Sunflower oil

Unrefined sunflower oil

Sunflower oil is the non-volatile oil compressed from sunflower (Helianthus annuus) seeds. Sunflower oil is commonly used in food as a frying oil, and in cosmetic formulations as an emollient. The world's largest sunflower oil producers now are Russia, Ukraine and Argentina.[1]

Sunflower oil is a monounsaturated (MUFA)/polyunsaturated (PUFA) mixture of mostly oleic acid (omega-9)-linoleic acid (omega-6) group of oils. The oil content of the seed ranges from 22 to 36% (average, 28%): the kernel contains 45–55% oil. The expressed oil is of light amber color with a mild and pleasant flavor; refined oil is pale yellow. Refining losses are low and the oil has good keeping qualities with light tendency for flavor reversion. The oil contains appreciable quantities of vitamin E, sterols, squalene, and other aliphatic hydrocarbons.

In recent years, there has been an increase in demand for sunflower crops such as sunflower oil. Measures such as the development of hybrid sunflowers to increase oil production have been introduced to meet this demand.[2]

Composition

Sunflower oil is mainly triglycerides (fats), typically derived from the fatty acids linoleic acid (which is doubly unsaturated) and oleic acid

Sunflower oil is mainly a triglyceride; a typical constituent is shown.[3] The British Pharmacopoeia lists the following profile:[4]

Several types of sunflower oils are produced, such as high linoleic, high oleic and mid oleic. Mid-oleic sunflower oil typically has at least 69% oleic acid. High oleic sunflower oil has at least 82% oleic acid. Variation in unsaturated fatty acids profile is strongly influenced by both genetics and climate. In the last decade, high stearic sunflower lines have been developed in Spain to avoid the use of partially hydrogenated vegetable oils in the food industry.[5]

Sunflower oil is high in the essential vitamin E and low in saturated fat. The two most common types of sunflower oil are linoleic and high oleic. Linoleic sunflower oil is a common cooking oil that has high levels of polyunsaturated fat. It is also known for having a clean taste and low levels of trans fat. High oleic sunflower oils are classified as having monounsaturated levels of 80% and above. Newer versions of sunflower oil have been developed as a hybrid containing linoleic acid. They have monounsaturated levels lower than other oleic sunflower oils. The hybrid oil also has lower saturated fat levels than linoleic sunflower oil.[6]

The phosphatides (0.1–0.2%) present in the oil are lecithin (38.5%) and cephalin (61.5%); they occur in combination with protein and carbohydrates.

Sunflower oil also contains lecithin, tocopherols, carotenoids and waxes. Sunflower oil's properties are typical of a vegetable triglyceride oil.

Physical properties

High-oleic sunflower oil

Sunflower oil is liquid at room temperature. The refined oil is clear and slightly amber-colored with a slightly fatty odor.

Smoke point (refined) 232 °C 450 °F[7]
Smoke point (unrefined) 107 °C 225 °F[7]
Density (25 °C) 918.8 kg/m3[8]
Refractive index (25 °C) ≈1.4646[8]
Saponification value 188-194
Iodine value 120-145
Unsaponifiable matter 1.5-2.0%
Viscosity (25 °C), unrefined 0.04914 kg/(M*S)[9]

Nutrition

Sunflower oil, high oleic (70% and over)
Nutritional value per 100 g (3.5 oz)
Energy 3,699 kJ (884 kcal)
0 g
100 g
Saturated 9.748 g
Monounsaturated 83.594 g
Polyunsaturated 3.798 g
0 g
Vitamins
Vitamin E
(274%)

41.08 mg

Vitamin K
(5%)

5.4 μg

Percentages are roughly approximated using US recommendations for adults.
Source: USDA Nutrient Database
Sunflower oil, standard
Nutritional value per 100 g (3.5 oz)
Energy 3,699 kJ (884 kcal)
0 g
100 g
Saturated 10.3 g
Monounsaturated 19.5 g
Polyunsaturated 65.7 g
0 g
Vitamins
Vitamin E
(274%)

41.08 mg

Vitamin K
(5%)

