Polyunsaturated fat
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Polyunsaturated fatty acids (PUFAs) are fatty acids that contain more than one double bond in their backbone. This class includes many important compounds, such as essential fatty acids and those that give drying oils their characteristic property.
Polyunsaturated fatty acids can be classified in various groups by their chemical structure:
- methylene-interrupted polyenes
- conjugated fatty acids
- other PUFAs
Based on the length of their carbon backbone, they are sometimes classified in two groups:[1]
- short chain polyunsaturated fatty acids (SC-PUFA), with 18 carbon atoms
- long-chain polyunsaturated fatty acids (LC-PUFA) with 20 or more carbon atoms
Dietary sources
| Type | Processing treatment[4] |
Saturated fatty acids |
Monounsaturated fatty acids |
Polyunsaturated fatty acids |
Smoke point | ||||
|---|---|---|---|---|---|---|---|---|---|
| Total[2] | Oleic acid (ω-9) |
Total[2] | α-Linolenic acid (ω-3) |
Linoleic acid (ω-6) |
ω-6:3 ratio | ||||
| Avocado[5] | 11.6 | 70.6 | 52–66 [6] |
13.5 | 1 | 12.5 | 12.5:1 | 250 °C (482 °F)[7] | |
| Brazil nut[8] | 24.8 | 32.7 | 31.3 | 42.0 | 0.1 | 41.9 | 419:1 | 208 °C (406 °F)[9] | |
| Canola[10] | 7.4 | 63.3 | 61.8 | 28.1 | 9.1 | 18.6 | 2:1 | 204 °C (400 °F)[11] | |
| Coconut[12] | 82.5 | 6.3 | 6 | 1.7 | 0.019 | 1.68 | 88:1 | 175 °C (347 °F)[9] | |
| Corn[13] | 12.9 | 27.6 | 27.3 | 54.7 | 1 | 58 | 58:1 | 232 °C (450 °F)[11] | |
| Cottonseed[14] | 25.9 | 17.8 | 19 | 51.9 | 1 | 54 | 54:1 | 216 °C (420 °F)[11] | |
| Cottonseed[15] | hydrogenated | 93.6 | 1.5 | 0.6 | 0.2 | 0.3 | 1.5:1 | ||
| Flaxseed/linseed[16] | 9.0 | 18.4 | 18 | 67.8 | 53 | 13 | 0.2:1 | 107 °C (225 °F) | |
| Grape seed | 10.4 | 14.8 | 14.3 | 74.9 | 0.15 | 74.7 | very high | 216 °C (421 °F)[17] | |
| Hemp seed[18] | 7.0 | 9.0 | 9.0 | 82.0 | 22.0 | 54.0 | 2.5:1 | 166 °C (330 °F)[19] | |
| High-oleic safflower oil[20] | 7.5 | 75.2 | 75.2 | 12.8 | 0 | 12.8 | very high | 212 °C (414 °F)[9] | |
| Olive, Extra Virgin[21] | 13.8 | 73.0 | 71.3 | 10.5 | 0.7 | 9.8 | 14:1 | 193 °C (380 °F)[9] | |
| Palm[22] | 49.3 | 37.0 | 40 | 9.3 | 0.2 | 9.1 | 45.5:1 | 235 °C (455 °F) | |
| Palm[23] | hydrogenated | 88.2 | 5.7 | 0 | |||||
| Peanut[24] | 16.2 | 57.1 | 55.4 | 19.9 | 0.318 | 19.6 | 61.6:1 | 232 °C (450 °F)[11] | |
| Rice bran oil | 25 | 38.4 | 38.4 | 36.6 | 2.2 | 34.4[25] | 15.6:1 | 232 °C (450 °F)[26] | |
| Sesame[27] | 14.2 | 39.7 | 39.3 | 41.7 | 0.3 | 41.3 | 138:1 | ||
| Soybean[28] | 15.6 | 22.8 | 22.6 | 57.7 | 7 | 51 | 7.3:1 | 238 °C (460 °F)[11] | |
| Soybean[29] | partially hydrogenated | 14.9 | 43.0 | 42.5 | 37.6 | 2.6 | 34.9 | 13.4:1 | |
| Sunflower[30] | 8.99 | 63.4 | 62.9 | 20.7 | 0.16 | 20.5 | 128:1 | 227 °C (440 °F)[11] | |
| Walnut oil[31] | unrefined | 9.1 | 22.8 | 22.2 | 63.3 | 10.4 | 52.9 | 5:1 | 160 °C (320 °F)[32] |
Types
Methylene-interrupted polyenes
