Fat hydrogenation
Types of fats in food |
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Components |
Manufactured fats |
Fat hydrogenation is the process of combining unsaturated fat with hydrogen in order to partially or completely convert it into saturated fat. Typically this hydrogenation is done with liquid vegetable oils resulting in solid or semi-solid fats.
Changing the degree of saturation of the fat changes some important physical properties, such as the melting range, which is why liquid oils become semi-solid. Solid or semi-solid fats are preferred for baking because the way the fat mixes with flour produces a more desirable texture in the baked product. Because partially hydrogenated vegetable oils are cheaper than animal fats, are available in a wide range of consistencies, and have other desirable characteristics such as increased oxidative stability and longer shelf life, they are the predominant fats used as shortening in most commercial baked goods.
The process is typically carried out at very high pressure, with the help of a nickel catalyst that is removed from the final product.
Process
Hydrogenating vegetable oil is done by raising a blend of vegetable oil and a metal catalyst, typically nickel, in near-vacuum to very high temperatures, and introducing hydrogen. This causes the carbon atoms of the oil to break double-bonds with other carbons. Each carbon atom becomes single-bonded to an individual hydrogen atom, and the double bond between carbons can no longer exist.
Full hydrogenation results in the conversion of all of the unsaturated fats into saturated fats by transforming all of the double bonds in the fat into single bonds. Partial hydrogenation reduces some, but not all, of the double bonds by the partial replacement with single bonds. The degree of hydrogenation is controlled by restricting the amount of hydrogen, reaction temperature and time, and the catalyst.[1]
Issues
Numerous studies have concluded that these trans fatty acids have negative health effects. As a result, many countries have enacted
A number of old and new ingredients are available to replace partially-hydrogenated oil with significant levels of trans fat.[2]
- Improved hydrogenation processes can produce partially-hydrogenated oil with much lower amounts of trans fat.[2]
- Oils rich in monounsaturated fatty acids (especially oleic acid) obtained from plant breeding have higher stability compared to their polyunsaturated-rich ancestors, offering a similar improvement to shelf life.[2]
- Tropical oils (palm oil, palm kernel oil, coconut oil) are naturally rich in saturated fat. They can be further fractionated to increase the concentration of desired fatty acids.[2]
- Interesterification can be used to mix multiple types of fats, obtaining an oil with intermediate properties. For example, soybean oil and fully-hydrogenated soybean oil can be interesterified to obtain a semi-hard oil.[2]
Dietary recommendations
Many health organizations recommend limiting or replacing dietary intake of
History
In 1909, Procter & Gamble acquired the United States rights to the Normann patent.[12] In 1911, they began marketing the first hydrogenated shortening, Crisco, composed largely of partially hydrogenated cottonseed oil. Further success came from the marketing technique of giving away free cookbooks in which every recipe called for Crisco.
In the early 20th century, soybeans began to be imported into the United States as a source of protein; large quantities of soybean oil were a by-product. At the same time, there was not enough butterfat available for consumers. Margarine manufacturers found that hydrogenated fats worked better than the previously used combination of animal and liquid vegetable fats. Margarine made from hydrogenated soybean oil and vegetable shortenings such as Crisco and Spry, sold in England, began to replace butter and lard in baking bread, pies, cookies, and cakes by 1920.[13]
Production of hydrogenated fats increased steadily until the 1960s, as processed vegetable fats replaced animal fats in the United States and other Western countries. At first, the argument was a financial one due to lower costs; advocates also said that the hydrogenated fats of margarine were healthier than the saturated fats of butter.[14]
Since then the food industry has moved away from partially hydrogenated fats in response to the health concerns about trans fats, labeling requirements, and removal of trans fats from permitted food additives.
See also
References
- ^ PMID 16720128.
- ^ "Deadly fats: why are we still eating them?". The Independent. 2008-06-10. Archived from the original on 2008-06-14. Retrieved 2008-06-16.
- ^ "New York City passes trans fat ban". NBC News. 2006-12-05. Retrieved 2010-01-09.
- ^ "F.D.A. Gives Food Industry 3 Years to Eliminate Trans Fats". The New York Times. 2015-06-16. Archived from the original on 2015-06-16. Retrieved 2015-06-16.
- S2CID 367602.the World Health Organization, Health Canada,"Choosing foods with healthy fats". Health Canada. 2018-10-10. Retrieved 2019-09-24., the US Department of Health and Human Services,"Cut Down on Saturated Fats" (PDF). United States Department of Health and Human Services. Retrieved 2019-09-24. the UK National Health Service,"Fat: the facts". United Kingdom's National Health Service. 2018-04-27. Retrieved 2019-09-24. the UK Scientific Advisory Committee on Nutrition "Saturated Fats and Health". Scientific Advisory Committee on Nutrition (SACN). Retrieved 26 July 2021], the Australian Department of Health and Aging,"Fat". Australia's National Health and Medical Research Council and Department of Health and Ageing. 2012-09-24. Retrieved 2019-09-24. the Singapore Ministry of Health,"Getting the Fats Right!". Singapore's Ministry of Health. Retrieved 2019-09-24. the Indian Ministry of Health and Family Welfare,"Health Diet". India's Ministry of Health and Family Welfare. Retrieved 2019-09-24. the New Zealand Ministry of Health,"Making healthier food choices". New Zealand's Ministry of Health. Retrieved 2021-06-03. and Hong Kong's Department of Health."Know More about Fat". Hong Kong's Department of Health. Retrieved 2019-09-24.
- ^ Nobel Lectures, Chemistry, 1901–1921. Elsevier. 1966. Reprinted online: "Paul Sabatier, The Nobel Prize in Chemistry 1912". Nobel Foundation. Retrieved 7 January 2007.
- ^ de 141029 Process for converting unsaturated fatty acids or their glycerides into saturated compounds
- ^ gb 190301515 Process for converting unsaturated fatty acids or their glycerides into saturated compounds
- ^ Patterson HB (1998). "Hydrogenation" (PDF). Sci Lecture Papers Series. Archived from the original (PDF) on 26 September 2007. Retrieved 7 January 2007.
- ^ a b "Wilhelm Normann und die Geschichte der Fetthärtung von Martin Fiedler, 2001". 20 December 2011. Archived from the original on 1 October 2011. Retrieved 14 August 2007.
- ^ Shurtleff W, Aoyagi A. "History of Soybeans and Soyfoods: 1100 B.C. to the 1980s". Archived from the original on 18 October 2005.
- ISBN 978-1-4251-3808-0. NOTE: Unreliable source.
- PMID 10379026. Archived from the originalon 3 September 2006. Retrieved 14 September 2006.
- ^ "Ask the Experts: Hydrogenated Oils". Berkeley Wellness. Remedy Health Media. October 1, 2011. Retrieved 24 November 2018.
- United States Pharmacopeial Convention. Retrieved 24 November 2018.
- Dotdash. Retrieved 24 November 2018.
External links
- Shurtleff, William; Aoyagi, Akiko (2020). History of Hydrogenation, Shortening and Margarine (1860-2020): Extensively Annotated Bibliography and Sourcebook (PDF). Lafayette, CA: Soyinfo Center. ISBN 9781948436182.