5.4 μg

Percentages are roughly approximated using US recommendations for adults.
Source: USDA Nutrient Database
Sunflower oil (NuSun), mid oleic
Nutritional value per 100 g (3.5 oz)
Energy 3,699 kJ (884 kcal)
0 g
100 g
Saturated 9.009 g
Monounsaturated 57.344 g
Polyunsaturated 28.962 g
0 g
Vitamins
Vitamin E
(274%)

41.08 mg

Vitamin K
(5%)

5.4 μg

Percentages are roughly approximated using US recommendations for adults.
Source: USDA Nutrient Database

Several varieties of sunflower oilseeds have been developed by standard plant breeding methods, mainly to vary the amount of oleic acid and linoleic acid which, respectively, are the predominant monounsaturated and polyunsaturated fats in sunflower oil.[10]

While the original oilseed was high in linoleic acid, a polyunsaturated ω-6 fatty acid, a premium high oleic acid strain was developed in the late twentieth century.[10] Early in the 21st century, a mid-oleic strain marketed as Nu-Sun was introduced as an improved frying oil that would have a low level of saturated fat, but would not require hydrogenation.[10] These three major strains have been purposely bred to differ in their levels of monounsaturated and polyunsaturated fats, saturated fat and tocopherols.[10] All seed hybrids and the resulting different sunflower oils are mostly devoid of essential nutrients, with the notable exception of vitamin E which is high in content in all varieties (nutrient tables).

Comparative properties of common cooking fats (per 100 g )
Type of fat Total fat (g) Saturated fat (g) Monounsaturated fat (g) Polyunsaturated fat (g) Smoke point
Sunflower oil 100 11 20 69 225 °C (437 °F)[11]
Sunflower oil (high oleic) 100 12 84 [12] 4 [12]
Soybean oil 100 16 23 58 257 °C (495 °F)[11]
Canola oil 100 7 63 28 205 °C (401 °F)[12][13]
Olive oil 100 14 73 11 190 °C (374 °F)[11]
Corn oil 100 15 30 55 230 °C (446 °F)[11]
Peanut oil 100 17 46 32 225 °C (437 °F)[11]
Rice bran oil 100 25 38 37 250 °C (482 °F)[14]
Vegetable shortening (hydrogenated) 71 23 8 37 165 °C (329 °F)[11]
Lard 100 39 45 11 190 °C (374 °F)[11]
Suet 94 52 32 3 200 °C (392 °F)
Butter 81 51 21 3 150 °C (302 °F)[11]
Coconut oil 100 86 6 2 177 °C (351 °F)

Preparation and storage

Because sunflower oil is primarily composed of healthier-but-less-stable polyunsaturated and monounsaturated fatty acids, it can be particularly susceptible to degradation by heat, air, and light (which trigger and accelerate oxidation. Keeping sunflower oil at low temperatures during manufacture and storage can help minimize rancidity and nutrient loss—as can storage in bottles that are made of either darkly-colored glass, or, plastic that has been treated with an ultraviolet light protectant.

Methods of extraction

A man standing in front of a field of sunflowers
This Ugandan farmer has received a grant to help buy the equipment necessary to extract oil from sunflower seeds. Producing sunflower oil will create jobs in the local area.

Sunflower oil can be extracted using chemical solvents (e.g., hexane), or expeller pressing (i.e., squeezed directly from sunflower seeds by crushing them).[15] "Cold-pressing"/expeller-pressing sunflower seed oil under low-temperature conditions is a preferred method, for those seeking an extraction process that doesn't involve chemical solvents, as well as for people following a raw foods diet.

Refined versus unrefined

Refining sunflower oil through solvent extraction, de-gumming, neutralization, and bleaching can make it more stable and suitable for high-temperature cooking; but, will also remove some of the oil's nutrients; flavor; color (resulting in a pale-yellow); free fatty acids; phospholipids; polyphenols; and, phytosterols. Unrefined sunflower oil is less heat-stable (and therefore well-suited to dishes that are either raw or cooked at low temperatures); but, will retain more of its original nutrient content, flavor, and color (light-amber).