These fatty acids have 2 or more cis double bonds that are separated from each other by a single methylene bridge (-CH
2-). This form is also sometimes called a divinylmethane pattern.[33]
| −C−C=C−C−C=C− |
The essential fatty acids are all omega-3 and -6 methylene-interrupted fatty acids. See more at Essential fatty acids—Nomenclature
Omega-3
| Common name | Lipid name | Chemical name |
|---|---|---|
| Hexadecatrienoic acid (HTA) | 16:3 (n-3) | all-cis 7,10,13-hexadecatrienoic acid |
| Alpha-linolenic acid (ALA) | 18:3 (n-3) | all-cis-9,12,15-octadecatrienoic acid |
| Stearidonic acid (SDA) | 18:4 (n-3) | all-cis-6,9,12,15,-octadecatetraenoic acid |
| Eicosatrienoic acid (ETE) | 20:3 (n-3) | all-cis-11,14,17-eicosatrienoic acid |
| Eicosatetraenoic acid (ETA) | 20:4 (n-3) | all-cis-8,11,14,17-eicosatetraenoic acid |
| Eicosapentaenoic acid (EPA, Timnodonic acid) | 20:5 (n-3) | all-cis-5,8,11,14,17-eicosapentaenoic acid |
| Heneicosapentaenoic acid (HPA) | 21:5 (n-3) | all-cis-6,9,12,15,18-heneicosapentaenoic acid |
| Docosapentaenoic acid (DPA, Clupanodonic acid) | 22:5 (n-3) | all-cis-7,10,13,16,19-docosapentaenoic acid |
| Docosahexaenoic acid (DHA, Cervonic acid) | 22:6 (n-3) | all-cis-4,7,10,13,16,19-docosahexaenoic acid |
| Tetracosapentaenoic acid | 24:5 (n-3) | all-cis-9,12,15,18,21-tetracosapentaenoic acid |
| Tetracosahexaenoic acid (Nisinic acid) | 24:6 (n-3) | all-cis-6,9,12,15,18,21-tetracosahexaenoic acid |
Omega-6
| Common name | Lipid name | Chemical name |
|---|---|---|
| Linoleic acid (LA) | 18:2 (n-6) | all-cis-9,12-octadecadienoic acid |
| Gamma-linolenic acid (GLA) | 18:3 (n-6) | all-cis-6,9,12-octadecatrienoic acid |
| Eicosadienoic acid | 20:2 (n-6) | all-cis-11,14-eicosadienoic acid |
| Dihomo-gamma-linolenic acid (DGLA) | 20:3 (n-6) | all-cis-8,11,14-eicosatrienoic acid |
| Arachidonic acid (AA) | 20:4 (n-6) | all-cis-5,8,11,14-eicosatetraenoic acid |
| Docosadienoic acid | 22:2 (n-6) | all-cis-13,16-docosadienoic acid |
| Adrenic acid (AdA) | 22:4 (n-6) | all-cis-7,10,13,16-docosatetraenoic acid |
| Docosapentaenoic acid (DPA) | 22:5 (n-6) | all-cis-4,7,10,13,16-docosapentaenoic acid |
| Tetracosatetraenoic acid | 24:4 (n-6) | all-cis-9,12,15,18-tetracosatetraenoic acid |
| Tetracosapentaenoic acid | 24:5 (n-6) | all-cis-6,9,12,15,18-tetracosapentaenoic acid |
Omega-9
| Common name | Lipid name | Chemical name |
|---|---|---|
| Oleic acid† | 18:1 (n-9) | cis-9-octadecenoic acid |
| Eicosenoic acid† | 20:1 (n-9) | cis-11-eicosenoic acid |
| Mead acid | 20:3 (n-9) | all-cis-5,8,11-eicosatrienoic acid |
| Erucic acid† | 22:1 (n-9) | cis-13-docosenoic acid |
| Nervonic acid† | 24:1 (n-9) | cis-15-tetracosenoic acid |
| †Monounsaturated | ||
Conjugated fatty acids
| -C=C-C=C- |
| Common name | Lipid name | Chemical name |
|---|---|---|
| Conjugated Linoleic Acids (two conjugated double bonds) | ||
| Rumenic acid | 18:2 (n-7) | 9Z,11E-octadeca-9,11-dienoic acid |
| 18:2 (n-6) | 10E,12Z-octadeca-10,12-dienoic acid | |
