Structure and classification of fats& oils

fats and oils are important part of our daily life.

1. STRUCTURE and classification of fats& oils DENNIS VARGHESE B.Voc (Food processing & Nutraceuticals ) 2 nd year, 3 rd sem pims

2. INTRODUCTION  Fats, are known as triglycerides, are esters of three fatty acid chains and the  alcohol  glycerol. The terms "lipid", "oil" and "fat" are often confused. "Lipid" is the general term, though a lipid is not necessarily a triglyceride. "Oil" normally refers to a lipid with short or unsaturated fatty acid chains that is liquid at room temperature An  oil  is any non polar chemical substance that is a viscous liquid at ambient temperatures and is both hydrophobic  and  lipophilic  . Oils have a high carbon and hydrogen content and are usually flammable and surface active.

3. CLASSIFICATION Fats are classified into saturated and unsaturated fats. The classification is important to enable you to advise your community about which fats can be consumed with less risk to people’s health. Saturated fats are not good for a person’s health. As a general rule, plant sources of fats are better for a person’s health than the animal sources, because animal fats contain more saturated fats.

4. Saturated fats  are usually solid at cool temperatures. Eating too much saturated fat is not good for a person’s health, as it can cause heart and blood vessel problems. Unsaturated fats  are usually liquid at room temperature. These types of fats are healthy fats. Examples include fats from fish, oil seeds (sesame and sunflower), maize oil and ground nut oil and breastmilk

5. Unsaturated Fats There are three types of unsaturated fatty acids:- Monounsaturated Fatty Acids (MUFA) Fatty acids in this category have what is known as one double bond in their chemical make-up. They are relatively stable to oxidation and the development of rancidity and are now considered, in nutritional terms, as being the best type of fat to eat. The most common source of monounsaturates are Olive Oil and Rapeseed oils.

6. Polyunsaturated Fatty Acids (PUFA) Polyunsaturated fatty acids contain two or more double bonds in their chemical make-up. They are least stable fatty acids to oxidation and as such are best used in cold applications. The most common source of polyunsaturates is Sunflowerseed oil

7. Trans Fatty Acids (TFA ) Trans fatty acids typically come from two sources, hydrogenated vegetable oils and animal fats. Recent scientific research suggests trans fats, although consumed in relatively small proportions, should be avoided due to their negative affect on blood cholesterol levels

8. Saturated Fats Certain fatty acids are already 'naturally saturated' in that they cannot be made 'harder' than they are in nature. As previously noted, the levels of saturates is generally higher in those fats which are solid at ambient temperatures. Saturated fatty acids are extremely stable i.e. they do not easily become rancid, meaning they have good keeping properties (shelf life).

9. However, Government recommendations advise consumers to limit their intake of saturated fats as they can increase blood cholesterol levels, one of the major factors in heart disease

10. VEGETABLE OILS With some exceptions, and in contrast to animal fats, vegetable oils contain predominantly unsaturated (light, liquid) fatty acids of two kinds: monounsaturated (oleic acid - mainly in extra virgin olive oil) and polyunsaturated ( linoleic acid and linolenic acid - in oils extracted from oilseeds).  Industrial and non-food uses of vegetable oils include the production of soaps, detergents, fatty acids, paint, varnish, resin, plastic and lubricants

11. Crude vegetable oils are obtained without further processing other than degumming or filtering. To make them suitable for human consumption, most edible vegetable oils are refined to remove impurities and toxic substances, a process which involves bleaching, deodorization and cooling (to make the oils stable in cold temperatures). The FAO concept includes raw, refined and fractioned oils, but not chemically modified oils. 

12. ANIMAL OILS animal fats that are obtained in the course of dressing the carcasses of slaughtered animals (slaughter fats), or at a later stage in the butchering process when meat is being prepared for final consumption (butcher fats). Butter and similar products obtained from milk. Most animal fats such as meat, butter, cheese and cream contain relatively high levels of saturated fat and as such should be eaten in moderation. Many baked goods such as cakes, biscuits and pastries can also be high in saturated fat.

13. Omega-3 fatty acids Omega-3 fatty acids are found in foods, such as fish and  flaxseed , and in dietary supplements, such as  fish oil . The three main omega-3 fatty acids are alpha-linolenic acid (ALA),  eicosapentaenoic acid  ( EPA ), and  docosahexaenoic acid ( DHA ). ALA is found mainly in plant oils such as  flaxseed , soybean, and canola oils Omega-3 fatty acids are essential nutrients that are important in preventing and managing heart disease. Findings show omega-3 fatty acids may help to:  Lower blood pressure .

14. Omega-6 fatty acids Omega-6 fatty acids  are a family of polyunsaturated fatty acids that have in common a final carbon-carbon double bond in the  n -6 position, that is, the sixth bond, counting from the methyl end.  Members of the family can have pro-inflammatory or anti-inflammatory effects. Basically, the  omega -3s have anti-inflammatory benefits and help prevent heart disease, whereas  omega -6s lower blood cholesterol and support the skin. Like all fats, EFAs provide energy.

15. T H A N K Y O U