The fruit skin is thick, the flesh is tender, mealy, sweet. The average chemical composition of bananas (in %): water - 73.76, invert sugar - 10.78, sucrose - 8.88, starch - 2.27, nitrogenous substances - 1.33, fiber - 0.80, free acids (malic acid) - 0.38, fat - 0.25, ash - 0.89. The largest industrial banana plantations are in the tropical parts of Central and South America, from where bananas are exported to Europe by refrigerated ships.-Dates - the fruit of the date palm, growing in the deserts of Africa and Arabia. They are also cultivated in India and South.

In America. When gathered in the same bunch, there are ripe, semi-ripe and completely green F. Semi-ripe F. are eaten directly, unripe ones are exposed to the sun, where they ripen and dry out; ripe dates are dried in the sun until they become hard. Dates have an elongated-oval shape, up to 4-5 cm in length. The size and shape of F. depend on the variety of palm. Dried dates are covered with a shiny smooth reddish-yellow skin. The pulp is juicy and sweet. Inside lies a hard stone. The pulp of dried dates contains 62% sugar and 2.9-3.3% pentosans. Regarding nuts-see Nuts. In fresh state, with the exception of some apples and pears, F. cannot be preserved for long. During prolonged storage they wrinkle due to the evaporation of water. The main spoilage of F. depends on the development of molds in them (Penicillium glaucum, Aspergillus glaucus, Mucor racemosus, Rhizopus nigricans and others), yeasts that cause the decomposition of sugar in F. into alcohol and CO2, due to which F. acquire an alcoholic taste, and bacteria that cause rotting. Of the methods of preservation used, the simplest is drying F., but with this method F. lose their juiciness and softness, their taste and aroma suffer. Thus, dried F. cannot completely replace fresh ones. Pasteurization in hermetically sealed vessels better preserves the taste properties of F. More common methods of preserving F., or more precisely processing them, include preparing jams, jellies, preserves, fruit pastes, marmalades, etc., from F. Preservation here is ensured by boiling, during which the microorganisms present on the F. are killed, and the addition of a large amount of sugar creates conditions (high osmotic pressure) unfavorable for the development of microorganisms that get in after boiling. F. must be preserved as much as possible at low temperature (approx. 0°), the best degree of humidity in warehouses is 85-90% relative humidity. When F. are taken out of cold warehouses, it is necessary to bring them in the warehouse to the temperature of the external air; otherwise they become covered with condensation and can easily SPOIL.

M. Lukyanovich. The significance of F. in human nutrition is very great. The physiological effect of F. depends primarily on the state in which they are consumed. The most valuable are raw F. despite a number of side effects inherent in raw products, especially in excess and in the absence of habit to them, namely: a) sharp mechanical irritation of the digestive organs (by slag), which may cause diarrhea, b) sharp stimulation of gastric secretion and intestinal peristalsis (by organic acids), c) danger of microbial contamination, especially under unsanitary conditions of collection, storage and sale of F.; this danger is especially great during periods of epidemics of typhoid fever, cholera and dysentery; contamination can be largely eliminated by removing the skin (with clean hands), however many F. thereby lose most of their taste properties, so it is preferable to limit the disinfection of F. to washing in hot boiled water. The proposed methods of sterilizing raw F. (boiling on a sieve for 1 min., washing in chlorinated water or in a formalin solution) are little used, as they sharply affect the taste of F. During boiling and cooking F., softening of fiber and intercellular cementing substance occurs, as a result of which the mechanical irritation of the digestive organs decreases, but vitamins, salts and aromatic substances are largely destroyed, which reduces the nutritional and taste value of F. With rational processing, however, it is possible to preserve some vitamins and aromatic substances (heat in a small amount of water at a temperature not exceeding 70°, even better-stew in a closed vessel or heat with live steam). During ordinary cooking, a large amount of carbohydrates is removed from F., and proteins float to the surface in the form of foam, which should be preserved for eating. Indications for the use of F. in treatment are very extensive. F. constitute an essential part of any vegetarian diet. The addition of F. to mixed food is indicated especially because of their richness in slag (in constipation), vitamins (in various avitaminoses) and taste substances necessary in the diet of every patient. Nutrition with F. alone for a long time is not applicable with us due to their low caloric value and small protein content. Only in the tropics is full-fledged nutrition with F. achievable (e.g. from bananas and nuts). Instead, with us fruit days are widely used in medicine for the purpose: a) unloading the digestive organs (in diseases of metabolism and the liver), b) to restrict proteins in kidney diseases, especially in the pre-uremic periods (for 3-7 days), c) to save the body's own proteins and obtain an antitoxic effect in acute febrile diseases-by giving large amounts of fruit and berry juices (according to Noorden), d) to change the intestinal flora, mainly in putrefactive dyspepsias and colitis; Moro gives raw apples (100-300 g per portion, up to 1 kg per day) for children's colitis and diarrhea; in adults such apple days (600-800 g of raw sweet apples per day in the form of puree) often give a rapid therapeutic effect in chronic colitis (normalization of stool, cessation of frequent urges to defecate, reduction of meteorism, etc.). The therapeutic effect of raw fruits in diarrhea depends, in addition to the effect on the intestinal flora, also on the adsorbing action of pectin substances and tannic acid contained in the skin of apples and grapes. It is interesting to note that, despite the rich content of organic acids in apples, the amount of the latter in the feces, determined by Guaffon, after apple days not only does not increase, but even decreases in parallel with the decrease in ammonia, and not only in putrefactive forms of colitis, but also in fermentative forms (observations of Lorier). The reason may be that fruits are predominantly a 'base' diet (in the sense of Berg), as well as the fact that the organic acids of fruits are partially changed in the intestine, losing their chemical properties, e) In diabetes, apple days help to reduce acidosis and glycosuria. The reduction of acidosis after a fruit-rice diet is expressed in an increase in the alkaline reserve of the blood (Noorden). Finally, treatment with raw F. is widely used in scurvy (see), due to the high content of vitamin G in F., as well as in a number of other avitaminoses (see). Treatment with raw fruits together with vegetables and some dairy products and raw eggs is conducted mainly in diseases of the circulatory organs and kidney insufficiency. At the beginning of treatment, when there is a sudden transition from ordinary food, a significant loss of weight occurs, mainly due to the excretion of water and table salt, the amount of which in the urine falls to 0.5 g per day. The therapeutic effect, besides the reduction of edema, is expressed in the improvement of the subjective condition. Compared with the Carrel diet, this food has better digestibility and satiety property; it excellently quenches thirst despite the low water content. The therapeutic effect depends, besides the restriction of table salt, also on the richness in potassium and calcium and on the predominance of alkaline valences. The best effect, according to most authors, is achieved in peripheral edema, especially when digitalis and other therapeutic methods are ineffective. The effect on diuresis, edema and hypertension is clearly expressed in acute glomerulonephritis. In obesity, a good effect is observed mainly at the beginning of treatment. Contraindications are high temperature, intestinal disorders and aversion of the patient to F. (Eimer, Voit). Soft and ripe fruits are well tolerated also in achylia, except in cases complicated by enterocolitis; in the latter case fruit juices or periodic fruit days are prescribed. Of the individual types of fruit treatment, grape treatment (see) should be mentioned, lemon treatment, now used only in the form of prescribing raw juice in avitaminosis, treatment with blueberries in the form of decoctions and jellies in diarrhea, and the widespread use of nuts, chestnuts and almonds in the diet of diabetics.

i. lorie.