Nutrition - Lipids (fats and oils) | sexygf.info
Fats and oils are the most abundant lipids in nature. They provide energy for living organisms, insulate body organs, and transport fat-soluble. This project focuses on saturated and unsaturated lipids (fats and oils). Eight test tubes, small graduate cylinder, Tincture of iodine, vegetable oil, distilled water, . Fats and oils are then discussed in relation to relevant disease categories. Finally, many fats are prone to lipid oxidation, which leads to the formation of off- flavors and The terms fat, oil and lipid are often used interchangeably by food scientists. .. For this reason, a number of accelerated oxidation tests have been .
The characteristic colors, odors, and flavors that we associate with some of them are imparted by foreign substances that are lipid soluble and have been absorbed by these lipids.
For example, the yellow color of butter is due to the presence of the pigment carotene; the taste of butter comes from two compounds—diacetyl and 3-hydroxybutanone—produced by bacteria in the ripening cream from which the butter is made. Fats and oils are lighter than water, having densities of about 0.
They are poor conductors of heat and electricity and therefore serve as excellent insulators for the body, slowing the loss of heat through the skin. Chemical Reactions of Fats and Oils Fats and oils can participate in a variety of chemical reactions—for example, because triglycerides are esters, they can be hydrolyzed in the presence of an acid, a base, or specific enzymes known as lipases.
The hydrolysis of fats and oils in the presence of a base is used to make soap and is called saponification. Sodium carbonate or sodium hydroxide is then used to convert the fatty acids to their sodium salts soap molecules: Soaps Ordinary soap is a mixture of the sodium salts of various fatty acids, produced in one of the oldest organic syntheses practiced by humans second only to the fermentation of sugars to produce ethyl alcohol.
Even so, the widespread production of soap did not begin until the s.
Soap was traditionally made by treating molten lard or tallow with a slight excess of alkali in large open vats. The mixture was heated, and steam was bubbled through it.
After saponification was completed, the soap was precipitated from the mixture by the addition of sodium chloride NaClremoved by filtration, and washed several times with water.
Good and Bad Lipids | Science project | sexygf.info
It was then dissolved in water and reprecipitated by the addition of more NaCl. The glycerol produced in the reaction was also recovered from the aqueous wash solutions. Pumice or sand is added to produce scouring soap, while ingredients such as perfumes or dyes are added to produce fragrant, colored soaps. Blowing air through molten soap produces a floating soap.
Soft soaps, made with potassium salts, are more expensive but produce a finer lather and are more soluble. They are used in liquid soaps, shampoos, and shaving creams. Dirt and grime usually adhere to skin, clothing, and other surfaces by combining with body oils, cooking fats, lubricating greases, and similar substances that act like glues. Because these substances are not miscible in water, washing with water alone does little to remove them.
Soap removes them, however, because soap molecules have a dual nature. One end, called the head, carries an ionic charge a carboxylate anion and therefore dissolves in water; the other end, the tail, has a hydrocarbon structure and dissolves in oils. The hydrocarbon tails dissolve in the soil; the ionic heads remain in the aqueous phase, and the soap breaks the oil into tiny soap-enclosed droplets called micelles, which disperse throughout the solution.
The droplets repel each other because of their charged surfaces and do not coalesce. The double bonds in fats and oils can undergo hydrogenation and also oxidation. The hydrogenation of vegetable oils to produce semisolid fats is an important process in the food industry.
17.2: Fats and Oils
Chemically, it is essentially identical to the catalytic hydrogenation reaction described for alkenes. In commercial processes, the number of double bonds that are hydrogenated is carefully controlled to produce fats with the desired consistency soft and pliable. Inexpensive and abundant vegetable oils canola, corn, soybean are thus transformed into margarine and cooking fats.Lipids - II : Oils and Fats
In the preparation of margarine, for example, partially hydrogenated oils are mixed with water, salt, and nonfat dry milk, along with flavoring agents, coloring agents, and vitamins A and D, which are added to approximate the look, taste, and nutrition of butter.
Preservatives and antioxidants are also added. In most commercial peanut butter, the peanut oil has been partially hydrogenated to prevent it from separating out.
Fats and Other Lipids - Diet and Health - NCBI Bookshelf
Consumers could decrease the amount of saturated fat in their diet by using the original unprocessed oils on their foods, but most people would rather spread margarine on their toast than pour oil on it. Many people have switched from butter to margarine or vegetable shortening because of concerns that saturated animal fats can raise blood cholesterol levels and result in clogged arteries.
- Trends in the Food Supply
- Interdependency of nutritional requirements
However, during the hydrogenation of vegetable oils, an isomerization reaction occurs that produces the trans fatty acids mentioned in the opening essay. Thank you for your input.
Material Availability The materials required for this project are readily available and inexpensive. Approximate Time Required to Complete the Project 1 to 2 hours to complete the activity once the materials are secured and setup. Also between 1 and 2 hours to prepare the Tri-fold board display. This project focuses on saturated and unsaturated lipids fats and oils. Diets high in saturated fat are linked to high blood cholesterol levels and heart decease.
High-fat diets can also increase the risk for obesity and cancer. The research aspect of this science fair project is to use a simple iodine test to determine if several common lipid products are saturated or unsaturated. The young investigator will test if a lipid is saturated or unsaturated by adding iodine to various substances. If the iodine changes from brown to clear the lipid is unsaturated.
If the iodine does not change colors the lipid is saturated. From the observations made data tables will be generated and the results displayed in the form of a graph. The practical application from the results of this project is to reinforce the idea that as part of a healthy diet we should try to reduce the amount of saturated lipids and trans-fats we eat and replace them with unsaturated lipids.
Eight test tubes, small graduate cylinder, Tincture of iodine, vegetable oil, distilled water, butter, margarine, fish oil, olive oil, corn oil, and sunflower oil. The oils, butter, margarine, and distilled water can be purchased from the local supermarket.
Fats and oils
Tincture of iodine is available from any drug store or the pharmacy department of most major retail Wal-Mart, Target, etc stores. Test tubes and a small graduate cylinder may be borrowed from a high school or college chemistry teacher, found in toy chemistry sets, or purchased from a hobby shop. Fats, oils and waxes belong to a group of compounds called lipids.