Specification & Spread
Blueberry fruits — fructus myrtilli
Blueberry shoots — cormi myrtilli
Blueberry — Vaccinium myrtillus L.
Ericaceous family — Ericaceae (Vaccinioideae)
Other names: bilberry, blueberry, inkberry, hurtleberry, heathberry.
It is a shrub 15-40 (50) cm tall.
The stem is rounded, erect, branched, brown and green. The branches are sharply ribbed.
The leaves are collapse, alternate, short-petiolate, thin, ovate or elliptical. It has a finely serrated margin and on both sides it is slightly pubescent.
The flowers are small, solitary and androgynous. It is on short pedicels and occurs in the leaf axils.
The corolla is spherical, greenish-pink, drooping with 4-5 curved teeth. The ovary is inferior and 4-5-locular.
The fruit is black or bluish spherical berry with small seeds.
It blooms in May - June, the fruits ripen in July - August.
Spreading. This plant grows in Belarus, int the European part of Russia, in the Caucasus, in Western and Eastern Siberia.
Habitat. It grows in coniferous green moss, rarely in mixed and small-leaved forests, also among shrubs, as well as in swampy coniferous forests. Very often blueberry forms large thickets which is used for harvesting.
- sugar (fructose, lactose),
- P-active substances (catechins and anthocyanins),
- pectic substances,
- condensed tannins (5-7%),
- organic acids.
Blueberry pulp is red-purple in colour which is determined by a mixture of anthocyanins - glycosides of delphinidin and malvidin.
Blueberry shoots and leaves contain:
- up to 20% tannins,
- as well as hydroquinone,
- up to 1% of arbutin,
- flavonoids (quercetin, rhamnoside quercetin),
- up to 250 mg% of ascorbic acid.
Blueberry has biologically important glycosides - neomirtillin (2%), the aglycone of which is a vitamin-like substance - inositol
and mirtillin (1%), that belong to the anthocyanin group.
Harvesting and storage of raw materials
Harvesting. The fruits of blueberry are harvested only when it ripens (first half of August) in dry weather and in a small container (buckets, baskets). The harvested fruits are cleared of impurities (moss, twigs, needles, unripe berries). It is forbidden to wash blueberry and transfer it from one container to another.
The shoots are harvested from the end of flowering until the end of fruiting (June-July), by cutting off leafy, non-woody parts with flowers and fruits which is up to 15 cm long.
Security measures. While planning harvesting, it is necessary take into account the frequency of blueberry fruiting. Besides, it is important to alternate the harvesting areas. It is not advisable for the shoot harvesting to use high-yielding blueberry thickets suitable for the fruit gathering. The shoot gathering should be concentrated in populations with consistently low fruiting.
Drying. Before the final drying blueberry fruits are dried for 2-3 hours at a temperature of 35-40 °C. Then it is dried at a temperature of 55-60 °C in a special dryer. In addition, it could be dried in Russian ovens, in sunny weather and open air by spreading it on fabric or paper with a layer of 1-2 cm. It also could be dried in attics with good ventilation. When the berries don’t get the hands dirty and stick together in lumps, the process of drying is completed.
Blueberry shoots are dried in open air or heat dryers with good ventilation.
Storage. Blueberry fruits and shoots are stored in a dry and well-ventilated area.
External signs of raw materials
The fruits are berries with a diameter of 3-6 mm, shapeless, strongly shriveled and spherical in the soaked form. At the top of the fruit, the rest of the catyx is visible in the form of a small annular rim surrounding the swollen disk with the remainder of the stab in the center or with a small indentation after it falls off.
There are numerous (up to 30 pieces) and ovoid seeds (Fig. 9.25, B) in the fruit pulp. Very often the base of the fruit has a short stalk.
The fruits are black with a reddish tinge, matte or slightly shiny; the pulp is red-purple; the seeds are red-brown.
The smell is weak. The taste is sweet-sour and slightly astringent.
