Lipids -Meaning and functions of lipids
For human survival, all the nutrients that are found in food are needed by the body. Lipids are vital and important fats that perform the various function in the human body.
People mistaken fat for fattening. Our ability to store excess caloric energy as fat for future usage allowed us to continue human beings. Normal fat reserves are a signal that metabolic processes are efficient and a person is healthy.
What are lipids?
Lipids are groups of organic substances originating from living matter that is insoluble in water. Fats and oils can also be called lipids. Fats and oils are made up of carbon, hydrogen and oxygen. The content of carbon and hydrogen is higher than that of oxygen.
Fats are usually solid at ordinary temperature. Oils are usually liquid at ordinary temperature. Lipids are classified into two namely: simple lipids( monoacylglycerol) and Compound lipids (phospholipids). The end product of fays and oils is fatty acid and glycerol.
Functions of fats and oils in the body
- Fats and oils supply the body with energy. This is because they contain more hydrogen components in proportion to oxygen than carbohydrates. They combine with more oxygen to produce more energy. Energy is needed to power the muscles for all the physical work and play an average person or child engages in. For example, energy stored in the muscles of athlete, footballers, wrestlers and boxers helps them a lot. Lipids are major sources of energy in animals and high lipid-containing seeds.
- They serve as covering and protections to some vital organs of the body. Some vital organs of the body like the kidney, heart, liver, breast, brain among others.
- They act as lubricants in the intestine. This helps the intestines to perform their functions properly.
- Lipids provide vitamins as well. For example, vitamin A can be found in palm oil.
- Fats add flavour to a meal when it is cooked.
- Some food that has fats contain essential fatty acids
- Fat found under the skin of mammals acts as insulators and prevent loss of heat from the body.
- They work hand in hand with the cell membranes.
- Finally, fats add flavour to a meal especially when it is cooked.
The digestion process of fats and oils
Fats and oils are broken down in the mouth because of its fragile nature. From the mouth, it passes into the stomach. The secretion of cholecystokinin hormone from the intestinal gland which stimulates the gall bladder to release bile and bile salts.
They combine to emulsify fats and oils. The fats and oils are then passed to the small intestine; they are acted upon by the pancreatic lipase and enteric lipase. After this, the fats and oils are converted to fatty acid or glycerol. Fatty acid is over forty but only three are known as essential fatty acids because they cannot be produced by the body.
Food sources of fats and oils
Just as proteins have both plant and animal sources, fats and oils are gotten from both plant and animal.
Animal source of fats and oils: All animals have fats and oils. They are
(a) milk which can be gotten from cow and goat only.
(b) fatty meat which can be found in chicken, pork (pig), beef (cow), and
(c) almost all the fishes have oils in them. For example salmon, herring, shellfish, sardine, trout, catfish, shark, hemming, haddock and flounder.
Plant source of fats and oils: Some plants are rich in oil most especially. For example,
(a) Avocado pear and small pear are fat and oil-filled. It is used to produce avocado oil.
(b) Coconut is another source of fats and oils. It is used to produce coconut oil which can be used in cooking, making body or hair cream.
(c) Palm oil tree contains fat and oil. The flesh on its seed is used in producing red palm oil (cooking). Even the kernel is used in producing oil known as palm kernel oil.
(d) All nuts contain fats and oils. They are groundnuts (groundnut oil), almond nuts, cashew nuts, peanut oil, olive oil (olive tree), soya beans oil (from soya beans), canola oil gotten from canola tree and castor oil from castor tree.
(e) Melon: Although melon seeds are rich in protein, they also have oil in its seeds. When the seeds are dried and pressed, melon oil can be gotten.