The Styrian oil pumpkin (''

Cucurbita pepo ''Cucurbita pepo'' is a cultivated plant of the genus ''Cucurbita''. It yields varieties of winter squash and pumpkin, but the most widespread varieties belong to the subspecies ''Cucurbita pepo'' subsp. ''pepo'', called summer squash. It has b ...

'' var. ''styriaca''), also known as the Styrian pumpkin, is a variety of the common

pumpkin A pumpkin is a cultivar, cultivated winter squash in the genus ''Cucurbita''. The term is most commonly applied to round, orange-colored squash varieties, but does not possess a scientific definition. It may be used in reference to many dif ...

(''Cucurbita pepo pepo'') which is cultivated to produce pumpkin seed oil. The young fruits are dark green, turning yellow-orange upon ripening. They have a

mutation In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, ...

resulting in the loss of the lignified seed shell. Approximately 2.5 kg of seed, the equivalent or 30–40 pumpkins, produce 1 liter of pumpkin seed oil. On average, a ripe oil pumpkin weighs between 8 and 10 kilograms.

History

The Styrian oil pumpkin is of relatively recent origin. Its crucial mutation, resulting in distinctive dark green seeds, was first recorded between 1870 and 1880. This accidental natural mutation is the result of an alteration in a single recessive gene. The soft seed coat made efficient oil extraction possible and enabled the production of the renowned Styrian pumpkin seed oil, a regional specialty in

southeastern Europe Southeast Europe or Southeastern Europe is a geographical sub-region of Europe, consisting primarily of the region of the Balkans, as well as adjacent regions and Archipelago, archipelagos. There are overlapping and conflicting definitions of t ...

. The oil's history is closely tied to the economic and cultural dynamics of the area. Today,

adulteration An adulterant is a substance secretly added to another that may compromise the safety or effectiveness. Typical substances that are adulterated include food, cosmetics, pharmaceuticals or fuels. Definition Adulteration is the practice of secre ...

of Styrian pumpkin seed oil is considered professional fraud. Cheaper edible oils, such as sunflower oil,

rapeseed oil Close-up of canola blooms Canola flower Rapeseed oil is one of the oldest known vegetable oils. There are both edible and industrial forms produced from rapeseed, the seed of several cultivars of the plant family Brassicaceae. Historica ...

, or

soybean oil Soybean oil (British English: soyabean oil) is a vegetable oil extracted from soybean (''Glycine max'') legumes. It is one of the most widely consumed cooking oils and the second most consumed vegetable oil. As a drying oil, processed soybean oil ...

, are common adulterants.

Distribution

It is traditionally cultivated industrially in parts of the former

Austro-Hungarian Empire Austria-Hungary, also referred to as the Austro-Hungarian Empire, the Dual Monarchy or the Habsburg Monarchy, was a multi-national constitutional monarchy in Central Europe between 1867 and 1918. A military and diplomatic alliance, it consist ...

, in present-day south-eastern

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

(

Styria Styria ( ; ; ; ) is an Austrian Federal states of Austria, state in the southeast of the country. With an area of approximately , Styria is Austria's second largest state, after Lower Austria. It is bordered to the south by Slovenia, and cloc ...

), north-eastern

Slovenia Slovenia, officially the Republic of Slovenia, is a country in Central Europe. It borders Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the south and southeast, and a short (46.6 km) coastline within the Adriati ...

(Styria,

Prekmurje Prekmurje (; Prekmurje Slovene: ''Prèkmürsko'' or ''Prèkmüre''; ) is a geographically, linguistically, culturally, and ethnically defined region of Slovenia, settled by Slovenes and a Hungarians in Slovenia, Hungarian minority, lying betwee ...

), central

Transylvania Transylvania ( or ; ; or ; Transylvanian Saxon dialect, Transylvanian Saxon: ''Siweberjen'') is a List of historical regions of Central Europe, historical and cultural region in Central Europe, encompassing central Romania. To the east and ...

and the

Orăștie Orăștie (; , , , '' Transylvanian Saxon'': Brooss) is a small town and municipality in Hunedoara County, south-western Transylvania, central Romania. History 7th–9th century – On the site of an old swamp was a human settlement, ...