The shoots are a mixture of whole or broken up tops of shoots, separate stems up to 15 cm long, leaves, less often buds, flowers and fruits. The taste is bitter and astringent.
Impurities. There are possible impurities to the fruits of blueberry presented in the table and in figure 9.25.
Distinctive features of blueberry and possible impurities
Blueberry — Vaccinium myrtillus L. is a spherical, almost black fruit, with the remnant of the calyx in the form of an annular rim at the apex, in the center there are a dimple. The pulp is reddish-purple and strongly colouring. The seeds are oblong, small and numerous. The taste is sour-sweet and astringent.
Bilberry — Vaccinium uliginosum L. is oval, larger than blueberry fruits, dark blue fruit with a waxy coating, a remnant of the calyx in the form of an annular rim and dimple. The pulp is green. The seeds are oblong, small and numerous. The taste is sweet and slightly astringent.
Black currant — Ribes nigrum L. is a spherical, black fruit, with a filmy cone-shaped perianth remnant at the apex. The surface is seated with yellow glands visible in a magnifying glass. The seeds are smooth, numerous, larger than those of blueberry. The taste is sour and slightly tart; the smell is fragrant.
Bird cherry — Padus avium Mill. is a spherical, black fruit, with a white bloom from sugar and a round white scar from the stem. The stone is single and rounded shape. The taste is sour-sweet and strongly astringent.
Inedible fruits (unacceptable impurities) European elder — Sambucus nigra L. is spherical, small, black fruit, with the remnant of the calyx in the form of a five-toothed rim at the apex, in the center there is a dimple. The pulp is dark red. The stones are (3) oblong-ovate and transversely wrinkled. The taste is sour-sweet.
Persian berry — Frangula alnus Mill. is a spherical, black and shiny fruit. The stones (2) are flat with a cartilaginous coracoid process. It causes vomiting.
European buckthorn - Rhamnus cathartica L. is a spherical, black and shiny fruit. The pulp is brown-green. The stones (3-4) are triangular, with 2 flat and 1 convex sides. The taste is sweet and bitter; the smell is unpleasant.
Aiten — Juniperus communis L. is smooth, spherical, black or purple fruit, there is a three-beam seam at the apex. The pulp is yellowish-brown. The seeds (3) are smooth, light yellow, angular in shape. The taste is sweet and spicy; the smell is fragrant.
Properties and application
There are some properties that blueberry fruits possess:
- anti-rotten and
- antimicrobial properties.
While interacting with the proteins of the mucous membranes in the gastrointestinal tract, tannins of blueberry fruit condense the surface layer of the mucous membrane. The formed membrane liner protects the cells of tissues from various stimuli, that reduce pain, inflammation and secretion, slow intestinal motility and absorption.
The pectic substances of blueberry fruit adsorb intestinal toxins and the composition of the intestinal flora is improved under the action of organic acids.
Blueberry anthocyanic glycosides and carotenoids contribute to the regeneration of the photosensitive retina pigment - rhodopsin. Thus, the sensitivity of the retina to different levels of light is increased and visual acuity is enhanced in low light. Moreover, all this improve the retinal trophic and suppress the pathological mechanisms of cataract formation.
There are reports which inform that blueberry anthocyanins reduce the aggregation capacity of erythrocytes in vitro.
The biologically active substances of blueberry leaves have been studied in many countries.
Blueberry leaf preparations have:
- anti-inflammatory and
- anti-rotten action.
The preparations from blueberry leaves lower blood sugar.
Application of blueberry
The decoction from blueberry fruits is used as an astringent in:
- acute and chronic disorders of the gastrointestinal tract and diarrhea, dyspepsia associated with enhanced fermentation and putrefactive processes, colitis, enterocolitis, dysentery.
Topically, blueberry fruit decoction is used as an astringent and antiseptic in stomatitis and gingivitis. Blueberry is used as a dietary and therapeutic agent in:
- mild diabetes.