Margarine is a spreadable vegetable fat that has been developed to serve as an alternative for butter. It has a similar taste to the animal product and can replace it in almost any recipe. It is usually found as either a spread with a soft texture or as sticks similar to butter. It is widely available in almost any store and usually much cheaper than real butter. Margarine has become increasingly important all around the world, especially since vegetable fats were thought to be much healthier than the ones of animal origin, which suddenly made margarine very popular.
The product was created by a Frenchman, Hippolyte Mège-Mouriès. He prepared it for the first time in 1869 but didn't initially name it margarine. He developed it at the request of Napoleon III, since the emperor wanted a cheap butter alternative for the poorer citizens and the armed forces.
Margarine is produced from a mixture of water and refined vegetable oils, although some milk might also be included. Butter is exclusively prepared from milk fat. It is also known as oleomargarine, or under the popular name "oleo" in some areas of the USA.
The structure of margarine is an emulsion of water in fat, where small drops of water are mixed with fats in crystalline form, similar to the one of butter. The percentage of fat in margarine is variable but in some countries it must be at least 80% fat, just like normal butter.
Margarine can be consumed in many ways, it is a versatile food that replaces butter in most recipes. It is commonly spread on bread or used as a baking ingredient for doughnuts, pastries or cookies.
Spreadable margarine is a very popular breakfast food, where it is added to many products such as toast bread, English muffin, bagels or biscuits. One of the most common uses is as a topping in melted form for fresh popcorn. When melted, it is also added on green cooked vegetables or baked potatoes. It is used as a cooking ingredient in many recipes, especially desserts like cakes, casseroles or pie crusts.
Several types of vegetable oils can serve as raw material for margarine and a combination is generally used. The most popular are corn oil and soybean oil, which are favoured by most producers. It all starts with the hydrogenation of the oil and then more hydrogen is added to the mix. This addition allows margarine to become solid and resemble the texture of real butter. Margarine is easier spreadable than butter, especially after refrigeration, because the oils in its composition are less affected by low temperatures. Since it contains no animal fats and the overall fat content tends to be lower, margarine was considered for a very long time to be a healthier alternative for butter.
However, some of the unsaturated fats present in the vegetable oils turn into saturated fats during the process of hydrogenation, which are dangerous for health. Producers have responded by lowering the percentage of these saturated fats in the composition, in order to adapt to the requirements of a modern healthy diet. Some of the brands that can be found in stores today claim to be a healthy choice, with fewer than 50% of the normal amount of saturated fats found in margarine.
The modern production method of margarine is to start with a mixture of fats and vegetable oils, and then emulsify it. Skimmed milk is sometimes added to the mix, which goes through hydrogenation, fractionation or interesterification. The final step is to achieve a texture similar to butter by cooling the mixture in order to make it solid. While fats of animal and vegetal origin are quite similar, their melting points are different and depend on the structure of the fatty acids components and whether carbon-carbon double bonds are present. The melting point becomes lower if the number of such bonds is higher. A fat is considered to be oil if it is liquid at normal temperatures.
The industrial process to hydrogenate natural oil is to inject oxygen into it, in special conditions, using nickel as a reaction catalyst. Alkenic double C=C bonds, also known as unsaturated bonds, become saturated in the presence of hydrogen.
As a result, the structure of the fat becomes harder, as the melting point increases and it turns solid. The scientific explanation for this behaviour is complex and related to the saturated molecules having stronger van der Waals' forces compared to the unsaturated ones. The process needs to be precisely controlled, since saturated fats are dangerous for human health. In order to counter this, their amount must be limited to the minimum required for a proper structure and texture of the product.
There is no way to avoid the presence of hydrogenated fats in margarine produced in this traditional method. It is still used today but new techniques have also been developed. It is possible to alter the process by using palladium and other metal catalysts instead of nickel. A downside of the classic hydrogenation procedure is the presence of trans-fats in margarine. These molecules are considered to be very dangerous for heart health. The high temperature required for hydrogenation turns some of the molecules with carbon-carbon double bonds into trans-fats, due to the so-called partial hardening, which is an unfinished hydrogenation process. Modern margarine production tries to reduce the amount of trans-fats as much as possible, in order to make it a healthier food item. This can be achieved by avoiding hydrogenation completely, using palm oil, coconut oil and other vegetal oils with a tropical origin. These are already in a partial solid state naturally.
Numerous types of fats, of both animal and vegetal origin, can be used to produce margarine. Salt, skimmed milk and emulsifier agents are usually added to the mix. The final amount of fats in the final product is variable, from as low as 10% to as high as 90%. The amount of fats and water depends on the purpose of the margarine, since it can be used to cooking, baking or as a spread. Vegetable oils are produced by pressing the raw seeds and then refining the liquid. Solid fats are then added to change the texture, or a hydrogenation process can be required to make the oils solid. Various ingredients are added to the mix, these include skimmed milk powder, water, citric acid and nutrients such as vitamins or carotenoids. Preservatives are required to increase the shelf life of margarine, while lecithin and other emulsifiers make sure that water is evenly distributed in the oil mix. The final step is to heat up the composition in order to blend the ingredients, and then cool it back. Products with a softer texture tend to be healthier than block margarine, since they contain less hydrogenated fats.
There are many types of margarine but three types are the most common. Spreadable products are popular for breakfast and they have a high content of mono- or polyunsaturated fats, which give them a soft texture. They are usually produced from sunflower, safflower, rapeseed, olive, soybean or cottonseed oils. Hard blocks of margarine are considered less healthy are tend to be colorless, since they are used for baking or cooking purposes. Finally, some products are available in a bottle and are used as toppings in various dishes.
Since margarine is marketed as a butter substitute, it usually has the same fat content of about 80%. It consists of a variable combination of saturated and unsaturated fats. The actual percentages depend on the raw material. Margarine made from tropical oils such as palm kernel oil or coconut oil has more saturated fats than products made from canola or sunflower oil. The percentage of saturated fats can be between 7 and 86%, with nutrients such as vitamins A, D, E and K.
Another bioactive compounds found in margarine is an omega-3 fatty acid named ALA (alpha-lineolic acid). It is beneficial for human health because it has an anti-inflammatory effect and reduces the levels of triglycerides and cholesterol. It is possible to increase the amount of healthy omega-3 fatty acids in margarine by adding fish oil or flax seed oil to the mix. Many commercial margarine brands also have plant sterol in their composition. This is added to make them healthier, since it is known to reduce blood cholesterol.
Some of the fats in margarine become saturated in the industrial process of hydrogenation, or turn into trans-fats. These are considered to be especially unhealthy, since they increase the risk of heart conditions, cancer and other chronic diseases. The main problem caused by trans-fats is the reduced intake of good cholesterol (HDL) and increased level of bad one (LDL).