Sunflower, Helianthus annuus

The sunflower owes its Latin name ‘Helianthus’ to the way it grows and its characteristic movement. ‘Helios’ for sun and ‘Anthos’ for plant point to the special characteristic of sunflowers. The plant can be observed following the path of the sun throughout the day and always ‘looking’ in its direction.

Hairy stems and heart-shaped leaves

The common sunflower belongs to the composite family. It is characterised by growth heights of one to two metres. The plant is vigorous, has a hairy stem and large heart-shaped leaves. The flower heads are between 20 and 40 cm wide and bloom in various shades of yellow and red. After fertilisation, sunflower seeds are produced in the middle of the flower heads, from which sunflower seeds can be obtained. The sunflower has a strong, long taproot as a support, which is surrounded by a dense root network for water absorption. During the growth phase, which lasts around 150 days, the plants have a high demand for water and nutrients.

The sunflower’s journey around the world

The wild plant is native to southern North America and Central America. The first domestication as a source of edible seeds probably took place around 3,000 to 5,000 years ago in the Midwest of what is now the USA. Descendants of these early domestications were introduced to Europe in the early 16th century and eventually reached Russia, where the forerunners of modern oilseed varieties were developed and cultivated on an industrial scale. These Russian oilseed varieties were reintroduced to North America in the mid-20th century, boosting commercial sunflower production in the Americas and ushering in the modern era of sunflower breeding. Today, the sunflower is an important oil crop and is grown in many countries around the world. Russia, Ukraine and Argentina are the countries with the largest areas of sunflower cultivation.

Cell protection through vitamin E

Sunflower seeds have been eaten raw or roasted in different regions of the world for thousands of years. Sunflower seeds contain around 20 % protein and various minerals, as well as vitamins and large amounts of unsaturated fatty acids. Sunflower oil, on the other hand, is still a fairly new phenomenon. Oil has only been pressed from the seeds since the 19th century. In contrast to rapeseed or olive oil, the oil does not have such a favorable fatty acid composition. However, it is rich in vitamin E, which is important for protecting our cells. The residue from the oil pressing process is called press cake and is used as animal feed. Sunflower seeds are also frequently found in bird feed. The large sunflowers are also popular as an ornamental plant in gardens or vases.

Effects of the Russian-Ukrainian war

The war in Ukraine, which has been raging since February 2022, has had a far-reaching impact on the global food supply. Before the war, Ukraine and Russia were the main exporters of sunflower seeds, oil and press cake, which led to shortages when the war began. In other countries, cultivation increased slightly, but as Ukrainian farmers also produce seeds for sunflower cultivation, the war has had an impact on the cultivation of sunflowers in other countries as well as significantly reducing exports.

Changed oleic acid content through breeding

For some years now, so-called high-oleic oils have been available on the market, which are pressed from sunflowers, among other things, and whose oil composition differs from that of previous sunflower oils. Cultivation has increased the oleic acid content from 40% to over 90%. Most high-oleic oils (HO oils) contain between 75% and 90% oleic acid and only small amounts of linoleic acid. HO oils with a high oleic acid content are of interest to industry, as the oil is particularly stable and in some cases superior to mineral oils in terms of its properties. But HO oil is also of interest in the world of nutrition. Oleic acids are monounsaturated fatty acids and are therefore heat-stable. HO oils are therefore an alternative to oils with unhealthy trans fatty acids, which are used for deep-frying or in baked goods.

Sources

Rieseberg, L.H., Seiler, G.J. Molecular Evidence and the Origin and Development of the Domesticated Sunflower(Helianthus annum, Asteraceae). Econ Bot 44 (Suppl 3), 79-91 (1990). Link.
Park & Burk (2020): Phylogeography and the Evolutionary History of Sunflower (Helianthus annuus L.): Wild Diversity and the Dynamics of Domestication. Link.
Medienwerkstatt Wissensarten: Sunflower. Link.
Barrio-Conde, M.; Zanella, M.A.; Aguiar-Perez, J.M.; Ruiz-Gonzalez, R.; Gomez-Gil, J. A Deep Learning Image System for Classifying High Oleic Sunflower Seed Varieties. Sensors 2023, 23, 2471. link.