- Cugir region of

Romania Romania is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern and Southeast Europe. It borders Ukraine to the north and east, Hungary to the west, Serbia to the southwest, Bulgaria to the south, Moldova to ...

, north-eastern

Croatia Croatia, officially the Republic of Croatia, is a country in Central Europe, Central and Southeast Europe, on the coast of the Adriatic Sea. It borders Slovenia to the northwest, Hungary to the northeast, Serbia to the east, Bosnia and Herze ...

( Međimurje),

Vojvodina Vojvodina ( ; sr-Cyrl, Војводина, ), officially the Autonomous Province of Vojvodina, is an Autonomous administrative division, autonomous province that occupies the northernmost part of Serbia, located in Central Europe. It lies withi ...

and neighbouring parts of

Hungary Hungary is a landlocked country in Central Europe. Spanning much of the Pannonian Basin, Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croatia and ...

. In these countries, the use of pumpkin seed oil in the diet is traditional. The Styrian oil pumpkin is also widespread in the far eastern part of Europe (

Ukraine Ukraine is a country in Eastern Europe. It is the List of European countries by area, second-largest country in Europe after Russia, which Russia–Ukraine border, borders it to the east and northeast. Ukraine also borders Belarus to the nor ...

) and in

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

, North America,

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

and

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

Nutritional value

The oil's fatty acid profile, with

polyunsaturated fatty acids In biochemistry and nutrition, a polyunsaturated fat is a fat that contains a polyunsaturated fatty acid (abbreviated PUFA), which is a subclass of fatty acid characterized by a backbone with two or more carbon–carbon double bonds. Some polyunsa ...

constituting approximately 45.6 ± 5%rel, surpasses monounsaturated (35.9 ± 10%rel) and

saturated fatty acids In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, f ...

(18.5 ± 20%rel).

Linoleic acid Linoleic acid (LA) is an organic compound with the formula . Both alkene groups () are ''cis''. It is a fatty acid sometimes denoted 18:2 (n−6) or 18:2 ''cis''-9,12. A linoleate is a salt or ester of this acid. Linoleic acid is a polyunsat ...

oleic acid Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish due to the presence of impurities. In chemical terms, oleic acid is cl ...

palmitic acid Palmitic acid (hexadecanoic acid in IUPAC nomenclature) is a fatty acid with a 16-carbon chain. It is the most common saturated fatty acid found in animals, plants and microorganisms.Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra. The ...

, and

stearic acid Stearic acid ( , ) is a saturated fatty acid with an 18-carbon chain. The IUPAC name is octadecanoic acid. It is a soft waxy solid with the formula . The triglyceride derived from three molecules of stearic acid is called stearin. Stearic acid ...

dominate, collectively accounting for nearly 98% of the fatty acids present. Minimal traces of other fatty acids are also present. High-quality pumpkin seed oil has γ-tocopherol with concentrations reaching 800 mg/kg. This oil's γ-tocopherol levels are higher than its α-tocopherol levels. The oil also contains

vitamin A Vitamin A is a fat-soluble vitamin that is an essential nutrient. The term "vitamin A" encompasses a group of chemically related organic compounds that includes retinol, retinyl esters, and several provitamin (precursor) carotenoids, most not ...

carotenoid Carotenoids () are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, archaea, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, cana ...

s such as

lutein Lutein (;"Lutein"

β-carotene, and several

vitamin B B vitamins are a class of water-soluble vitamins that play important roles in cell metabolism and synthesis of red blood cells. They are a chemically diverse class of compounds. Dietary supplements containing all eight are referred to as a vita ...

compounds. Styrian pumpkin seed oil exhibits elevated levels of

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

, and

phosphorus Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...

