Margarine

In the meantime, margarine manufacturers had made many changes. Modern margarine can be made from any of a wide variety of animal or vegetable fats, and is often mixed with skimmed milk, salt, and emulsifiers. Margarine made from vegetable oils is especially important in today's market, as it provides a vegan and pareve substitute for butter. Nearly all margarine is salted, which makes shortening (which contains no salt) a better choice for baking.

In terms of microstructure, margarine is a water-in-oil emulsion, containing dispersed water droplets of typically 5-10 µm diameter. The amount of crystallizing fat in the continuous oil+fat phase determines the firmness of the product. In the relevant temperature range, saturated fats contribute most to the amount of crystalline fat, whereas monounsaturated and polyunsaturated fats contribute relatively little to the amount of crystalline fat in the product. Mono- and polyunsaturated fats and oils can be transformed into suitable substrates by the chemical process of hydrogenation, which renders them solid at room temperature. Full hydrogenation results in saturated fats only, but partial hydrogenation will lead to the formation of trans-fats as well.

Three main types of margarine are common:

• Hard, generally uncolored margarine for cooking or baking. (Shortening)
• "Traditional" margarines for such uses as spreading on toast, which contain saturated fats, are mostly made from vegetable oils.
• Margarines high in mono- or polyunsaturated fats, which are made from safflower, sunflower, soybean, cottonseed, rapeseed, or olive oil.

Many popular table spreads today are blends of margarine and butter — something that was long illegal in countries including the United States and Australia — and are designed to combine the lower cost and easy-spreading of artificial butter with the taste of the real thing.

Margarine, particularly polyunsaturated margarine, has become a major part of the Western diet. In the United States, for example, in 1930 the average person ate over 18 lb (8 kg) of butter a year and just over 2 lb (900g) of margarine. By the end of the 20th century, an average American ate just under 4 lb (1.8 kg) of butter and nearly 8 lb (3.6 kg) of margarine.

Under European Union directives, margarine products cannot be called "butter", even if most of it consists of natural butter. In some European countries butter based table spreads and margarine products are marketed as "butter mixtures".

These "butter mixtures" compose a significant portion of the table spread market. The brand "I Can't Believe It's Not Butter" spawned a variety of similarly-named spreads that can be found on supermarket shelves all over the world. With names like "Utterly Butterly," "You'd Butter Believe it," "Unbelievable! This Is Not Butter," and "Butterlicious," these butter mixtures avoid the restrictions on labeling with marketing techniques that imply a strong similarity to real butter.

The United States imports 10 billion pounds (4.5 million tons) of margarine a year. Additionally, the United States exports 2 billion pounds (900,000 tons) of margarine annually.

Margarine has a particular market to Orthodox Jews. The laws of Kashrut (the Jewish dietary laws) forbid the mixing of meat and dairy products, and hence there are strictly Kosher margarines available, which are often used by Jews adapting recipes that use meat and butter to be Kosher.

Nutrition

Discussions concerning the nutritional value of margarine revolve around two aspects — the total amount of fat, and the types of fat (saturated fat, trans fat). Usually, a comparison between margarine and butter is included in this context as well.

Amount of fat

Fat is an essential part of nutrition. It is needed in the production of cell membranes, as well as in several hormone-like compounds called eicosanoids. In addition, fat acts as carrier for fat-soluble vitamins A, D, E and K.^[7]

The total amount of fat eaten isn't really linked with any disease.^[8] The roles of butter and traditional margarine (80% fat) are similar with respect to their energy content, but low-fat margarines and spreads are widely available.

Saturated fat

The saturated fatty acids in triglycerides contribute to elevated blood cholesterol levels,^[9][10] which in turn has been linked to cardiovascular diseases. Saturated fat increases both LDL and HDL cholesterol.

Vegetable fats can contain anything between 7% and 86% saturated fatty acids. Liquid oils (unhardened canola oil, sunflower oil) tend to be on the low end, while tropical oils (coconut oil, palm kernel oil) and fully hardened oils are at the high end of the scale.^[11] A margarine blend is a mixture of both types of components, and will rarely exceed 50% saturated fatty acids on fat. Exceptions are some traditional kitchen margarines or products that have to maintain stability under tropical conditions.^[12] Generally, firmer margarines contain more saturated fat.

Regular butterfat contains about 65% saturated fatty acids on fat,^[13] although this varies somewhat with season. One tablespoon of butter contains over 7g of saturated fat.

Unsaturated fat

The unsaturated fatty acids decrease LDL cholesterol (the "bad" cholesterol) levels and increase HDL cholesterol (the "good" cholesterol) levels in the blood, thus reducing the risk of contracting cardiovascular diseases.^[14].^[15][16]

There are two types of unsaturated oils — mono- and polyunsaturated fats. Their nutritional and health effects are recognized in contrast to saturated fats. Some widely grown vegetable oils, such as rapeseed (and its variant canola), sunflower, safflower, and olive oils contain high amounts of unsaturated fats.^[11] During the manufacture of margarine, some of the unsaturated fats may be converted into saturated fats or trans fats in order to give them a higher melting point so that they are solid at room temperatures.

