There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.
You can buy this lab book for $23 at amazon.com or lulu.com. It will take 1-2 weeks to get to you -- Order Now. It’s a great resource, especially with the 2016-2017 science budget being used up!
*Some of you have already purchased my lab book – be sure to check out Page 141 !
“Margarine (aka oleomargarine) was first created in 1869 by a French chemist named Hippolyte Mège-Mouriès. It was originally made from beef fat and was intended to be a cheaper and less perishable option to regular butter. Over time, vegetable oils such as cottonseed and soybean oils replaced the animal fats, and by World War I margarine was almost exclusively made from these vegetable oils.”
“Some people worried that the new-fangled margarine was an unwholesome, adulterated food while others loved its lower price and longer shelf-life. Margarine became even more popular in the 1930s and 1940s during the Depression and World War II because of its cheaper price and a scarcity of butter, and it’s popularity really took off in the second half of the 20th century when it became the trend to shun traditional saturated fats (such as butter and lard) and to use vegetable oil-based products instead.”
“In the late 19th century, chemists discovered that they could add hydrogen atoms to unsaturated fats by bubbling hydrogen gas through vegetable oil in the presence of a nickel catalyst. (4) This was far more than a chemical curiosity. Partially hydrogenated oils don’t spoil as easily as nonhydrogenated fats. They can withstand repeated heating without breaking down. And the process can turn a liquid oil into a solid, which allowed for easier transportation and wider uses; this solid fat was also much less expensive than solid animal fats.
These characteristics were attractive to food makers. Over the last several decades, partially hydrogenated oils became a mainstay in margarines, commercially baked goods, and snack foods. When saturated fat was fingered as a contributor to high cholesterol, companies such as McDonald’s and Dunkin’ Donuts switched from beef tallow to partially hydrogenated vegetable oil for frying French fries and donuts.
At the time, switching from butter or lard (both of which contain high amounts of saturated fat) to a product made from healthy vegetable oil seemed to make sense. Intake of trans fat increased dramatically. Before the advent of partial hydrogenation, the only trans fat that humans consumed came from eating cows (or dairy products), lamb, and deer; in ruminants like these, bacteria living in the stomach make small amounts of trans fat. But due to the growth of partial hydrogenation, by the early 1990s, trans fat intake in the United States averaged 4 to 7 percent of calories from fat.
In 1981, a group of Welsh researchers speculated that trans fat might be linked with heart disease. (5) A 1993 Harvard study strongly supported the hypothesis that intake of partially hydrogenated vegetable oils contributed to the risk of having a heart attack. (3) In that study, the researchers estimated that replacing just 2 percent of energy from trans fat with healthy unsaturated fat would decrease the risk of coronary heart disease by about one-third. An influential symposium on trans fat later in the 1990s drew public attention to the issue.
Today we know that eating trans fats increases levels of low-density lipoprotein (LDL, “bad” cholesterol), especially the small, dense LDL particles that may be more damaging to arteries. It lowers levels of high-density lipoprotein (HDL) particles, which scour blood vessels for bad cholesterol and truck it to the liver for disposal. It also promotes inflammation, (6) an overactivity of the immune system that has been implicated in heart disease, stroke, diabetes, and other chronic conditions. Eating trans fat also reduces the normal healthy responsiveness of endothelial cells, the cells that line all of our blood vessels. In animal studies, eating trans fat also promotes obesity and resistance to insulin, the precursor to diabetes.
This multiple-pronged attack on blood vessels translates into heart disease and death. An analysis of the health effects of industrial trans fats conducted by researchers with the Harvard School of Public Health Department of Nutrition indicates that eliminating trans fats from the U.S. food supply could prevent up to 1 in 5 heart attacks and related deaths. That would mean a quarter of a million fewer heart attacks and related deaths each year in the United States alone. (7) (As noted above, trans fats do naturally occur in dairy foods and meat from ruminant animals, but trans fats from these sources do not make up as significant a part of the American diet, so they are not as much of a public health concern.)”
The previous article is very comprehensive; for further reading about partially hydrogenated fats (or “trans” fat), read the following:
“In 2013, [the] FDA [Food and Drug Administration] made a preliminary determination that PHOs [partially hydrogenated oils] were no longer "generally recognized as safe," or GRAS, for short. FDA is finalizing that action and determining that PHOs are not GRAS for any use in human food.
‘We made this determination based on the available scientific evidence and the findings of expert panels,’ says Susan Mayne, Ph.D., Director of FDA’s Center for Food Safety and Applied Nutrition. ‘Studies show that diet and nutrition play a key role in preventing chronic health problems, such as cardiovascular disease and today’s action goes hand in hand with other FDA initiatives to improve the health of Americans, including updating the Nutrition Facts label,’ she adds.
Trans fat wouldn't be completely gone, Mayne notes, because it also occurs naturally in meat and dairy products. It is also present at very low levels in other edible oils, where it is unavoidably produced during the manufacturing process. In addition, companies can petition FDA for specific uses of certain partially hydrogenated oils.”
“Early in the 20th century, trans fats were found mainly in solid margarines and vegetable shortening. As food makers learned new ways to use partially hydrogenated vegetable oils, they began appearing in everything from commercial cookies and pastries to fast-food French fries.
Eating foods rich in trans fats increases the amount of harmful LDL cholesterol in the bloodstream and reduces the amount of beneficial HDL cholesterol. Trans fats create inflammation, which is linked to heart disease, stroke, diabetes, and other chronic conditions. They contribute to insulin resistance, which increases the risk of developing type 2 diabetes. Research from the Harvard School of Public Health and elsewhere indicates that trans fats can harm health in even small amounts: for every 2% of calories from trans fat consumed daily, the risk of heart disease rises by 23%.
Trans fats have no known health benefits and that there is no safe level of consumption. Today, these mainly man-made fats are rapidly fading from the food supply.”
This is an interesting topic to cite during an Organic Chemistry unit. Also, reading these articles could be used as a Homework or Extra Credit assignment.
Past Organic Chemistry posts include:
05/28/2014 Organic Chemistry –
05/25/2014 Organic Chemistry –
05/21/2014 Organic Chemistry –
Alkanes, Alkenes & Alkynes
05/14/2015 Fractional Distillation
*This Blog contains several entries that would be helpful to your chemistry classroom. Check out the Topic List to help you to find past Blog entries.
Also, Write To Me about your successes, challenges, or questions in the Chemistry Classroom.
Remember, buying a copy of the lab book Chemistry on a Budget can be very useful to your Chemistry classroom with labs and class article ideas.
Have a great weekend!