| Conjugated Linolenic Acids (three conjugated double bonds) | ||
| α-Calendic acid | 18:3 (n-6) | 8E,10E,12Z-octadecatrienoic acid |
| β-Calendic acid | 18:3 (n-6) | 8E,10E,12E-octadecatrienoic acid |
| Jacaric acid | 18:3 (n-6) | 8Z,10E,12Z-octadecatrienoic acid |
| α-Eleostearic acid | 18:3 (n-5) | 9Z,11E,13E-octadeca-9,11,13-trienoic acid |
| β-Eleostearic acid | 18:3 (n-5) | 9E,11E,13E-octadeca-9,11,13-trienoic acid |
| Catalpic acid | 18:3 (n-5) | 9Z,11Z,13E-octadeca-9,11,13-trienoic acid |
| Punicic acid | 18:3 (n-5) | 9Z,11E,13Z-octadeca-9,11,13-trienoic acid |
| Other | ||
| Rumelenic acid | 18:3 (n-3) | 9E,11Z,15E-octadeca-9,11,15-trienoic acid |
| α-Parinaric acid | 18:4 (n-3) | 9E,11Z,13Z,15E-octadeca-9,11,13,15-tetraenoic acid |
| β-Parinaric acid | 18:4 (n-3) | all trans-octadeca-9,11,13,15-tetraenoic acid |
| Bosseopentaenoic acid | 20:5 (n-6) | 5Z,8Z,10E,12E,14Z-eicosapentaenoic acid |
Other polyunsaturated fatty acids
| Common name | Lipid name | Chemical name |
|---|---|---|
| Pinolenic acid | 18:3 (n-6) | (5Z,9Z,12Z)-octadeca-5,9,12-trienoic acid |
| Sciadonic acid | 20:3 (n-6) | (5Z,11Z,14Z)-eicosa-5,11,14-trienoic acid |
Function and effects
The biological effects of the ω-3 and ω-6 fatty acids are largely mediated by their mutual interactions, see Essential fatty acid interactions for detail.
Thermal degradation
Polyunsaturated fatty acids in culinary oils undergo oxidative deterioration at temperatures of 150 °C (302 °F). The heating causes a free radical chain reaction, which oxidizes the PUFAs into hydroperoxide, which further decomposes into a complex mixture of secondary products.[34]
See also
References
Citations
- ^ Buckley MT, et al. (2017). "Selection in Europeans on Fatty Acid Desaturases Associated with Dietary Changes". Mol Biol Evol. 34 (6): 1307–1318. doi:10.1093/molbev/msx103. PMC 5435082. PMID 28333262.
- ^ a b c "US National Nutrient Database, Release 28". United States Department of Agriculture. May 2016. All values in this table are from this database unless otherwise cited or when italicized as the simple arithmetic sum of other component columns.
- ^ "Fats and fatty acids contents per 100 g (click for "more details"). Example: Avocado oil (user can search for other oils)". Nutritiondata.com, Conde Nast for the USDA National Nutrient Database, Standard Release 21. 2014. Retrieved 7 September 2017. Values from Nutritiondata.com (SR 21) may need to be reconciled with most recent release from the USDA SR 28 as of Sept 2017.
- ^ "USDA Specifications for Vegetable Oil Margarine Effective August 28, 1996" (PDF).
- ^ "Avocado oil, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ Ozdemir F, Topuz A (2004). "Changes in dry matter, oil content and fatty acids composition of avocado during harvesting time and post-harvesting ripening period" (PDF). Food Chemistry. Elsevier. pp. 79–83. Archived from the original (PDF) on 2020-01-16. Retrieved 15 January 2020.