• Omega-3 fatty acids are a family of polyunsaturated fatty acids, which have been found especially good for health (see the main article). This is one of the two Essential fatty acids, so called because humans cannot manufacture it and must get it from food. Most modern Western diets are severely deficient in it. Omega-3 fatty acids are mostly obtained from oily fish caught in high-latitude waters. They are comparatively uncommon in vegetable sources. However, one type of Omega-3 fatty acid, alpha-lineloic acid (ALA) can be found in some vegetable oils. Flax oil contains 30-50% of ALA, and is becoming a popular dietary supplement to rival fish oils; both are often added to premium margarines. An ancient oil plant, camelina sativa, has recently gained popularity because of its high Omega-3 content (30-45%), and it has been added to some margarines. Hemp oil contains about 20% ALA. Small amounts of ALA are found in vegetable oils such as soybean oil (7%), rapeseed oil (7%) and wheat germ oil (5%).

• Omega-6 fatty acids are also important for health. They include the Essential Fatty Acid Linoleic Acid (LA), which is abundant in vegetable oils grown in temperate climates. Some, such as hemp (60%) and the common margarine oils corn (60%), cottonseed (50%) and sunflower (50%), have large amounts, but most temperate oil seeds have over 10% LA. Modern Western diets are frequently quite high in Omega-6 but very deficient in Omega-3. The Omega-6 to Omega-3 ratio is typically 10:1 to 30:1. Large amounts of Omega-6 decreases the effect of Omega-3. Therefore it is recommended that the ratio in the diet should be less than 4:1, although optimal ratio may be closer to 1:1.^[17][18]

Trans fat

Several large studies^{[19][20][21][22]} indicate a link between consumption of high amounts of trans fat and coronary heart disease, and possibly some other diseases. This is mainly because trans fats increase the amount of LDL cholesterol and decrease the amount of HDL cholesterol in blood stream. The United States Food and Drug Administration (FDA), the National Heart, Lung and Blood Institute and the American Heart Association (AHA) all have recommended people to limit intake of trans-fat.

Trans fats occur naturally in vegetable oils in only tiny quantities. However, they are a deliberate consequence of partial hydrogenation of light oils, intended to solidify the oil sufficiently for it to take on the eating quality of butter oil. In contrast, full hydrogenation generates few trans fats, but is intended to turn light oils into fully saturated fats. The intended effect of partial hydrogenation is to straighten the molecule of polyunsaturated fatty acids, so that they behave more like saturated fats. These trans fatty acids are used by the body like saturated fats, mainly as fuel, but tend to block the use of Omega-3 and Omega-6 for vital bodily functions. They have been indicted as worse for health than even the well-publicized saturated fats in butter and meat.^[23]

Particularly in the US, partial hydrogenation has been common as a result of national dependence on a limited number of vegetable oil sources, US-grown oils being preferred to tropical oils which are principally saturated fat. However, in other parts of the world, the industry started to move away from using partially hydrogenated oils in the mid-1990s.^[24] This led to the production of new margarine varieties that contain less or no trans fat.^[25] Many manufacturers in the US now label their products (following government regulations) as "zero grams" trans-fat, which effectively means less than 500 mg trans-fat per serving; however, no fat is entirely free of trans fats. For example, natural butterfat contains 2-5% trans-fatty acids (mainly trans-vaccenic acid, a variant of the normal vaccenic acid).^[26]

Cholesterol

Typically about 70% of human cholesterol is produced by the human body and only 30% comes from food sources. Thus intake of cholesterol as food has less effect on blood cholesterol levels than the type of fat eaten.^[8] However, some individuals are more responsive to dietary cholesterol than others. In the US, the FDA states that healthy people should not consume more than 300 mg of cholesterol each day.

Butter contains approximately 33 mg of cholesterol in each tablespoon.^[27] Margarine contains only negligible amounts of or no cholesterol.^[28]

Plant sterol/stanol esters

Plant sterol esters or plant stanol esters have been added to some margarines and spreads because of their cholesterol lowering effect. Several studies have indicated that consumption of about 2 grams per day provides a reduction in LDL cholesterol of about 10%.^[29][30] Sterol/stanol esters are tasteless and odorless, and have the same physical and chemical properties typical of most fats. However, they do not enter the blood stream but instead pass through the gut. Thus they suit well to be used in low-fat spreads.

