Smoke point
The smoke point of an oil or fat is the temperature at which, under defined conditions, enough volatile compounds emerge when a bluish smoke becomes clearly visible from the oil. At this temperature, volatile compounds, such as free fatty acids, and short-chain degradation products of oxidation come up from the oil. These volatile compounds degrade in air to give soot. The smoke point indicates the temperature limit up to which that cooking oil can be used.[1]
The smoke point correlates with the amount of free fatty acid in an oil.[1] It varies widely, depending on origin and refinement.[2] The smoke point of an oil does tend to increase as free fatty acid content decreases and degree of refinement increases.[3][4] Heating the oil produces free fatty acid and as this heating time increases, more free fatty acids are produced, thereby decreasing smoke point. It is one reason not to use the same oil to deep fry more than twice.[2] Intermittent frying has a markedly greater effect on oil deterioration than continuous frying.[5]
Considerably above the temperature of the smoke point is the flash point, the point at which the vapours from the oil can first ignite when mixed with air.
The following table presents smoke points of various fats:
| Fat | Quality | Smoke Point | |
|---|---|---|---|
| Almond oil | 216°C | 420°F | |
| Avocado oil | 270°C | 520°F[6][7] | |
| Butter | 150°C | 302°F[8] | |
| Canola oil (Rapeseed) | Expeller Press | 190-232°C | 375-450°F[9] |
| Canola oil (Rapeseed) | High Oleic | 246°C | 475°F |
| Canola oil (Rapeseed) | Refined | 204°C[2] | 400°F |
| Canola oil (Rapeseed) | Unrefined | 107°C[2] | 225°F |
| Castor oil | Refined | 200°C[10] | 392°F |
| Coconut oil | Dry Expeller Pressed Virgin (Unrefined) | 177°C | 350°F[11] |
| Coconut oil | Dry Refined | 204°C | 400°F[12] |
| Corn oil | Unrefined | 178°C[10] | 352°F |
| Corn oil | Refined | 232°C[2] | 450°F |
| Cottonseed oil | 216°C[2] | 420°F | |
| Flaxseed oil | Unrefined | 107°C | 225°F[13] |
| Ghee (Indian Clarified Butter) | 252°C | 485°F | |
| Grapeseed oil | 216°C | 420°F | |
| Hazelnut oil | 221°C | 430°F | |
| Hemp oil | 165°C | 330°F | |
| Lard | 190°C | 374°F[8] | |
| Macadamia oil | 210°C | 413°F | |
| Mustard oil | 254°C | 489°F | |
| Olive oil | Extra virgin | 160°C | 320°F[6][7] |
| Olive oil | Virgin | 210°C[10] | 410°F |
| Olive oil, high quality (low acidity) | Extra virgin | 207°C | 405°F[14] |
| Olive Pomace Oil | 238°C[2] | 460°F | |
| Palm oil | Difractionated | 235°C[15] | 455°F |
| Peanut oil | Unrefined | 160°C | 320°F |
| Peanut oil | Refined | 232°C[2] | 450°F |
| Rice bran oil | 254°C | 490°F | |
| Safflower oil | Unrefined | 107°C | 225°F |
| Safflower oil | Semirefined | 160°C | 320°F |
| Safflower oil | Refined | 266°C[2] | 510°F |
| Sesame oil | Unrefined | 177°C | 350°F[16] |
| Sesame oil | Semirefined | 232°C | 450°F[17] |
| Soybean oil | Unrefined | 160°C | 320°F |
| Soybean oil | Semirefined | 177°C | 350°F |
| Soybean oil | Refined | 238°C[2] | 460°F |
| Sunflower oil | Unrefined | 107°C | 225°F |
| Sunflower oil | Semirefined | 232°C | 450°F |
| Sunflower oil | Refined | 227°C[2] | 440°F |
| Sunflower oil, high oleic | Unrefined | 160°C | 320°F |
| Tallow (Beef) | 215°C | 420°F | |
| Tea seed oil | 252°C | 485°F | |
| Vegetable shortening | 182°C | 360°F | |
| Walnut oil | Unrefined | 160°C | 320°F |
| Walnut oil | Semirefined | 204°C | 400°F |
See also
- Boiling point
- Flash point
- Fire point
- Kindling point (Autoignition temperature)
References
- 1 2 Alfred Thomas (2002). "Fats and Fatty Oils". Ullmann's Encyclopedia of Industrial Chemistry. Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a10_173. ISBN 3-527-30673-0.
- 1 2 3 4 5 6 7 8 9 10 11 Wolke, Robert L. (May 16, 2007). "Where There's Smoke, There's a Fryer". The Washington Post. Retrieved March 5, 2011.
- ↑ Morgan, D. A. (1942). "Smoke, fire, and flash points of cottonseed, peanut, and other vegetable oils". Oil & Soap 19 (11): 193. doi:10.1007/BF02545481.
- ↑ Bockisch, Michael (1998). Fats and Oils Handbook. Champaign, IL: AOCS Press. pp. 95–6. ISBN 0-935315-82-9.
- ↑ Amit K. Das, et al, http://www.slideshare.net/amitkdas12/study-of-oil-deterioration-during-continuous-and-intermittent-frying
- 1 2 "Smoking Points of Fats and Oils." http://whatscookingamerica.net/Information/CookingOilTypes.htm
- 1 2 http://jonbarron.org/diet-and-nutrition/healthiest-cooking-oil-chart-smoke-points#.VTM7A-HBUbA
- 1 2 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.
- ↑ Spectrum Organics, Canola Oil Manufacturer, http://www.spectrumorganics.com/shared/faq.php?fqid=34
- 1 2 3 Detwiler, S. B.; Markley, K. S. (1940). "Smoke, flash, and fire points of soybean and other vegetable oils". Oil & Soap 17 (2): 39–40. doi:10.1007/BF02543003.
- ↑ Nutiva, Coconut Oil Manufacturer, http://nutiva.com/introducing-nutiva-refined-coconut-oil/
- ↑ Nutiva, Coconut Oil Manufacturer, http://nutiva.com/introducing-nutiva-refined-coconut-oil/
- ↑ "Healthiest Cooking Oil Chart with Smoke Points." http://jonbarron.org/diet-and-nutrition/healthiest-cooking-oil-chart-smoke-points#.VTM7A-HBUbA
- ↑ http://jonbarron.org/diet-and-nutrition/healthiest-cooking-oil-chart-smoke-points#.VTM7A-HBUbA
- ↑ (Italian) Scheda tecnica dell'olio di palma bifrazionato PO 64.
- ↑ http://jonbarron.org/diet-and-nutrition/healthiest-cooking-oil-chart-smoke-points#.VTM7A-HBUbA
- ↑ http://jonbarron.org/diet-and-nutrition/healthiest-cooking-oil-chart-smoke-points#.VTM7A-HBUbA
- Cooking For Engineers: Smoke Point of Various Fats - another list of smoke points along with some discussion on the subject
- Good Eats: Cooking Oil Smoke Points
- The Culinary Institute of America (1996). The New Professional Chef (6th ed.). John Wiley & Sons.