- ^ Wong M, Requejo-Jackman C, Woolf A (April 2010). "What is unrefined, extra virgin cold-pressed avocado oil?". Aocs.org. The American Oil Chemists' Society. Retrieved 26 December 2019.
- ^ "Brazil nut oil, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ a b c d Katragadda HR, Fullana A, Sidhu S, Carbonell-Barrachina ÁA (2010). "Emissions of volatile aldehydes from heated cooking oils". Food Chemistry. 120: 59–65. doi:10.1016/j.foodchem.2009.09.070.
- ^ "Canola oil, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ a b c d e f Wolke RL (May 16, 2007). "Where There's Smoke, There's a Fryer". The Washington Post. Retrieved March 5, 2011.
- ^ "Coconut oil, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ "Corn oil, industrial and retail, all purpose salad or cooking, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ "Cottonseed oil, salad or cooking, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ "Cottonseed oil, industrial, fully hydrogenated, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ "Linseed/Flaxseed oil, cold pressed, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ Garavaglia J, Markoski MM, Oliveira A, Marcadenti A (2016). "Grape Seed Oil Compounds: Biological and Chemical Actions for Health". Nutrition and Metabolic Insights. 9: 59–64. doi:10.4137/NMI.S32910. PMC 4988453. PMID 27559299.
- ^ Callaway J, Schwab U, Harvima I, Halonen P, Mykkänen O, Hyvönen P, Järvinen T (April 2005). "Efficacy of dietary hempseed oil in patients with atopic dermatitis". The Journal of Dermatological Treatment. 16 (2): 87–94. doi:10.1080/09546630510035832. PMID 16019622. S2CID 18445488.
- ^ Melina V. "Smoke points of oils" (PDF). veghealth.com. The Vegetarian Health Institute.
- ^ "Safflower oil, salad or cooking, high oleic, primary commerce, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ "Olive oil, salad or cooking, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ "Palm oil, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ "Palm oil, industrial, fully hydrogenated, filling fat, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ "Oil, peanut". FoodData Central. usda.gov.
- ^ Orthoefer FT (2005). "Chapter 10: Rice Bran Oil". In Shahidi F (ed.). Bailey's Industrial Oil and Fat Products. Vol. 2 (6th ed.). John Wiley & Sons, Inc. p. 465. doi:10.1002/047167849X. ISBN 978-0-471-38552-3.
- ^ "Rice bran oil". RITO Partnership. Retrieved 22 January 2021.
- ^ "Oil, sesame, salad or cooking". FoodData Central. fdc.nal.usda.gov. 1 April 2019.
- ^ "Soybean oil, salad or cooking, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ "Soybean oil, salad or cooking, (partially hydrogenated), fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017.
- ^ "FoodData Central". fdc.nal.usda.gov.
- ^ "Walnut oil, fat composition, 100 g". US National Nutrient Database, United States Department of Agriculture.
- ^ "Smoke Point of Oils". Baseline of Health. Jonbarron.org.
- ^ Baggott, James (1997). The divinylmethane pattern in fatty acids. Salt Lake City, UT: Knowledge Weavers.
- ^ Moya Moreno, MC; Mendoza Olivares, D; Amézquita López, FJ; Gimeno Adelantado, JV; Bosch Reig, F (September 13, 1999). "Analytical evaluation of polyunsaturated fatty acids degradation during thermal oxidation of edible oils by Fourier transform infrared spectroscopy". Talanta. 50 (2): 269–75. doi:10.1016/S0039-9140(99)00034-X. PMID 18967717.
General References
- Cyberlipid. "Polyenoic Fatty Acids". Archived from the original on 2018-09-30. Retrieved 2007-01-17.
- Gunstone, Frank D. "Lipid Glossary 2" (PDF). Archived from the original (PDF) on 2006-08-13. Retrieved 2007-01-17.
- Adlof, R. O. & Gunstone, F. D. (2003-09-17). "Common (non-systematic) Names for Fatty Acids". Archived from the original on 2006-12-06. Retrieved 2007-01-24.
- Heinz; Roughan, PG (1983). "Similarities and Differences in Lipid Metabolism of Chloroplasts Isolated from 18:3 and 16:3 Plants". Plant Physiol. 72 (2): 273–279. doi:10.1104/pp.72.2.273. PMC 1066223. PMID 16662992.