The oil is an important export commodity of Austria and Slovenia. It is made by pressing roasted, hulledpumpkin seeds (pepitas), from a local variety of pumpkin, the "Styrian oil pumpkin" (Cucurbita pepo subsp. pepo var. 'styriaca', also known as var. oleifera). It has been produced and used in Styria's southern parts at least since the 18th century. The earliest confirmed record of oil pumpkin seeds in Styria (from the estate of a farmer in Gleinstätten) dates to February 18, 1697.
The viscous oil is light to very dark green to dark red in colour depending on the thickness of the observed sample. The oil appears green in thin layer and red in thick layer. Such optical phenomenon is called dichromatism. Pumpkin oil is one of the substances with strongest dichromatism. Its Kreft's dichromaticity index is -44. Used together with yoghurt, the colour turns to bright green and is sometimes referred to as "green-gold".
Pumpkin seed oil has an intense nutty taste and is rich in polyunsaturated fatty acids. Browned oil has a bitter taste. Pumpkin seed oil serves as a salad dressing when combined with honey or olive oil. The typical Styrian dressing consists of pumpkin seed oil and cider vinegar. The oil is also used for desserts, giving ordinary vanilla ice cream a nutty taste. It is considered a real delicacy in Austria and Slovenia, and few drops are added to pumpkin soup and other local dishes. Using it as a cooking oil, however, destroys its essential fatty acids.
Other types of pumpkin seed oil are also marketed worldwide. International producers use white seeds with shells and this produces a cheaper white oil. New producers of seeds are located in China and India.
An analysis of the oil extracted from the seeds of each of twelve cultivars of C. maxima yielded the following ranges for the percentage of several fatty acids:
The sum of myristic and palmitic acid (cholesterogenic saturated fatty acids) content ranged from 12.8 to 18.7%. The total unsaturated acid content ranged from 73.1 to 80.5%. The very long chain fatty acid (> 18 carbon atoms) content ranged from 0.44 to 1.37%.
^Košťálová, Zuzana; Hromádková, Zdenka; Ebringerová, Anna (August 2009). "Chemical Evaluation of Seeded Fruit Biomass of Oil Pumpkin (Cucurbita pepo L. var. Styriaca)". Chemical Papers (Springer Versita for Institute of Chemistry) 63 (4): 406–413. doi:10.2478/s11696-009-0035-5.
^Kreft, Samo; Kreft, Marko (2009). "Quantification of Dichromatism: A Characteristic of Color in Transparent Materials". Journal of the Optical Society of America (Optical Society of America) 26 (7): 1576–1581. doi:10.1364/JOSAA.26.001576. PMID19568292.
^Ejike, C. E.; Ezeanyika, L. U. (2011). "Inhibition of the Experimental Induction of Benign Prostatic Hyperplasia: A Possible Role for Fluted Pumpkin (Telfairia occidentalis Hook f.) Seeds.". Urologia Internationalis87 (2): 218–224. doi:10.1159/000327018. ISSN1423-0399. PMID21709398.
^Gossell-Williams, M.; Davis, A.; O'Connor, N. (2006). "Inhibition of Testosterone-induced Hyperplasia of the Prostate of Sprague-Dawley Rats by Pumpkin Seed Oil". Journal of Medicinal Food9 (2): 284–286. doi:10.1089/jmf.2006.9.284. ISSN1096-620X. PMID16822218.
^Stevenson, D. G.; Eller, F. J.; Wang, L.; Jane, J.; Wang, T.; Inglett, G. E. (2007). "Oil and Tocopherol Content and Composition of Pumpkin Seed Oil in 12 Cultivars". Journal of Agricultural and Food Chemistry55: 4005–4013. doi:10.1021/jf0706979. PMID17439238. Note: The data are found in Table 3 on page 4010
Dreikorn, K.; Berges, R.; Pientka, L.; Jonas, U. (September 2002). "Phytotherapy of Benign Prostatic Hyperplasia. Current Evidence-based Evaluation". Urologe A. (in German) 41 (5): 447–451. ISSN0340-2592. PMID12426861. Only a few randomized clinical trials that meet standard criteria of evidence-based medicine but with relatively short follow-up times and some meta-analyses mainly regarding Serenoa repens and Pygeum africanum as well as more recent studies on pumpkin seeds have shown clinical effects and good tolerability.
Vahlensieck, Jr., W. (18 April 2002). "With alpha blockers, finasteride and nettle root against benign prostatic hyperplasia. Which patients are helped by conservative therapy?". MMW - Fortschritte der Medizin (in German) 144 (16): 33–66. PMID12043098. Summary: Established medications for the treatment of BPH in current use are alpha-blockers, finasteride, and the phytotherapeutic agents pumpkin seed (Cucurbitae semen), nettle root (Urticae radix), the phytosterols contained in Hypoxis rooperi, rye pollen and the fruits of saw palmetto (Sabalis serrulati fructus)
Dreikorn, K. (April 2002). "The role of phytotherapy in treating lower urinary tract symptoms and benign prostatic hyperplasia". World Journal of Urology19 (6): 426–435. doi:10.1007/s00345-002-0247-6. ISSN1433-8726. PMID12022711. Summary: A number of short-term randomised trials and some meta-analyses in the recent literature suggest clinical efficacy and good tolerability for some preparations, mainly extracts from Serenoa repens and also Pygeum africanum, products with high concentrations of beta-sitosterol, and pumpkin seeds.
Bracher, F. (January 1997). "Phytotherapy of Benign Prostatic Hyperplasia". Urologe A. (in German) 36 (1): 10–17. PMID9123676. In this article, the most widely used phytopharmaceutical agents, such as saw palmetto berry extracts, Radix urticae extracts, pumpkin seeds, pollen extracts and different phytosterols, are described. Based on these results, the use of phytopharmaceutical agents for the treatment of mild to moderate symptomatic BPH seems to be well justified.
Carbin, B. E.; Larsson, B.; Lindahl, O. (December 1990). "Treatment of benign prostatic hyperplasia with phytosterols". British Journal of Urology66 (6): 639–641. doi:10.1111/j.1464-410x.1990.tb07199.x. PMID1702340. In a randomised, double-blind study, the preparation Curbicin, obtained from pumpkin seeds and dwarf palm plants (Cucurbita pepo l. and Sabal serrulata), was compared with a placebo in the treatment of symptoms caused by prostatic hyperplasia; 53 patients took part in the study, which was carried out over a 3-month period. Urinary flow, micturition time, residual urine, frequency of micturition and a subjective assessment of the effect of treatment were all significantly improved in the treatment group.