Uses

In food preparation

Refined sunflower oil is used for low-to-extremely-high-temperature cooking. As a frying oil, it behaves as a typical vegetable triglyceride. Unrefined sunflower oil is a traditional salad dressing in Eastern European cuisines. Sunflower oil is also an ingredient in sunflower butter. It may also help food stay fresher and healthier for longer periods of time.[16]

Some common snack foods currently contain sunflower oil, such as potato chips.

Supplements

Taking sunflower oil dietary supplements is not an effective treatment for eczema.[17]

As fuel

Sunflower oil can be used to run diesel engines when mixed with diesel in the tank. Due to the high levels of unsaturated fats, there is higher viscosity in cold temperatures.[18]

References

  1. UN Food & Agriculture Organisation (FAO)
  2. Christov, M. 2012. Contribution of interspecific hybridization to sunflower breeding. Helia. 35(57): 37- 46. Doi: 10.2298/hel1257037c. http://www.doiserbia.nb.rs/img/doi/1018-1806/2012/1018-18061257037C.pdf
  3. Alfred Thomas (2002). "Fats and Fatty Oils". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a10_173.
  4. British Pharmacopoeia Commission. "Ph Eur monograph 1371". British Pharmacopoeia 2005. Norwich, England: The Stationery Office. ISBN 0-11-322682-9.
  5. "Sunflower Oil - Your Healthy Choice". National Sunflower Association. Retrieved 26 June 2013.
  6. National Sunflower Association : Health and Nutrition
  7. 1 2 Chu, Michael (2004-06-10). "Smoke Points of Various Fats - Kitchen Notes". Cooking For Engineers. Retrieved 2013-02-07.
  8. 1 2 Irina NITA, Anisoara NEAGU, Sibel GEACAI, Anca DUMITRU and Anca STERPU: "Study of the behavior of some vegetable oils during the thermal treatment," Technology and Chemical Engineering Department, Ovidius University, bd. Mamaia 124, Constanta, 900527, Romania http://www.univ-ovidius.ro/anale-chimie/chemistry/2010-1/full/1_nita.pdf
  9. H. Abramovic and C. Klofutar (1998). "The Temperature Dependence of Dynamic Viscosity for Some Vegetable Oils" (PDF). Acta Chim. Slov. (Acta.chem-soc.si) 45 (1): 69–77. Retrieved 2013-02-07.
  10. 1 2 3 4 Skorić D, Jocić S, Sakac Z, Lecić N (2008). "Genetic possibilities for altering sunflower oil quality to obtain novel oils". Can J Physiol Pharmacol 86 (4): 215–21. doi:10.1139/Y08-008. PMID 18418432.
  11. 1 2 3 4 5 6 7 8 The Culinary Institute of America (2011). The Professional Chef (9th ed.). Hoboken, New Jersey: John Wiley & Sons. ISBN 978-0-470-42135-2. OCLC 707248142.
  12. 1 2 3 "Nutrient database, Release 25". United States Department of Agriculture.
  13. Katragadda, H. R.; Fullana, A. S.; Sidhu, S.; Carbonell-Barrachina, Á. A. (2010). "Emissions of volatile aldehydes from heated cooking oils". Food Chemistry 120: 59. doi:10.1016/j.foodchem.2009.09.070.
  14. http://alfaone.ca/rice-bran-oil-faq/
  15. Cox, Jeff (April 1979). "The Sunflower Seed Huller and Oil Press". Organic Gardening. Rodale Press. Retrieved 26 June 2013.
  16. New Healthful Sunflower Oil Resists Breakdown / June 11, 1998 / News from the USDA Agricultural Research Service
  17. Bath-Hextall FJ, Jenkinson C, Humphreys R, Williams HC (2012). "Dietary supplements for established atopic eczema". Cochrane Database Syst Rev (Systematic review) 2: CD005205. doi:10.1002/14651858.CD005205.pub3. PMID 22336810.
  18. Johnson, JJ. Meyer, RF. Krall, JM. Shroyer, JP. Schlegel, AJ. Falk, JS and Lee, CD. 2005. Agronomic Practices. In High Plains Sunflower Production Handbook. Kansas State University, Manhattan, KS [accessed 2014 October 22].
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