Fat hydrogenation

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Products with partially hydrogenated fat Avoiding Trans Fat (18520422550).jpg
Products with partially hydrogenated fat

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.

Contents

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 some baked goods such as biscuits and pie dough because how the fat mixes with flour produces a more desirable, crumbly 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.

The desirable (left) and undesirable pathways for partial hydrogenation of an unsaturated fat. Elaidic acid is a trans fat with negative health effects. FatHydrogenation.svg
The desirable (left) and undesirable pathways for partial hydrogenation of an unsaturated fat. Elaidic acid is a trans fat with negative health effects.

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

Cis–trans isomerization of some of the remaining unsaturated carbon bonds to their trans isomers during the partial hydrogenation process produces trans fat, which has been demonstrated to have cardiovascular health risk. [2] The conversion from cis to trans bonds is chemically favored because the trans configuration has lower energy than the natural cis one. At equilibrium, the trans/cis isomer ratio is about 2:1.

Numerous studies have concluded that these trans fatty acids have negative health effects. As a result, many countries have enacted trans fat regulation that aims to eliminate or severely restrict their amount in industrialized food products, such as mandatory labeling of trans fats on food products. [3] [4] The United States Food and Drug Administration has concluded that partially hydrogenated oils are not generally recognized as safe, and since 2018 categorizes them as food additives, not food. [5]

A number of old and new ingredients are available to replace partially-hydrogenated oil with significant levels of trans fat. [2]

Dietary recommendations

Many health organizations recommend limiting or replacing dietary intake of trans fats and saturated fats, in favor of unsaturated fats. [6]

History

Wilhelm Normann patented the hydrogenation of liquid oils in 1902 Wilhelm Normann.jpg
Wilhelm Normann patented the hydrogenation of liquid oils in 1902

Nobel laureate Paul Sabatier worked in the late 1890s to develop the chemistry of hydrogenation. [7] Whereas Sabatier considered hydrogenation of only vapors, the German chemist Wilhelm Normann showed in 1901 that liquid oils could be hydrogenated, and patented the process in 1902. [8] [9] [10] Normann's hydrogenation process made it possible to stabilize affordable whale oil or fish oil for human consumption, a practice kept secret to avoid consumer distaste. [11] During the years 1905–1910, Normann built a fat-hardening facility in the Herford company. At the same time, the invention was extended to a large-scale plant in Warrington, England, at Joseph Crosfield & Sons, Limited. It took only two years until the hardened fat could be successfully produced in the plant in Warrington, commencing production in late 1909. The initial year's production totalled nearly 3,000 tonnes. [11]

Cover of original Crisco cookbook, 1912 Crisco Cookbook 1912.jpg
Cover of original Crisco cookbook, 1912

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. [15] [16] [17] They have been replaced with fully hydrogenated fats, vegetable oils that are naturally higher in saturated fat and therefore more solid at room temperature, such as palm oil and coconut oil, and interesterified fats, which cannot result in the formation of trans fats.

See also

Related Research Articles

<span class="mw-page-title-main">Fatty acid</span> Carboxylic acid

In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, from 4 to 28. Fatty acids are a major component of the lipids in some species such as microalgae but in some other organisms are not found in their standalone form, but instead exist as three main classes of esters: triglycerides, phospholipids, and cholesteryl esters. In any of these forms, fatty acids are both important dietary sources of fuel for animals and important structural components for cells.

<span class="mw-page-title-main">Fat</span> Esters of fatty acid or triglycerides

In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food.

<span class="mw-page-title-main">Triglyceride</span> Any ester of glycerol having all three hydroxyl groups esterified with fatty acids

A triglyceride is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans and other vertebrates, as well as vegetable fat. They are also present in the blood to enable the bidirectional transference of adipose fat and blood glucose from the liver, and are a major component of human skin oils.

α-Linolenic acid Chemical compound

α-Linolenic acid, also known as alpha-linolenic acid (ALA), is an n−3, or omega-3, essential fatty acid. ALA is found in many seeds and oils, including flaxseed, walnuts, chia, hemp, and many common vegetable oils.

<span class="mw-page-title-main">Vegetable oil</span> Oil extracted from seeds or from other parts of plants

Vegetable oils, or vegetable fats, are oils extracted from seeds or from other parts of edible plants. Like animal fats, vegetable fats are mixtures of triglycerides. Soybean oil, grape seed oil, and cocoa butter are examples of seed oils, or fats from seeds. Olive oil, palm oil, and rice bran oil are examples of fats from other parts of plants. In common usage, vegetable oil may refer exclusively to vegetable fats which are liquid at room temperature. Vegetable oils are usually edible.

