It’s difficult to estimate the value of fruit in human nourishment. They are not only an important source of readily assimilable sugars, organic acids, vitamins, microelements and other substances; they also raise an availability of other nutrients, in particular, fibers.

It is known that some substances, vital to people, are concentrated basically in fruit and berries. These substances contribute also in prophylaxis of many diseases and have medical effects. For example, diaphoretic properties of raspberry, active influence of plums for work of intestines, antiscorbutic action of dog rose and black currant have been known for a long time.

For the last 20 years biochemical value of the majority of fruit and berry cultures, especially presence of vitamins - vital and essential noncontiguous organic compounds - in them have been investigated rather full.

By researches of professor L.I.Vigorov it was ascertained that from 15 vitamins necessary for people more than half are contained in fruit and berries. In apple, for example, there are 11 of them. Characteristics of the most important vitamins for people are given below.

Vitamin C (ascorbic acid) improves general well-being and promotes normal metabolism in an organism, strengthens resistibility to infectious diseases, contributes in recovery from feverish diseases (grippe, pneumonia, etc.), and is a unique means against scurvy.

Daily requirement for vitamin C is 75-100 mg. Its basic sources are fresh vegetables, fruit and berries, especially black currant, sea buckthorn, dog rose, apples, mountain ash. For reception of a daily norm of vitamin C it's enough to eat a handful of black currant or 2-3 hips of dog rose.

Unfortunately, the majority of vitamins collapse during a prolonged storage and thermal processing, and are oxidized under the action of some metals and oxygen of air. Vitamin C collapses more easily than others; thus, it’s uneasy to provide an organism with this vitamin, especially in spring. In a jam prepared even at short cooking (30-40 minutes), there is approximately only half of initial amount of the vitamin. Therefore in spring when the lack of vitamin C is especially appreciable, it is better to use the berries frayed with sugar (sea-buckthorn, currant, gooseberry, etc). Dog rose tincture is also useful: a table-spoon of dry fruits brewed with a glass of boiled water, gives an approximately daily norm of vitamin C and a complex of other vitamins.

Vitamin Р , or Р-active substances. A special important nutrition value of fruit and berries is that they contain Р-active substances, rare in other vegetative products. Р-active substances represent a group of the phenol compounds described by a biological action generality.

Here belong catechins, anthocyans, leucoanthocyans, flovanols, etc.

Vitamin Р increases durability and elasticity of blood vessels walls, has anti-virus and antimicrobic properties, contributes in reduction of negative consequences of radiation injuries and removing of harmful cancerogenic substances from an organism.

By researches it was found that people whose ration is poor with fruit suffer from lowered durability of blood vessels more often, they are more subject to catarrhal diseases, quickly get tired, have pains in feet, shoulders, etc. All these phenomena are connected to an organism lacking of vitamin Р that have both prophylactic, and medical value.

Vitamin Р is contained in the majority of fruit and berries, but those of them are of the greatest value in which there is also enough vitamin C. It became known that they are conjointly working (synergic), so that their useful properties are revealed in mutual combination. Here belong sea buckthorn, currant, dog rose, apple tree, and mountain ash.

Daily norm of Р-active substances is about 100 mg. 100 of black currant contain 1-2 daily prophylactic norms of vitamin C and 0,5 - 1,0 daily medical norm of vitamin Р. In 100 g of apples the amount of Р-active substances varies from 30 up to 300 mg. Many berry cultures (wild strawberry, raspberry, cherry, etc.) contain more vitamin Р in phaeochrous berries.

It also became clear that vitamin Р, as well as vitamin C, is preserved at moderate thermal processing, therefore jam making should not proceed for more than 30-40 minutes, and drying of fruit and berries is recommended at a temperature not above 60⁰ C. An indicator of good safety of vitamins in jam, dried fruit and other products is an absence of brown colour peculiar to percoct preserves. For example, good preservation of vitamins is specified by red colour of jam from red berries, pale yellow – of apple jam, cherry or red - of broths from dry black currant and raspberry, light yellow - of dry dog rose tincture.

Vitamin A. In fruit and berries there is only its predecessor - carotene, which turns to vitamin A only in an organism. It’s fat-soluble, therefore is assimilated only together with oils. Vitamin A contributes in maintenance of healthy condition of integuments and mucous membrane, protects from eye diseases, and raises organism resistibility to infections. Vitamin A is called “a vitamin of growth” as it is necessary, in particular, for the growth of bones.

The significant amount of carotene is contained in sea buckthorn, dog rose, mountain ash and other fruit with an orange pulp. It is important to note that red-fruit kinds of sea-buckthorn contain carotene up to 8-10 mg %, that is 2-3 times more than in yellow-fruit kinds. A daily norm of carotene, that equals 5-6 mg, is provided by 50-100 of the named berries. Carotene strongly collapses at long thermal processing and drying. It is better preserved in crude jams, pasteurized juices with pulp, mashed potatoes, and in frozen berries.

Vitamin Е (tocopherol). Its lack causes a muscle dystrophia, neurasthenia and amplifies cardiovascular and tubercular diseases. Vitamin Е contributes in better assimilating of vitamin A.

