High resistance to manipulation thanks to the thick epidermis affects the durability of the fruit and easy transport.
Boxes or other large containers can be used for transportation, even over long distances. The fruit can be stored for up to two weeks at a temperature of 4 ° C and humidity of 80 to 85%, after which it must be deep-frozen and placed in a refrigerator where it can be stored for a long time. During the conservation period, the berries will rot and dry rather than rot. At low storage temperatures, losses are very small: after 1 month they amount to 0,5%, after 2 months 1,2%, and after 3 months 2%. Cold storage also has positive effects on the chemical composition of the fruit: the content of acids and tannins decreases, and the ratio of sugars and acids improves, which means that the berry loses its bitterness and becomes sweeter.
Fresh chokeberry fruits contain 17-28% of dry matter (Table 27). The content of total simple sugars changes: from 5-10% in fresh fruit it grows to the level of 35 to 43% in dried fruits. Only glucose and fructose make up 4,3-6,9% of fresh fruit weight, the rest is sucrose. The content of organic acids varies from 0,9 to 1,3%, so the ratio of sugars and acids of about 8 is very high. The fruits also contain a significant amount of pectin (0,3-0,7%), mostly in exocorps and are therefore suitable for the production of sweets and jellies, but also clear juices, due to the low content of pectin in the pulp.
However, the increased content of tannins and polyphenols, which contribute to the bitterness of the taste, makes the consumption of fresh fruits less convenient. Oszmiañski and Wojdylo (2005) examined the content of phenolic compounds and antioxidant activity of chokeberry fruit and found that polymerized proanthocyanidins, predominantly epicatechin, constitute an important class of polyphenolic compounds representing 66% of total polyphenols in the fruit. Anthocyanins form the second group of phenolic components with a share of 25%, with the most common glycosides of cyanidin: cyanidin 3-galactoside, cyanidin 3-glucoside, cyanidin 3-arabinoside and cyanidin 3-xyloside.
Among phenolic acids, the highest concentration of chlorogenic acid (3,02 mg / g of dry weight of fruit) was detected, which was higher in chokeberry juice than in porridge, which indicates good solubility in water. Quercetin derivatives (bound forms with different sugars) also participate with 1,3% in the content of total phenols. Slimestad et al (2005) point out that the flavonol content in chokeberry fruit exceeds the amount of 71 mg / g of fresh fruit weight.
Comparative review of anthocyanin content in chokeberry fruit and other berry fruits
In general, all the mentioned phenolic components are important as the most active antioxidants, contributing to the pronounced anticancer activity of the fruits of this fruit. Hagerman et al (1998) particularly emphasize the importance of tannins as much stronger antioxidant components compared to monomeric phenols.
Of the microelements in the chokeberry fruit, boron, fluorine, manganese, molybdenum, iron and iodine are present, of which the iodine content can be up to 40 mg% in dry matter.
In addition, the fruit contains many vitamins (vitamins C, P, B2, B6, E, PP, carotene, provitamin A). The content of vitamin C, according to various authors, varies from 10 to 28 mg / 100 g of fresh fruit weight, and is not too high compared to other small fruits (hawthorn - 50 mg, red currant - 40 mg, black currant - up to 300 mg per 100 d). The amount of vitamin C decreases with the degree of fruit ripeness: dried unripe fruits contain 103-122 mg / 100 g, fresh unripe fruits 22,5-32,5 mg / 100 g, and dried ripe fruits only 72-82 mg (Ciesielska, 2000 ).
Aronia is a rich source of vitamin P. It combines various molecules, such as flavones, anthocyanins, phenolic acids, catechol, coumarin derivatives and tannins. There are some difficulties in identifying these compounds and therefore there are pronounced oscillations in the determined values. Nevertheless, the content of vitamin P of 2.500-5.000 mg / 100 g in fresh fruits is significantly higher than in other fruits.
Aronia is commonly used in the food industry to make jams, jellies, clear juices and liqueurs. Due to the high content of anthocyanins in the fruit, these products have an intense red color, while a large amount of vitamin P makes this color very stable. Finally, the growing area under plantations of this fruit in the countries of Central Europe (Germany, Poland, Slovakia) and Russia, has encouraged the development of the processing industry and the creation of a large number of new food and pharmaceutical products.
The juice obtained by squeezing fresh chokeberry fruit is highly valued in both the processing and pharmaceutical industries. It contains 7-9% sugar, 0,8-1,1% organic acids, about 400 mg / 100 g of vitamin P, all the previously mentioned vitamins and minerals, as well as a certain amount of yeast and natural antibiotics. The share of juice in fresh product is about 75%, and in frozen fruits up to 80%. The clear juice no longer has the sour taste of fresh fruit - now it is an excellent refreshing drink with a characteristic aroma, mild taste and bright purple color. It is also used to prepare mixtures (eg with apple or strawberry juice), which are more aromatic and sweeter and which retain an intense color. Also, adding 5-7% of chokeberry juice to juices that are deficient in anthocyanins is enough to make their color attractive. The juice is also used in the production of carbonated drinks and ciders, by adding 1: 2 to apple puree.
Jam, jellies and purees are produced in the same way, using only chokeberry fruit or mixing different fruits. Chokeberry and apple jam, chokeberry and strawberry jam, chokeberry and raspberry jam are produced in Germany, Poland and Hungary. They are at a high price, because during the production there is no reduction in the amount of vitamin P. A candy fruit, intended for the confectionery industry, has a similar property. Chokeberry puree is used in the production of yogurt and dairy desserts, which give it an attractive color and taste.
Aronia is also used in the production of alcoholic beverages. The fruits can be subjected to fermentation, whereby about 100 l of alcohol with a strength of 4,2 ° is obtained from 100 kg of fruit. The obtained products are used to obtain liqueurs and aromatize vodka.
Due to the high content of anthocyanins, chokeberry fruit extract is used as a natural dye in the food industry. Even when diluted a hundred times, it retains a completely red-purple color. Chokeberry juice has more stable anthocyanins than the juice called, and thus less tendency to darken. About 80% of anthocyanins are located in the mesocarp. They are extracted without problems by treating the coma remaining in the production of juices with an aqueous solution of alcohol; one part can also be obtained by using hot water. It has been determined that frozen fruits contain almost twice as much anthocyanins as dried fruits, which means that these ingredients are lost during drying. Anthocyanin extraction must be performed on a wet chimney, within 3-4 days after squeezing, because after that they are rapidly lost. The product thus obtained is used for coloring food products, but also for the production of non-toxic inks and ecological paints.
In Central Europe, chokeberry is used in the pharmaceutical industry and herbal medicine as a medicinal plant. Concentrated juice is used as protection against cardiovascular disorders, because it reduces blood pressure. Fresh juice, either from fruits or leaves, is used for external use in case of burns and bleeding, and as a prophylaxis during anticoagulant therapy. In Poland, Geriasol®, a product based on chokeberry juice intended for the elderly population, and Aroniovit®, chokeberry juice with the addition of vitamin C are sold. In Russia, a preparation with vitamins P and C is produced, the first of which is obtained from chokeberry pomace. This product contains from 17.000 to 18.000 mg / 100 g of vitamin P, and is recommended for the therapy of venous capillaries. Finally, decoctions are produced with a mixture of chokeberry and other dried fruits, such as white hawthorn and wild rose.