<span class="mw-page-title-main">Margarine</span> Semi-solid oily spread often used as a butter substitute

Margarine is a spread used for flavoring, baking, and cooking. It is most often used as a substitute for butter. Although originally made from animal fats, most margarine consumed today is made from vegetable oil. The spread was originally named oleomargarine from Latin for oleum and Greek margarite. The name was later shortened to margarine.

<span class="mw-page-title-main">Hydrogenation</span> Chemical reaction between molecular hydrogen and another compound or element

Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically constitutes the addition of pairs of hydrogen atoms to a molecule, often an alkene. Catalysts are required for the reaction to be usable; non-catalytic hydrogenation takes place only at very high temperatures. Hydrogenation reduces double and triple bonds in hydrocarbons.

<span class="mw-page-title-main">Coconut oil</span> Edible oil derived from coconut

Coconut oil is an edible oil derived from the kernels, meat, and milk of the coconut palm fruit. Coconut oil is a white solid fat below around 25 °C (77 °F), and a clear thin liquid oil in warmer climates. Unrefined varieties have a distinct coconut aroma. Coconut oil is used as a food oil, and in industrial applications for cosmetics and detergent production. The oil is rich in medium-chain fatty acids.

Trans fat regulation, that aims to limit the amount of "trans fat" — fat containing trans fatty acids — in industrial food products, has been enacted in many countries. These regulations were motivated by numerous studies that pointed to significant negative health effects of trans fat. It is generally accepted that trans fat in the diet is a contributing factor in several diseases, including cardiovascular disease, diabetes, and cancer.

A saturated fat is a type of fat in which the fatty acid chains have all single bonds between the carbon atoms. A fat known as a glyceride is made of two kinds of smaller molecules: a short glycerol backbone and fatty acids that each contain a long linear or branched chain of carbon (C) atoms. Along the chain, some carbon atoms are linked by single bonds (-C-C-) and others are linked by double bonds (-C=C-). A double bond along the carbon chain can react with a pair of hydrogen atoms to change into a single -C-C- bond, with each H atom now bonded to one of the two C atoms. Glyceride fats without any carbon chain double bonds are called saturated because they are "saturated with" hydrogen atoms, having no double bonds available to react with more hydrogen.

<span class="mw-page-title-main">Cottonseed oil</span> Cooking oil

Cottonseed oil is cooking oil from the seeds of cotton plants of various species, mainly Gossypium hirsutum and Gossypium herbaceum, that are grown for cotton fiber, animal feed, and oil.

<span class="mw-page-title-main">Shortening</span> Food ingredient

Shortening is any fat that is a solid at room temperature and is used to make crumbly pastry and other food products.

<span class="mw-page-title-main">Crisco</span> American shortening brand

Crisco is an American brand of shortening that is produced by B&G Foods. Introduced in June 1911 by Procter & Gamble, it was the first shortening to be made entirely of vegetable oil, originally cottonseed oil. Additional products marketed under the Crisco brand include a cooking spray, various olive oils, and other cooking oils, including canola, corn, peanut, sunflower, and blended oils.

<span class="mw-page-title-main">Wilhelm Normann</span> German chemist (1870–1939)

Wilhelm Normann was a German chemist who introduced the hydrogenation of fats in 1901. This invention, protected by German patent 141,029 in 1902, had a profound influence on the production of margarine and vegetable shortening.

<span class="mw-page-title-main">Soybean oil</span> Oil obtained from seeds of soya plant

Soybean oil is a vegetable oil extracted from the seeds of the soybean. It is one of the most widely consumed cooking oils and the second most consumed vegetable oil. As a drying oil, processed soybean oil is also used as a base for printing inks and oil paints.

<span class="mw-page-title-main">Polyunsaturated fat</span> Type of fatty acid defined by molecular bonds

In biochemistry and nutrition, a polyunsaturated fat is a fat that contains a polyunsaturated fatty acid, which is a subclass of fatty acid characterized by a backbone with two or more carbon–carbon double bonds. Some polyunsaturated fatty acids are essentials. Polyunsaturated fatty acids are precursors to and are derived from polyunsaturated fats, which include drying oils.

<span class="mw-page-title-main">Lard</span> Semi-solid white pork fat product

Lard is a semi-solid white fat product obtained by rendering the fatty tissue of a pig. It is distinguished from tallow, a similar product derived from fat of cattle or sheep.

