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
A
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