References

1. ^ Science Power 9: Atlantic Edition, McGraw-Hill Ryerson Limited. ISBN 0-07-560905-3.
2. ^ Visser, Margaret (1986). Much Depends on Dinner. Toronto: Harper Perennial Canada. pp. 107. ISBN 0 00 639104 4.
3. ^ Intrastate sales of colored oleomargarine
4. ^ "Yellow margarine: I Can't Believe It's Not Legal!". AP / USA Today (2008-12-16).
5. ^ ^{a b} "Canada's conflicted relationship with margarine". CBC News Online (2005-03-18). Retrieved on 2007-08-28.
6. ^ "Resolving Canada's conflicted relationship with margarine". CBC News Online (2008-07-09). Retrieved on 2008-07-10.
7. ^ Mayo Clinic (January 31, 2007). "Dietary fats: Know which types to choose". Retrieved on 2008-05-18.
8. ^ ^{a b} Harvard School of Public Health. "The Nutrition Source - Fats and Cholesterol". Retrieved on 2008-05-18.
9. ^ A. Keys, J.T. Anderson, F. Grande, Serum cholesterol response to changes in the diet. IV. Particular fatty acids in the diet, Metabolism 14, 776-787 (1965).
10. ^ R.P. Mensink, P.L. Zock, A.D.M. Kester, M.B. Katan, Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: A meta-analysis of 60 controlled studies, American Journal of Clinical Nutrition 77, 1146-1155 (2003).
11. ^ ^{a b} NutriStrategy (2005). "Fats, Cooking Oils and Fatty Acids". Retrieved on 2008-05-18.
12. ^ D.W. de Bruijne, A. Bot, Fabricated Fat-based Foods, in: Food Texture — Measurement and Perception (editor A.J. Rosenthal), Aspen, Gaithersburg, 1999, pp. 185-227.
13. ^ http://www.nal.usda.gov/fnic/foodcomp/search/
14. ^ Müller et al. (January 2003). "The Serum LDL/HDL Cholesterol Ratio Is Influenced More Favorably by Exchanging Saturated with Unsaturated Fat Than by Reducing Saturated Fat in the Diet of Women". Retrieved on 2008-05-18.
15. ^ Hu, Manson, Willett (2001). "Types of Dietary Fat and Risk of Coronary Heart Disease: A Critical Review". Retrieved on 2008-05-18.
16. ^ Jeppesen et al. (2001). "Low Triglycerides–High High-Density Lipoprotein Cholesterol and Risk of Ischemic Heart Disease". Retrieved on 2008-05-18.
17. ^ Clear Springs Press (2006). "Omega-3 and Omega-6 Essential fatty Acids (EFA)". Retrieved on 2008-07-18.
18. ^ Chico College of Agriculture (January 18, 2007). "Grass Fed Beef - Health Benefits". Retrieved on 2008-07-18.
19. ^ W.C. Willett, M.J. Stampfer, J.E. Mason, G.A. Colditz, F.E. Speizer, B.A. Rosner, L.A. Sampson, C.H. Hennekes, Intake of trans fatty acids and risk of coronary heart disease among women, Lancet 341, 581-585 (1993)
20. ^ F.B. Hu, M.J. Stampfer, J.E. Manson, E. Rimm, G.A. Colditz, B.A. Rosner, C.H. Hennekens, W.C. Willett, Dietary Fat Intake and the Risk of Coronary Heart Disease in Women, New England Journal of Medicine 337, 1491-1499 (1997) http://content.nejm.org/cgi/content/short/337/21/1491
21. ^ K. Hayakawa, Y.Y. Linko, P. Linko, The role of trans fatty acids in human nutrition, Journal of Lipid Science and Technology 102, 419-425 (2000)
22. ^ The Nurses' Health Study (NHS)
23. ^ M. G. Enig, Trans-Fatty Acids in the Food Supply: a comprehensive report covering 60 years of research, Silver Spring, MD, Enig Associates, 1993.
24. ^ E. Flöter, G. van Duijn, Trans-free fats for use in foods, in: Modifying lipids for use in foods (editor F.D. Gunstone), Woodhead, Cambridge, UK, 2006, pp. 429-443.
25. ^ G. van Duijn, Technical aspects of trans reduction in modified fats, Oléagineux, Corps Gras, Lipides, 12, 422-426 (2005)
26. ^ See, e.g., P.S. Anand et al., J. Dairy Res. 71, 66-73 (2004)
27. ^ Cleveland Clinic. "Butter vs. Margarine". Retrieved on 2008-05-18.
28. ^ Jane Hurley, Bonnie Liebman (December 2001). "Better than Butter?". Retrieved on 2008-05-20.
29. ^ Katan et al. (2003). "Efficacy and Safety of Plant Stanols and Sterols in the Management of Blood Cholesterol Levels" (PDF). Retrieved on 2008-04-08.
30. ^ IFIC (July 2007). "Functional Foods Fact Sheet: Plant Stanols and Sterols". Retrieved on 2008-04-08.