In the food industry and biochemistry, interesterification (IE) is a process that rearranges the fatty acids of a fat product, typically a mixture of triglycerides. The process implies breaking and reforming the ester bonds C–O–C that connect the fatty acid chains to the glycerol hubs of the fat molecules. The reactions involve catalysts, either inorganic chemicals or enzymes.

<span class="mw-page-title-main">Cooking oil</span> Oil consumed by humans, of vegetable or animal origin

Cooking oil is a plant or animal liquid fat used in frying, baking, and other types of cooking. Oil allows higher cooking temperatures than water, making cooking faster and more flavorful, while likewise distributing heat, reducing burning and uneven cooking. It sometimes imparts its own flavor. Cooking oil is also used in food preparation and flavoring not involving heat, such as salad dressings and bread dips.

<span class="mw-page-title-main">Trans fat</span> Type of unsaturated fat

Trans fat, also called trans-unsaturated fatty acids, or trans fatty acids, is a type of unsaturated fat that occurs in foods. Trace concentrations of trans fats occur naturally, but large amounts are found in some processed foods. Since consumption of trans fats is unhealthy, artificial trans fats are highly regulated or banned in many nations. However, they are still widely consumed in developing nations, resulting in hundreds of thousands of deaths each year. The World Health Organization (WHO) had set a goal to make the world free from industrially produced trans fat by the end of 2023. The goal was not met, and the WHO announced another goal "for accelerated action till 2025 to complete this effort" along with associated support on 1 February 2024.

References

  1. ↑ Ian P. Freeman "Margarines and Shortenings" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. doi : 10.1002/14356007.a16_145
  2. 1 2 3 4 5 6 Teresa Tarrago-Trani, Maria; Phillips, Katherine M.; Lemar, Linda E.; Holden, Joanne M. (2006). "New and Existing Oils and Fats Used in Products with Reduced Trans-Fatty Acid Content" (PDF). Journal of the American Dietetic Association. 106 (6): 867–880. doi:10.1016/j.jada.2006.03.010. PMID   16720128.
  3. ↑ "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.
  4. ↑ "New York City passes trans fat ban". NBC News . 2006-12-05. Archived from the original on February 13, 2013. Retrieved 2010-01-09.
  5. ↑ "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.
  6. ↑ the American Heart Association,Sacks FM, Lichtenstein AH, Wu JH, Appel LJ, Creager MA, Kris-Etherton PM, Miller M, Rimm EB, Rudel LL, Robinson JG, Stone NJ, Van Horn LV (July 2017). "Dietary Fats and Cardiovascular Disease: A Presidential Advisory From the American Heart Association". Circulation. 136 (3): e1–e23. doi: 10.1161/CIR.0000000000000510 . PMID   28620111. 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.
  7. ↑ Nobel Lectures, Chemistry, 1901–1921. Elsevier. 1966. Reprinted online: "Paul Sabatier, The Nobel Prize in Chemistry 1912". Nobel Foundation. Retrieved 7 January 2007.
  8. ↑ de 141029 Process for converting unsaturated fatty acids or their glycerides into saturated compounds
  9. ↑ gb 190301515 Process for converting unsaturated fatty acids or their glycerides into saturated compounds
  10. ↑ Patterson HB (1998). "Hydrogenation" (PDF). Sci Lecture Papers Series. Archived from the original (PDF) on 26 September 2007. Retrieved 7 January 2007.
  11. 1 2 "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.
  12. ↑ Shurtleff W, Aoyagi A. "History of Soybeans and Soyfoods: 1100 B.C. to the 1980s". Archived from the original on 18 October 2005.
  13. ↑ Kummerow FA (2008). Cholesterol Won't Kill You – But Trans Fat Could. Trafford Publishing. ISBN   978-1-4251-3808-0. NOTE: Unreliable source.
  14. ↑ Ascherio A, Stampfer MJ, Willett WC (1999). "Trans fatty acids and coronary heart disease". The New England Journal of Medicine. 340 (25): 1994–8. doi:10.1056/NEJM199906243402511. PMID   10379026. Archived from the original on 3 September 2006. Retrieved 14 September 2006.
  15. ↑ "Ask the Experts: Hydrogenated Oils". Berkeley Wellness. Remedy Health Media. October 1, 2011. Retrieved 24 November 2018.
  16. ↑ Collette, Robert L. (July 7, 2015). "Why a Monograph for Fully Hydrogenated Oils and Fats is Needed". Quality Matters. United States Pharmacopeial Convention . Retrieved 24 November 2018.
  17. ↑ Haynes, Fiona (September 23, 2018). "Partially vs. Fully Hydrogenated Oils: The Truth About Trans Fats". The Spruce Eats. Dotdash . Retrieved 24 November 2018.
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