Trans Fats

Trans fats are certainly in the news lately… the Ontario Government and several other jurisdfictions propose to eliminate them from foods sold or served to students, fast food companies are falling over themselves to remove them from their products, and the editorial column in the Recorder and Times on Friday December 7 reviewed the health implications of trans fats, especially as they apply to children.

Let’s take a look at these fats and understand their chemistry and their effects upon our bodies. Trans fats (we’ll call them TF from here on) occur naturally in small quantities in the flesh and milk of most cattle. Our varied diet can deal with these amounts, but we have added massively to the amounts we ingest by figuring out how to make TFs. If you recall my column on fats a few weeks ago, I mentioned the hydrogenation process, discovered about 100 years ago. Using high pressures and catalysts, chemists added hydrogen atoms to the fat molecules. This process converted liquid oils, which were hard to store and spoiled readily, into solids that did not require refrigeration, had a long shelf life, and melted about body temperature or slightly above. This made them very useful in cooking, baking, and frying. Typical oils that were hydrogenated were cottonseed oil, whale oil, and palm oil. Crisco was one of the first manufactured fats to be marketed. Not all hydrogenated fats are TFs, but a large proportion can be, depending on the starting product and the hydrogenation process.

Remember how a fat molecule looks like a capital E, with three long chains attached to a three-carbon backbone. Trans fats are called trans because of the shape the molecule becomes after it is hydrogenated. Think of a chaise with the footrest down… that is what a TF molecule looks like: a capital E with three kinked legs.

Now let’s look at what TFs do in your body. Everyone has heard of cholesterol, and how its level in the blood is a health area to watch. There are two kinds of cholesterol, LDL (known as “bad”) and HDL (known as “good”). The acronyms denote low density lipid and high density lipid, if you were wondering. A key health indicator is the ratio of HDL to LDL. TFs cause an increase in the LDL and a decrease in the HDL, and therefore negatively affect the balance of the two kinds of cholesterol. Decades of research has concluded that high levels of LDL in the body dramatically increase the risks of heart attacks and strokes, and may have an effect on the development of diabetes, all of which can be life-threatening. Right now there is no proven link between TFs and cancer, but studies are on-going and more research is required.

Where are TFs found? Practically everywhere, especially if you eat a lot of fast and prepared foods. These include crackers, cookies, donuts, pastries, muffins, and croissants, snack foods and fried foods such as French fries and breaded foods. The TF content of these foods may be as high as 45% of the fat. Obviously if you do a lot of your own cooking and baking you can control the TF content better, but that is becoming less common in our fast-paced world. Our Canadian labeling requirements make it easier to determine the TF content of the foods you buy… read the label carefully and you will see that it specifically mentions TFs. This allows you to make better choices.

What is being done? There has been a groundswell of opinion against some of the large fast food companies urging them to voluntarily lower the TF in their products. Compliance has been slow but steady. Most of the fast food companies are indeed moving to lower or eliminate TFs from their products, sometimes after being nudged by legislation, but this is not as simple as it sounds. Some companies claim that their products do not taste the same when made with non-TFs, and as well, they are permitted to claim their product is free of TFs when it actually contains 0.2 grams per serving in Canada and 0.5 grams per serving in the US. Sometimes the typical serving is set very low, and none of us would limit ourselves to, say, one teaspoon, or five chips. Some food manufacturers claim that their product is TF-free, when it never contained TF in the first place. Many jurisdictions are bringing legislation forward to lower or eliminate TFs, especially in foods that appeal to children and teenagers, as the Ontario Government is now doing.

Some may argue that this is an example of the nanny-state philosophy carried too far, but there is no denying the huge costs to the health care system, and that means all of us, in caring for people suffering from the effects of TFs.
As a consumer you can help yourself by checking labels, lowering or eliminating the TF in your diet where possible, and, as I have mentioned before, including plenty of fruits and vegetables, which are definitely TF-free, in your diet.

