polyunsaturated fat is an abbreviation of polyunsaturated fatty acid. That is a fatty acid in which more than one double bond exists within the representative molecule. That is, the molecule has two or more points on its structure capable of supporting hydrogen atoms not currently part of the structure. Polyunsaturated fatty acids can assume a cis or trans conformation depending on the geometry of the double bond

Answered by pankaj , an ibibo Advisor, at 12:14 PM on September 20, 2008

What "saturated" fats are saturated with is hydrogen atoms. "Unsaturated" fats do not have hydrogen atoms at every available bonding site on the molecule. Polyunsaturated fats have more than one of these bonds which lack hydrogen. Oils with primarily polyunsaturated fats are liquid even in the refrigerator. The two main types of polyunsaturated fats are omega-3 fats and omega-6 fats, which are essential fatty acids, meaning the body cannot manufacture them.

Although polyunsaturated fats are generally thought of as healthy, there are at least two possible exceptions to this statement. One is that there is some evidence that polyunsaturated fat, in excess, can contribute to cancer risk. It is thought that the reason for this may be that polyunsaturated fats turn rancid more quickly than other fats. Therefore, proper storage of oils with high amounts of polyunsaturated fats is recommended. Store in a cool, dark place before opening, and in the refrigerator after opening.

The other potential issue with polyunsaturated fats is that of the two main types of polyunsaturated fat, the amount of omega-6 fat that we tend to consume has increased dramatically in recent decades, while in general the amount of omega-3 fat we consume is lower. Some experts feel that this imbalance is contributing to inflammation in our bodies, and increasing the risk of such chronic diseases as arthritis, diabetes, and heart disease.

Examples: Oils high in polyunsaturated oil include corn oil, soy oil, regular safflower and sunflower oils (i.e., not "high oleic" oil), and cottonseed oil. Flax seed oil is high in omega-3 fats.

Answered by Yogeshwar , an ibibo Specialist, at 8:04 PM on September 19, 2008

Well Rinku,

Polyunsaturated fats are extremely vulnerable to damage from heat, so they are not suitable for high-temperature cooking. These oils are best used in salad dressings, sauces, and dips. To add flavor to grains and stir-fry dishes, sprinkle the cooked food with flaxseed oil just before serving.
Buying and storing tips

Polyunsaturated oils can become rancid when exposed to heat, light, and oxygen. As a result, oil-processing methods affect the nutritional content, storage life, and quality of oils. Choosing a high quality cooking oil can be a challenge unless one understands the terms that food manufacturers use to describe the methods by which cooking oils are processed. When purchasing cooking oil, it is important to review the label, and note the method of extraction, and whether the oil is refined or unrefined. Whenever possible, choose expeller-pressed, unrefined oils (see definitions below). Select oils in light-resistant plastic containers, or dark brown or green glass containers

Source : http://www.vitacost.com/Healthnotes /Food-Guide/Polyunsaturated-Fats.as px

Answered by Priyanka C , an ibibo Master, at 2:23 PM on September 19, 2008

well, Some fats are good because they can improve blood cholesterol levels.

Unsaturated Fats--Polyunsaturated and Monounsaturated

Unsaturated fats are found in products derived from plant sources, such as vegetable oils, nuts, and seeds. There are two main categories: polyunsaturated fats (which are found in high concentrations in sunflower, corn, and soybean oils) and monounsaturated fats (which are found in high concentrations in canola, peanut, and olive oils). In studies in which polyunsaturated and monounsaturated fats were eaten in place of carbohydrates, these good fats decreased LDL levels and increased HDL levels.

For mroe: http://www.gffi-fitness.org/Ar t_17.htm

Answered by Satya ~ , an ibibo Master, at 9:16 AM on September 19, 2008

What saturated fats are saturated with is hydrogen atoms. Unsaturated fats do not have hydrogen atoms at every available bonding site on the molecule. Polyunsaturated fats have more than one of these bonds which lack hydrogen. Oils with primarily polyunsaturated fats are liquid even in the refrigerator. The two main types of polyunsaturated fats are omega-3 fats and omega-6 fats, which are essential fatty acids, meaning the body cannot manufacture them.
Although polyunsaturated fats are generally thought of as healthy, there are at least two possible exceptions to this statement. One is that there is some evidence that polyunsaturated fat, in excess, can contribute to cancer risk. It is thought that the reason for this may be that polyunsaturated fats turn rancid more quickly than other fat.

Polyunsaturated fats can lower the level of bad cholesterol, low density lipoprotein (LDL). It contains essential fatty acids (EFAs) such as omega-6s (linoleic acid) and omega-3s (alpha-linoleic acid) that are needed in our diet. So, a certain amount of polyunsaturated fats are needed because essential fatty acids may help in prevent or control of all kinds of ailments and conditions such as:

•Heart disease,•Cancer ,•Immune system deficiencies ,•Arthritis and obesity.
Polyunsaturated fats are also one of few rich sources of vitamin E.

SOURCE SITE :http://www.thefoodchart.com/p olyunsaturated-fat.php

Answered by Sanya Tahir , an ibibo Master, at 9:22 PM on September 18, 2008

From a chemical standpoint, polyunsaturated fats are simply fats that have more than one double-bonded (unsaturated) carbon in the molecule. Polyunsaturated fats are typically liquid at room temperature and when chilled.
visit http://www.americanheart.or

Answered by Jyothi , an ibibo Master, at 7:12 PM on September 18, 2008

Polyunsaturated fats contain large amounts of polyunsaturated fatty acids (PUFAs). Polyunsaturated fatty acids are so-named because, due to the presence of two or more double bonds, there are places along the carbon chain where the fatty acid is not “saturated” with hydrogen. Polyunsaturated fats are liquid at room temperature, and remain in liquid form even when refrigerated or frozen. Polyunsaturated fats are divided into two families: the omega-3 fats and the omega-6 fats.
Source: http://www.mothernature.com/Li brary/Ency/Index.cfm/Id/188300 0

Answered by Vinay Kiran , an ibibo Specialist, at 5:44 PM on September 18, 2008

well,From a chemical standpoint, polyunsaturated fats are simply fats that have more than one double-bonded (unsaturated) carbon in the molecule. Polyunsaturated fats are typically liquid at room temperature and when chilled.

Answered by Debashis , an ibibo Master, at 5:39 PM on September 18, 2008

fats are energy giving compounds formed from "c"carbon,"h"hydrogen,"o" oxygen ..
they are formed by forming bonds between them like c-o,c=o.. o-h,
c-h... of these c=o is an unsaturated bond..
polyunsaturated fatty acids have such bonds in large number {poly=many}

Answered by Alok Rathi , an ibibo Citizen, at 5:29 PM on September 18, 2008

WELL THEY ARE OILS & FAITS WHICH ARE MADE OF LONG CHAIN FATTY ACIDS WHICH CONTAIN MORE THAN ONE DOUBLE BOND . THESE FATS ARE GENERALLY LIQUID AT ROOM TEMPERATURE . IF HYDROGEN IS ADDED THAN THE DOUBLE BONDS GET SATURATED & HYDROGENATED FAT IS MADE EG VANASPATI GHEE

Answered by Moksha G , an ibibo Master, at 5:20 PM on September 18, 2008