In the April 2006 issue of ChemMatters, I found an article entitled "Bread-and-butter issues, the chemistry of margarine" which is of great relevance to what I have just studied in the topic of organic chemistry. The author of this article is Andrew Parsons, who is currently a senior lecturer in the Department of Chemistry, University of York. This article mainly discusses the role of chemistry in the formation of margarine and how several chemical compounds such as addictives contribute to its taste.
What is margarine in this case? In chemistry terms, margarine is no more than a water-in-oil emulsion. There are mainly three types of margarine: Firstly, the hard, uncoloured margarine for cooking or baking, which contains a high proportion of animal fat. Secondly, the "Traditional" margarines use for spreading on toast, which contain a relatively high percentage of saturated fats and are made from either animal or vegetable oils.
Lastly, the margarines high in mono- or poly-unsaturated fats, which are made from safflower, sunflower, soybean, cottonseed, or olive oil, and which are said to be healthier than butter or other types of margarine. If margarine is said to be an emulsion, aren't it suppose to appear as two separate layers instead? However, here comes the magic of chemistry which I have just discovered as well! The oils and the water in margarine are in fact held together and stopped from separating by a supporting structure of solid fats and emulsifiers.
So how exactly does an emulsifier work? An emulsifier has a hydrophilic part that is attracted to water and a hydrophobic part that is attracted to oil. This makes it soluble in both the oil and the water phases. This works with the same principle as a surfactant which has a long hydrocarbon tail that is soluble in the...