, with

selenium Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...

being detected. The oil contains

phytosterol Phytosterols are phytosteroids, similar to cholesterol, that serve as structural components of biological membranes of plants. They encompass plant sterols and stanol ester, stanols. More than 250 sterols and related compounds have been identified ...

s, approximately 2–2.5 times more concentrated than in the seeds, with D7-sterols being predominant. Styrian pumpkin seed oil owes its dark green color and distinct aroma to compounds like protochlorophyll, protopheophytin, and carotenoids. The aroma, characterized by a nutty roast, results from a roasting process involving high temperatures of extended duration. The oil also exhibits

antioxidant Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants ...

properties attributed to its phenolic compounds, which constitute up to 40% of the total antioxidant capacity. Although Styrian pumpkin seed oil contains significant amounts of antioxidants, the green pigments in the oil act make it light sensitive and shorten its

shelf life Shelf life is the length of time that a commodity may be stored without becoming unfit for use, consumption, or sale. In other words, it might refer to whether a commodity should no longer be on a pantry shelf (unfit for use), or no longer on a s ...

. They are efficient sensitizers for light-induced fatty acid

oxidation Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...

and, along with a high content of polyunsaturated fatty acids, make it susceptible to

rancidity Rancidification is the process of complete or incomplete autoxidation or hydrolysis of fats and oils when exposed to air, light, moisture, or bacterial action, producing short-chain aldehydes, ketones and free fatty acids. When these processes ...

Cultivation, production and storage

Sowing

Styrian oil pumpkins are sown at appropriate soil temperature between mid to late April. It is sown into a seedbed of sandy, well-drained soil at a depth of 3–4 cm with a row distance of 80 cm. Heavy wet clay soils are not appropriate. A planting density of 17,000 seeds per

hectare The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), that is, square metres (), and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. ...

is appropriate. For

organic farming Organic farming, also known as organic agriculture or ecological farming or biological farming,Labelling, article 30 o''Regulation (EU) 2018/848 of the European Parliament and of the Council of 30 May 2024 on organic production and labelling of ...

20,000 seeds per hectare should be sown for better competition against weeds.

Fertilisation

The styrian oil pumpkin requires 150 kg/ha of

Nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

, 13.1 kg/ha of Phosphorus, 124.5 kg/ha of Potassium and 10 kg/ha of Magnesium.

Crop protection

cultivator A cultivator (also known as a rotavator) is a piece of agricultural machinery, agricultural equipment used for secondary tillage. One sense of the name refers to frames with ''teeth'' (also called ''shanks'') that pierce the soil as they ar ...

or appropriate chemicals can be used to combat weeds. There are no known

fungicide Fungicides are pesticides used to kill parasitic fungi or their spores. Fungi can cause serious damage in agriculture, resulting in losses of yield and quality. Fungicides are used both in agriculture and to fight fungal infections in animals, ...

s with a significant effect in this culture.

Insecticide Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, i ...

s can have be significantly effective against

aphid Aphids are small sap-sucking insects in the Taxonomic rank, family Aphididae. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white Eriosomatinae, woolly ...

s. The lack of a lignified seed shell makes it susceptible to soil-borne fungal diseases, increasing the risk of poor seed germination, especially in wet years. The pumpkin is also susceptible to fruit rot.

Harvest

The crop is harvested around September and October. It is ready when plant material is dead and the kernels are easily torn out of the fruit flesh. The pumpkins are harvested by first placing the plants into a swath. Then the pumpkins are picked and broken up. When opened, a harvester in the field removes the seeds using

centrifugal force Centrifugal force is a fictitious force in Newtonian mechanics (also called an "inertial" or "pseudo" force) that appears to act on all objects when viewed in a rotating frame of reference. It appears to be directed radially away from the axi ...

. The fruit flesh is discharged on the spot. Then the kernels can be transferred from the field.

Areas of cultivation and production

The climatic conditions in the areas of mid-Eastern Europe are suitable and, in particular, the average annual rainfall is often less than 800mm. World production of oil pumpkins is estimated at a total area of 600,000 hectares and a total yield of 200,000 tonnes of pumpkin seeds. Of this, approximately 120,000 tonnes of pumpkin seeds are produced in China. Huge quantities of these seeds also end up on the European market. World consumption of pumpkin seeds is as follows: * 80% (160,000 tonnes) is used in the baking industry, * 10% (20,000 tonnes) is processed into oil, * 10% (20,000 tonnes) is used for other uses.

References

{{Reflist Cucurbita Vegetable oils Economy of Styria Agriculture in Slovenia