Smoke point

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The smoke point of an oil or fat is the temperature at which, under specific and defined conditions, an oil begins to produce a continuous bluish smoke that becomes clearly visible.[1] Smoke point values can vary greatly, depending on factors such as the volume of oil utilized, the size of the container, the presence of air currents, the type and source of light as well as the quality of the oil and its acidity content, otherwise known as free fatty acid (FFA) content.[2] The higher FFA in the oil to begin with, the quicker it will break down and start smoking.[2][3] The higher in quality and the lower in FFA, the higher the smoke point.[4] It is important to consider, however, that the FFA only represents typically less than 1% of the total oil and consequently renders smoke point a poor indicator of the capacity of a fat or oil to withstand heat.[4][5][6]

The smoke point of an oil correlates with their level of refinement.[7][8] Many cooking oils have smoke points above standard home cooking temperatures:


Standard Cooking Temperatures at Home[citation needed]

Pan frying (sauté) on stove top heat: 120 °C (248 °F)

Deep frying: 160 - 180 °C (320 °F - 356 °F)

Oven baking: Average of 180 °C (356 °F)


Smoke point decreases at different pace in different oils. [9]

Considerably above the temperature of the smoke point is the flash point, the point at which the vapours from the oil can ignite in air.

Oxidative stability[edit]

Hydrolysis and oxidation are the two primary degradation processes that occur in an oil during cooking. [9] Oxidative stability is how resistant an oil is to reacting with oxygen, breaking down and potentially producing harmful compounds while exposed to continuous heat. Oxidative stability is the best predictor of how an oil behaves during cooking .[10][11][12] The Rancimat® method is one of the most common methods for testing oxidative stability in oils.[12]This determination entails speeding up the oxidation process in the oil (under heat and forced air), which enables the oils’ stability to be evaluated by monitoring volatile substances associated with rancidity. It is measured as “Induction time” and recorded as total hours before the oil breaks down. Canola oil requires 7.5 hours, for example, whereas extra virgin olive oil (EVOO) and virgin coconut oil will last over a day at 110 °C of continuous heat.[13] The differing stabilities correlates with lower levels of polyunsaturated fatty acids, which are more prone to oxidation. EVOO is high in monounsaturated fatty acids and natural antioxidants, conferring stability.[13]

The following table presents smoke points and oxidative stability of various fats and oils:

Fat Quality Smoke Point
Almond oil 216°C[citation needed] 420°F
Avocado oil 270°C 520°F[14][15]
Butter 150°C 302°F[16]
Canola oil (Rapeseed) Expeller Press 190-232°C 375-450°F[17]
Canola oil (Rapeseed) Refined 204°C 400°F
Canola oil (Rapeseed) Unrefined 107°C 225°F
Castor oil Refined 200°C[18] 392°F
Coconut oil Dry Expeller Pressed Virgin (Unrefined) 177°C 350°F[19]
Coconut oil Dry Refined 204°C 400°F[19]
Corn oil Unrefined 178°C[18] 352°F
Flaxseed oil Unrefined 107°C 225°F[20]
Lard 190°C 374°F[16]
Olive oil Extra virgin 190°C 374°F[13]
Olive oil, high quality (low acidity) Extra virgin 207°C 405°F[21][13]
Olive oil Virgin 210°C[18] 410°F
Olive oil Refined 199° - 243°C 390⁰ - 470⁰F[22]
Palm oil Difractionated 235°C[23] 455°F
Sesame oil Unrefined 177°C 350°F[21]
Sesame oil Semirefined 232°C 450°F[21]
Sunflower oil Unrefined 107°C[24] 320°F
Vegetable oil blend Refined 220°C[13] 428°F

See also[edit]

References[edit]

  1. ^ American Oil Chemists' Society (2011). "AOCS Official Method Cc 9a-48, Smoke, Flash and Fire Points Cleveland Open Cup Method". Official methods and recommended practices of the AOCS - (6th ed.). Champaign, Ill. : American Oil Chemists' Society. 
  2. ^ a b Thomas, Alfred (2002). Fats and Fatty Oils. Ullmann's Encyclopedia of Industrial Chemistry. Wenheim: Wiley-VCH. ISBN 3-527-30673-0. 
  3. ^ Bastida, SS; et al. (2001). "Thermal oxidation of olive oil, sunflower oil and a mix of both oils during forty continuous domestic fryings of different foods". Food Sci Tech Int. 7: 15–21. doi:10.1106/1898-plw3-6y6h-8k22. 
  4. ^ a b Gennaro, L. et al., (1998). "Effect of biophenols on olive oil stability evaluated by thermogravimetric analysis.". Journal of Agricultural and Food Chemistry. 46: 4465-4469. doi:10.1021/jf980562q. 
  5. ^ Gomez-Alonso, S., et al, (2003). "Changes in phenolic composition and antioxidant activity of virgin olive oil during frying". J Agric Food Chem. 51: 667-372. doi:10.1021/jf025932w. PMID 12537439. 
  6. ^ Chen, W., et al, (2013). "Total polar compounds and acid values of repeatedly used frying oils measured by standard and rapid methods" (PDF). J Food Drug Anal. 21 (1): 85-85. 
  7. ^ Boickish, Michael (1998). Fats and oils handbook. Champaign, IL: AOCS Press. p. 95 - 96. ISBN 0-935315-82-9. 
  8. ^ Morgan, D.A. (1642). "Smoke, fire, and flash points of cottonseed, peanut, and other vegetable oils". Oil & Soap. 19 (11): 193–198. doi:10.1007/BF02545481. 
  9. ^ a b Monoj K. Gupta, Kathleen Warner, Pamela J. White (2004). Frying technology and Practices. AOCS Press, Champaign, Illinois. 
  10. ^ Fats and oils in human nutrition. Food and Agriculture Organization of the United Nations and the World Health Organization. 1994. ISBN 92-5-103621-7. 
  11. ^ Nwosu, V., et al,. Oxidative Stability of various oils as determined by Rancimat Method. Department of Food Science.: North Carolina State University. 
  12. ^ a b Methrom. "Oxidative stability of oils and fats - Rancimat method". Application Bulletin. 204/2 e. 
  13. ^ a b c d e Gray, S (June 2015). "Cooking with extra virgin olive oil" (PDF). ACNEM Journal. 34 (2): 8-12. 
  14. ^ "Smoking Points of Fats and Oils." http://whatscookingamerica.net/Information/CookingOilTypes.htm
  15. ^ "Smoke Point of Oils | Baseline of Health". Jonbarron.org. 2012-04-17. Retrieved 2016-05-28. 
  16. ^ a b 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.
  17. ^ Spectrum Organics, Canola Oil Manufacturer, http://www.spectrumorganics.com/shared/faq.php?fqid=34
  18. ^ a b c 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. 
  19. ^ a b Nutiva, Coconut Oil Manufacturer, http://nutiva.com/introducing-nutiva-refined-coconut-oil/
  20. ^ "Healthiest Cooking Oil Chart with Smoke Points." http://jonbarron.org/diet-and-nutrition/healthiest-cooking-oil-chart-smoke-points#.VTM7A-HBUbA
  21. ^ a b c "Smoke Point of Oils | Baseline of Health". Jonbarron.org. 2012-04-17. Retrieved 2016-05-28. 
  22. ^ "Olive Oil Smoke Point". Retrieved 2016-08-25. 
  23. ^ (Italian) Scheda tecnica dell'olio di palma bifrazionato PO 64.
  24. ^ "Organic unrefined sunflower oil". Retrieved 18 December 2016.