The sea-buckthorn , is deciduous shrubs in the Elaeagnaceae family .

Taxonomy

In ancient times, leaves and young branches of sea-buckthorn were supposedly fed as a remedy to horses to support weight gain and appearance of the coat, thus leading to the name of the genus, Hippophae derived from hippo (horse), and  phaos (shining).

Distribution

Seven species are recognized that two of them probably of hybrid origin that they are  native over a wide area of  Europe and Asia.

Hippophae rhamnoides, the common sea buckthorn, in central Asia, it is more widespread in dry semi desert sites where other plants cannot survive the dry conditions. In central Europe and Asia, it is also occurs as a subalpine shrub above tree line in mountains, and other sunny areas such as river banks. They are tolerant of salt in the air and soil, but demand full sunlight for good growth and do not tolerate shady conditions near larger trees. They typically grow in dry, sandy areas.

Sea-buckthorn is where the plant used for soil, water and wildlife conservation, anti-desertification purposes and for consumer products.

Sea buckthorn hardiness zones are approximately 3 through 7.

Description

The shrubs in central Asia reach 0.5–6 meters tall, rarely up to 10 meters. The leaf arrangement can be alternate, or opposite.

Common sea buckthorn has branches that are dense,  stiff, and very thorny.

The leaves are a distinct pale silvery-green, lanceolate, 3–8 centimeters long and less than 7 millimeters broad. It is dioecious, with separate male and female plants. The male produces brownish flowers which produce wind-distributed pollen. The female plants produce orange berries 6–9 millimeters in diameter, soft, juicy and rich in oils. The roots distribute rapidly and extensively, providing a non-leguminous nitrogen fixation role in surrounding soils.

Hippophae salicifolia (willow-leaved sea buckthorn) is restricted to the Himalayas, to the south of the common sea buckthorn, growing at high altitudes in dry valleys; it differs from H. rhamnoides in having broader (to 10 millimeters) and greener (less silvery) leaves, and yellow berries. A wild variant occurs in the same area, but at even higher altitudes in the alpine zone. It is a low shrub not growing taller than 1 meter with small leaves 1–3 centimeters long.

Species

• Hippophae goniocarpa
• Hippophae gyantsensis
• Hippophae litangensis
• Hippophae neurocarpa
• Hippophae rhamnoides– common sea buckthorn
• Hippophae salicifolia
• Hippophae tibetana

A study of nuclear ribosomal internal transcribed spacer sequence data showed that the genus can be divided into three monophyletic clades:

• tibetana
• rhamnoides with the exception of  H. rhamnoides ssp.  Gyantsensis  (=H. gyantsensis) 
• remaining species

A study using chloroplast sequences and morphology, however, recovered only two clades:

• tibetana, H. gyantsensis, H. salicifolia, H. neurocarpa
• rhamnoides

Natural history

The fruit is an important winter food resource for some birds, notably fieldfares.

Leaves are eaten by the larva of the coastal race of the ash pug moth and by larvae of other Lepidoptera including brown-tail, dun-bar, emperor moth, mottled umber and Coleophora elaeagnisella.

Uses

Fruit harvesting

Because of the dense thorn arrangement among the berries on each branch harvesting  is difficult . A common harvesting technique is to remove an entire branch, though this is destructive to the shrub and reduces future harvests. A branch that removed in this way is then frozen, allowing the berries to be easily shaken off.

The worker then crushes the berries to remove up to 95% of the leaves and other debris. This causes the berries to melt slightly from the surface as the work takes place at ambient temperature (about 20 °C). Berries or the crushed pulp are later frozen for storage.

The most effective way to harvest berries and not damage branches is by using a berry-shaker. Mechanical harvesting leaves up to 50% in the field and the berries can be harvested only once in two years. They only get about 25% of the yield that could be harvested with this relatively new machinery.

