Lycopene is widely found in tomatoes, tomato products, watermelon, grapefruit and other fruits. It is the main pigment in ripe tomatoes and one of the common carotenoids. In 1989, MASCIO found that lycopene had the highest quenching activity against singlet oxygen of all carotenoids. Subsequently, the research on the function of lycopene has become a hot topic, including the absorption and metabolism of lycopene, the reduction of lycopene in prostate cancer and other tumors and cardiovascular diseases, as well as the extraction and determination methods of lycopene. Currently, lycopene is not only widely used as a natural pigment, but also increasingly used in functional food, medicine and cosmetics.
Lycopene is an unsaturated olefin compound, which is the main pigment in ripe tomatoes and one of the common carotenoids. Lycopene does not have the actino-angelicone ring structure of beta-carotene, so it cannot be converted into vitamin A in the body, and is not A source of vitamin A. The molecular formula is C40H56. Lycopene is a fat-soluble substance, insoluble in water, methanol, ethanol, soluble in ether, petroleum ether, hexane, acetone, soluble in chloroform, carbon disulfide, benzene and other organic solvents. There are 11 conjugated double bonds and 2 non-conjugated double bonds in the lycopene molecule, so its stability is very poor, and it is prone to cis-trans isomerism and oxidative degradation. Factors affecting the stability of lycopene include oxygen, light, heat, acids, metal ions, oxidants and antioxidants.
The absorption rate of lycopene was higher than that of beta-carotene and beta-carotene, but it was also affected by many factors. Lycopene is more readily absorbed in the cis configuration than in the trans configuration. Most of the naturally occurring lycopene is in the all-trans configuration, while most of it is in the cis configuration (>50%) in human tissues, and the proportion of the cis configuration in the body does not change with the difference of the lycopene configuration in food. Currently, it is believed that most of the trans – configurated lycopene is cis – configurated in the gastrointestinal tract before absorption. Dietary proteins such as beta-carotene complexes, large amounts of soluble dietary fiber (if glue), binding cholesterol and resins, and lack of iron, zinc and protein, as well as intestinal diseases can interfere with lycopene absorption. Heat processing can change the trans structure of some natural lycopene into cis structure, and the lipids in food matrix can promote the release of lycopene, and the lycopene after heat treatment with oil is more easily absorbed than the unprocessed lycopene.
Lycopene is mainly distributed in the testis and adrenal glands, but also in the liver, adipose tissue, prostate and ovary. Lycopene was not detected in brain tissue (suggesting it may not be able to cross the blood-brain barrier into brain tissue). There was a positive correlation between lycopene concentration in blood and tissue in a certain dose range. About 50% of the carotenoids in the human body are lycopene, and lycopene is one of the main carotenoids in human milk.
Lycopene has a long chain polyunsaturated olefin molecular structure, so it has a strong ability to eliminate free radicals and antioxidant capacity. Current studies on its biological effects have focused on antioxidant, cardiovascular disease risk reduction, genetic damage reduction and tumor development inhibition.
Enhance the ability of oxidative stress and anti-inflammatory effect
Oxidative damage is considered to be one of the main causes of increased incidence of cancer and cardiovascular and cerebrovascular diseases. The antioxidant capacity of lycopene in vitro has been confirmed by many experiments. The ability of lycopene to quench singlet oxygen is more than 2 times that of beta-carotene, a commonly used antioxidant, and 100 times that of vitamin E.
Protect the cardiovascular system
Lycopene can go deep to remove vascular waste, regulate plasma cholesterol concentration, protect low-density lipoprotein (LDL) from oxidation, but also repair and perfect the oxidized cells, promote the formation of intercellular glia, enhance vascular flexibility. In one study, serum lycopene levels were negatively correlated with the risk of cerebral infarction and cerebral hemorrhage. Studies on the effect of lycopene on atherosclerosis in rabbits have shown that lycopene can effectively reduce the levels of serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (ldl-c) in rabbits, and its effect is similar to that of fluvastatin sodium. Other studies have shown that lycopene has a protective effect on cerebral ischemia, and it mainly inhibits the activity of glial cells through antioxidant and free radical scavenging, and reduces the area of cerebral perfusion injury.
Protect the skin
Lycopene also has the ability to reduce skin exposure to radiation and ultraviolet (UV) rays. When UV irradiate the skin, the lycopene in the skin combines with the free radicals produced by UV to protect the skin from damage. Some studies have shown that foods rich in lycopene can fight UV and prevent red spots caused by UV exposure. Lycopene can also quench free radicals in epidermal cells, and it has obvious discoloration effect on old age spots.
Lycopene is becoming more and more popular as people pay more and more attention to dietary health. In addition, the feed additives and other aspects are also concerned. The research shows that lycopene used in aquaculture can make aquatic animals’ body color bright and improve their quality. Mix with lutein to make carotenoid preparation, can prevent animal vitamin deficiency. At present, lycopene is produced by microbial fermentation. The production cycle is short, and the production is not limited by the site and season. With the deepening of research and the emergence of innovative products in various fields, lycopene has a good application prospect.
Post time: Apr-10-2020