Ethanol - the Basics

There are many complicated issues facing the public these days, ranging from waste disposal, recycling, air and water emissions, energy generation and consumption, transportation, and many others. These issues have at their core some elements of science, whether it is chemistry, physics, biology, engineering, statistics, or some combination of these. With your help, I would like to explore some of these issues and examine the science in more detail and together we can understand what is going on, what we are being told, whether it makes scientific sense, and perhaps make a slightly better judgement about the issue. I hope to use my contacts and experience in the scientific community to assist you, the readers, in understanding these issues. I welcome your input.Our area (Eastern Ontario) is about to benefit from the construction and operation of an ethanol plant, and I thought it might be appropriate to look at some of the chemistry of ethanol and try to understand what it is, what it does (as a fuel additive) and what are the pros and cons.Most of us are familiar with ethanol in the form of alcoholic beverages: wine, beer and distilled spirits. It is suggested that the manufacture of alcoholic beverages counts as the first chemical industry, dating back thousands of years. The ethanol we drink is diluted, with water, fruit extracts and flavourings, to about 5% in beer, about 12% in wine, and about 40% in distilled spirits.Ethanol, or ethyl alcohol as it is known in chemistry, is a clear colourless flammable liquid, completely miscible (mixes with) water in all proportions. It is the second in a chain of alcohols, because of the two carbon atoms, the first being methanol. The chemical formula is C2H5OH, with the OH group giving the characteristics of an alcohol.The first and still most important way of making ethanol is via fermentation of sugar or starch. Grapes were among the first fruits to be fermented because grapes are naturally sweet, the enzyme that produces ethanol is found on grape skins, and ethanol production is very simple, and takes place at room temperature, especially if your room is in the Mediterranean basin. Many fruits, vegetables and grains have been fermented in pretty much the same way to arrive at ethanol with many flavours, but the basic chemistry remains the same.When you are making beer and wine, you allow the fermentation to proceed to a specific point then you stop it chemically, filter or decant your product, and depending on your patience, let it mellow a little before drinking. Because the enzymes that do the work are killed off when the ethanol concentration is above about 15%, no wine or beer is naturally stronger than this.If you are making spirits (such as rum, rye, vodka etc.) or industrial ethanol, you must distil your mixture. Because ethanol boils at a lower temperature than water, if the fermentation mixture is heated above the boiling point of ethanol (78°C) but below 100°C the ethanol will boil and can be captured by cooling the vapour, giving pure ethanol. So, our plant in Johnstown will be taking corn, the same corn we feed to cattle and other animals, and fermenting it, then distilling it on a large scale.Here is what is happening, shown another way:C6H12O6 à 2 CO2 + 2 C2H5OHglucose carbon dioxide ethanolThis is how we show a reaction in chemistry, and it isn’t really complicated. Glucose is the simplest sugar. What is really interesting is that for every kilogram of ethanol produced, we get, free and for nothing, 0.95 kilograms of carbon dioxide. So far, no-one has said anything about the carbon dioxide by-product of fermentation.Another issue with ethanol is this: Right now all the fermentation technology relies on acting on the fruit or the seed grain portion of the plant material, because that is where the sugar or starch is concentrated. As anyone who has shucked corn knows, there is a pile of the corn plant that is wasted. If we can figure our how to convert that waste material, mostly cellulose, into ethanol, we will have some real progress. Thankfully, an Ottawa company called IOGEN has developed a process to do exactly that, and when it is commercialised (it is currently in the pilot-plant stage) then ethanol may become a significant player in the alternate fuel debate.As we currently stand, the energy balance, that is, the amount of energy you have to put into making ethanol vs. the amount of energy you get out is subject to considerable controversy. We will take a look at this later.Now, ethanol may have significant benefits with respect to automotive emissions, and reducing our reliance on fossil fuels, but as you can see it certainly doesn’t get us off the hook with respect to carbon dioxide, one of the main greenhouse gases.Next week (?) we will take a look at what ethanol does when it is mixed with gasoline and diesel fuel.
Posted by Rod at 6:37 PM 0 comments