Daily requirement for vitamin Е is 20-25 mg. Unfortunately, in fruit and berries its content is insignificant - about 1 mg % in apple, pear, raspberry, currant, and cherry; 2-3 mg % in dog rose, mountain ash, and apricot. Sea buckthorn is the richest in vitamin Е - 6-12 mg % on average, and up to 20% in new oil-bearing kinds. Vitamin Е as well as vitamin A is fat-soluble, therefore a high content of oil in sea buckthorn determines an increased content of useful substances in it.

Vitamin К1 ( phyllo quinone ) contributes in normal turning of blood and healing of wounds, normalizes heart and liver activity, improves stomach and intestines peristalsis.

Daily requirement is 10 mg. The greatest amount of vitamin К1 is in sea buckthorn (1,0-1,5 mg in 100 g) that is due to high oil content in its berries. There is a little bit less of it in dog rose, mountain ash, and black currant - up to 1 mg %.

Vitamin В9 (folic acid). An organism lacking of it may suffer from haematogenic infringements, strengthening of malignant growths, early turning gray.

Unfortunately, vitamin В9 collapses almost completely at thermal processing and, notwithstanding it is contained in many foods, including vegetables (potatoes, cabbage, carrot, etc.), the necessity of processing them results in the vitamin losses. Therefore fruit and berries, as well as their preservations received without thermal processing, are one of the basic sources of vitamin В9.

The daily requirement of the vitamin is 0,5-1,0 mg. It’s mostly contained in wild strawberry, raspberry, cherry (0,3 - 0,5 mg %), at that the more ripe and more intensively painted berries are, the more vitamin В9 is contained in them.

Vitamin В2 (riboflavin) contributes in normal food assimilation, improves eyesight, protects from skin diseases. The lack of vitamin В2 causes metabolism breaking, anemia, nervous system disorders, and hair drop out.

The most part of fruit-berry cultures are poor in this vitamin. Exception is made for plum, dog rose and cherry. Approximately 300 g of plums give 0,5 mg of riboflavin, which makes a quarter of a daily norm. In dog rose its amount varies from 0,1 up to 0,3 mg %, in cherry - 0,1 mg % on average, that is approximately twice as more than in other fruit and berries.

It is necessary to emphasize that industrial synthesizing of vitaminic preparations does not reduce the value of fruit and berries as the  most valuable source of vitamins better assimilated by an organism due to the presence in them of a complex of biologically active substances among which a special role is played by pectins.

Pectins are jellylike substances included in cell walls of plants. They are practically non-digestible, however, they vigorously adsorb and deduce various toxins from an organism, as well as harmful salt heavy metals (lead, zinc, copper, cobalt, strontium, etc.). Moreover, pertinacious substances contribute in cholesterol reduction in blood, reduction of fats accumulation, healing of ulcerous diseases of stomach and intestines.

The majority of foods are deprived of pectins or are poor in them. Only some vegetables (carrot, swede, cabbage) and mainly fruits and berries are basic suppliers of pectins for people. Presence of pectins is easily found out by a gelatinous condition of a jam made from them. There are very many pectins in currant, quince, cherry, plum, gooseberry, etc. Juice, made from red currant, large-fruited hawthorn, viburnum and other berries turns quickly to dense jelly which after addition of sugar is possible to store for a long time without any risk of valuable nutrients loss. Pectins are well preserved in crude products, therefore, for example, apples keep identical value for detoxication (removal of poisonous compounds) during all year round.

People also get various organic acids mainly from vegetative food, especially from fruit and berries. Organic acids are a pancreas stimulus, they neutralize influence of harmful metabolism products, normalize digestion, and warn organism presenilation. The content of organic acids, sugars, aromatic and other substances determines taste and technological qualities of fruit and berries.

Mineral substances and microelements. Fruit and vegetables are also the best source of inorganic mineral substances and microelements normalizing vital activity of a human organism. As well as vitamins, each of these substances performs its specific functions, and an absence of one is not compensated by a surplus of the other. So, calcium forms part of bones; phosphorus is comprised in brain structure; iron - in blood and some respiratory enzymes; sodium, potassium and magnesium are necessary for normal activity of a heart muscle; magnesium stimulates intestines peristalsis, choleresis, water-salt metabolism, and contributes in arterial pressure lowering due to its vasodilating activity; cobalt is necessary for an organism to prevent leukemia; iodine - for normal thyroid gland functioning, etc.

Mineral substances and microelements are spent during vital activity of an organism; therefore their constant assimilation is necessary.

The greatest content of phosphorus, calcium and magnesium is marked in black currant and gooseberry; potassium - in plums, apples, apricots, gooseberry, and cherry; iron - in red currant, raspberry, gooseberry, cherry, and plums; cobalt – in raspberry, wild strawberry, apples; iodine - in chokeberry; manganese - in cranberry, cherry, shadberry; copper - in apples, pears, gooseberry, and wild strawberry.

All fruits and berries contain a plenty of water-sometimes up to 80-90 % of their lump. But this is unusually useful "water" as it contains all the same substances that regulate human vital activity (sugar, acids, mineral salt, soluble vitamins, etc.). This water affects favorably water-salt metabolism, it slakes thirst and, as against simple water, simultaneously promotes to remove superfluous liquid from an organism.

Thus, the information on nutrition value of fruit and berries result in the fact that they should be comprised in our food allowance all year round. As many of them are accessible only during summer-autumn period, it is possible to preserve various kinds of processed fruit and berries for daily consumption.