Vitamin natural source, carrot

The major dietary sources of retinol are dairy products, eggs and liver, while important sources of /3-carotene are spinach and other dark-green leafy vegetables, deep orange fruits (apricots, cantaloupe) and vegetables (squash, carrots, sweet potatoes, pumpkin). The richest natural sources of vitamin A are fish liver oils, particularly halibut and shark. 

Vitamin A, or retinol, is one of the major fat-soluble vitamins. It is present in many foods the best natural sources are liver, butter, margarine, egg yolk, carrots, spinach, and sweet potatoes. Vitamin A is the precursor of retinal, the essential component of the visual pigment rhodopsin. 

Carotene and lycopene are polyenes occurring in tomatoes and carrots. Carotene is a natural source of vitamin A. Cengage Leaming/Charles D. Winters... 

An alkene, sometimes caJled an olefin, is a hydrocarbon that contains a carbon-carbon double bond. Alkenes occur abundantly in nature. Ethylene, for instance, is a plant hormone that induces ripening in fruit, and o-pinene is the major component of turpentine. Life itself would be impossible without such alkenes as /3-carotene, a compound that contains 11 double bonds. An orange pigment responsible for the color of carrots, /3-carotene is a valuable dietary source of vitamin A and is thought to offer some protection against certain types of cancer. 

Specific sources of vitamin E (ctlphn-tocopherol) include carrots, squash, broccoli, sweet potatoes, tomatoes, kale, cantaloupe melon, peaches and apricots. Vitamin E (Figure 9.19) is the main lipid-soluble antioxidant. It occurs in cell membranes together with polyunsaturated fatty acids in phospholipids, and vegetable oils (especially those rich in polyunsaturated fatty acids) are a major dietary source. It is a phenolic antioxidant, as are most natural antioxidants. 

It may be more expeditious at the community, state, or national levels to enrich and fortify foods of low nutrient quality with amino acids, minerals, and vitamins, than to try to supply foods which naturally contain the optimal quantities of nutrients. This is particularly applicable to situations where foods, which are rich in the desired nutrients, are rejected by the population to be fed. Lor example, there is a high rejection rate for broccoli, carrots, and other vegetable sources of vitamin A in the US. School Lunch Program. Therefore, food technologists have proposed the development of a snack food, like a potato chip, which would contain spinach powder and be fortified with minerals and vitamins. 

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