Goji Berries

Botanical Profile

Note on species delimitation: Sweet orange (Citrus sinensis) and bitter orange (Citrus × aurantium) should be considered separately in botanical and phytochemical statements.

Goji berries are derived predominantly from Lycium barbarum, a northern and central Chinese shrub of the Solanaceae. The red fruits combine East Asian cultural history, modern food raw-material science and a characteristic profile of polysaccharides, carotenoids and phenolic compounds.

Lycium barbarum L. belongs to the Solanaceae. Kew accepts the species and describes northern and central China as its native range. Today the plant is introduced or naturalised in numerous regions. Its fruits are commonly known as goji berries or wolfberries; botanically, however, it is important to distinguish Lycium barbarum from related species such as Lycium chinense.

Botanically, it is a deciduous, loosely branched shrub with often arching shoots. The leaves are narrowly elliptical to lanceolate. The flowers are usually violet to purple and five-petalled, typical of many Solanaceae. They develop into elongated to ovoid red berries containing numerous small seeds.

Lycium species often grow in dry open landscapes, on embankments, roadsides, in scrub and disturbed sites. In cultivation, goji shrubs are grown particularly in drier regions of northern and western China. The fruits are generally dried, as dried goji berries are the principal internationally traded raw material. Ethnobotanically, Lycium barbarum is closely linked to Chinese plant and food culture.

Phytochemistry

The phytochemistry of Lycium barbarum fruits is characterised by several groups of substances. Polysaccharide fractions, frequently described as Lycium barbarum polysaccharides, are particularly well known. These are not a single compound but complex heterogeneous carbohydrate fractions.

A second important group consists of carotenoids. The red to orange colour of the fruits is substantially determined by zeaxanthin derivatives and other carotenoids. Zeaxanthin dipalmitate in particular is regularly cited in the literature as a characteristic constituent of goji fruits.

Flavonoids, phenolic acids, organic acids, amino acids, sugars, minerals and vitamins complement the profile. Exact composition depends on species, variety, origin, ripeness, drying and storage. Modern analytics uses HPLC, LC-MS, polysaccharide analysis and spectrophotometric methods.

Traditional Uses

Lycium barbarum has a long history in Chinese food culture and traditional plant knowledge. The dried red fruits have been known in China for centuries and are used in soups, teas, rice dishes, desserts and various traditional preparations.

Regional cultivation areas, particularly in northern and western China, developed their own quality concepts. Origin, colour, size, drying and sensory properties of the fruits were important to trade and use.

In Europe, goji berries became widely known only comparatively recently. While Lycium species had long occurred as ornamental or hedge plants, the international goji food raw material developed particularly in the late twentieth and early twenty-first centuries. Ethnobotanically, goji is an example of a regional traditional fruit becoming an international raw material through global trade.

Current Research

Modern research on Lycium barbarum addresses phytochemistry, food quality, polysaccharide fractions, carotenoids, origin analytics and cultivation. One focus is on Lycium barbarum polysaccharides, whose composition, molecular weights and structural characteristics are investigated.

Carotenoid research is a second important area. Zeaxanthin dipalmitate and related carotenoids are regarded as markers of fruit quality and origin. HPLC and LC-MS methods permit quantification of individual pigments and assessment of processing effects.

Authenticity is also relevant. Commercial material may include different Lycium species, varieties or origins. DNA barcoding, metabolomic fingerprints and chromatographic profiles are used to assess identity and quality.

Sources

• Plants of the World Online. Kew Science. Royal Botanic Gardens, Kew.
• Flora of China.
• PubMed-indexed specialist literature on Lycium barbarum.
• Specialist literature on Lycium barbarum polysaccharides.
• Specialist literature on zeaxanthin derivatives and carotenoids in goji fruits.