Products

Sea buckthorn berries are edible and nutritious, though astringent, sour and oily, unpleasant to eat raw, unless ‘bletted‘ and/or mixed as a drink with sweeter substances such as apple or grape juice. Mechanism behind this change is transformation of malic acid into lactic acid in microbial metabolism.

When the berries are pressed, the resulting sea buckthorn juice separates into three layers: on top is a thick, orange cream; in the middle, a layer containing sea buckthorn’s characteristic high content of saturated and polyunsaturated fats; and the bottom layer is sediment and juice. Containing fat sources applicable for cosmetic purposes, the upper two layers can be processed for skin creams and liniments, whereas the bottom layer can be used for edible products like syrup.

Besides juice, sea buckthorn fruit can be used to make pies, jams, lotions, teas, fruit wines and liquors. The juice or pulp has other potential applications in foods, beverages or cosmetics products. Fruit drinks were among the earliest sea buckthorn products developed in China. Sea buckthorn-based juice is popular in Germany and Scandinavian countries. It provides a nutritious beverage, rich in vitamin C and carotenoids.

For its troops confronting extremely low temperatures , India’s Defence Research Development Organizationestablished a factory in Leh to manufacture a multi-vitamin herbal beverage based on sea buckthorn juice.

The seed and pulp oils have nutritional properties that vary under different processing methods. Sea buckthorn oils are used as a source for ingredients in several commercially available cosmetic products and nutritional supplements.

Landscape uses

Sea buckthorn is a popular garden and landscaping shrub with an aggressive basal shoot system used for barrier hedges and windbreaks, and to stabilize riverbanks and steep slopes. They have value in northern climates for their landscape qualities, as the colorful berry clusters are retained through winter. Branches may be used by florists for designing ornaments.

In northwestern China, sea buckthorn shrubs have been planted on the bottoms of dry riverbeds to increase water retention of the soil and thus decrease sediment loss. Because of increased moisture conservation of the soil and nitrogen-fixing capabilities of sea buckthorn, vegetation levels have increased in areas where sea buckthorn have been planted. Sea buckthorn was once distributed free of charge to Canadian prairie farmers by PFRA to be used in shelterbelts.

Chemical Composition

Fruit

Sea buckthorn fruit consists of sugars, sugar alcohols, fruit acids, vitamins (C, E and K), phenolic compounds, carotenoids, fiber, amino acids, minerals and plant sterols. The fruit contains many of these in high amounts, and is thus considered highly nutritious. Species belonging to genus Hippophae accumulate oil both in soft parts and in seed of the fruit. Oil content in soft parts is 1.5–3 % while in seed this is 11% of the fresh weight. For the compositions of sea buckthorn oils, see article: sea buckthorn oil.

Major sugars in sea buckthorn fruits are fructose and glucose. Typical sourness of the fruits is due to high content of malic acid while astringency is related toquinic acid. Major sugar alcohol in fruit is L-quebrachitol .

The fruit of the plant has a high vitamin C content – in a range of 114 to 1550 mg per 100 grams with an average content, placing sea buckthorn fruit among the most enriched plant sources of vitamin C. Additionally, fruits have high concentrations of carotenoids, vitamin E and vitamin K. The main carotenoids are beta-carotene,zeaxanthin and lycopene while alpha-tocopherol is the major vitamin E compound.

The most prevalent dietary minerals in sea buckthorn fruits  are potassium, manganese and copper.

The fruit is also rich in plant sterols, β-sitosterol being the major sterol compound as it constitutes 57–83 % of total sterols.

Potential Health effect

Traditional medicine

Different parts of sea buckthorn have been used as traditional therapies for diseases. Bark and leaves have been used for treating diarrhea and dermatological disorders. Berry oil, either taken orally or applied topically, is believed to be a skin softener.

Research

Impact of sea buckthorn berries on the risk of cardiovascular disease is currently under preliminary research, involving studies with fresh and dried berries, extracts and oil from whole berry, pulp or seeds.