Lycopene is an antioxidant commonly found in tomatoes and other red- or pink-colored foods, including watermelon, papaya, rosehips, and pink grapefruit or guava. Evidence suggests that lycopene reduces the risk of cancer, diabetes, osteoporosis and cardiovascular disease, and possibly even male infertility.
Researchers from Ohio State University prepared a sauce from tangerine tomatoes and measured how much lycopene was absorbed over the next 10 hours by those who ate it. Their findings were published in the Journal of Agricultural and Food Science.
They noted that lycopene occurs in two distinct geometric forms — tetra-cis and all-trans. Approximately 95 percent of the lycopene in red tomatoes is of the all-trans variety, whereas tangerine tomatoes contain almost entirely the tetra-cis form. The researchers found that the tetra-cis variety was absorbed 2.5 times more efficiently than the all-trans form.
But the lycopene in tangerine tomatoes may be more fragile than that in other varieties. Because lycopene cannot bind to water molecules, it is hard for the body to separate it from the indigestible fiber in vegetables. This means that absorption of the compound is normally improved by processing, including cooking. The scientists found, however, that tetra-cis lycopene was more likely to break down when heated, as opposed to all-trans, which was unaffected.
Like all-trans lycopene, tetra-cis is also absorbed better by the human body when mixed with oil. Lycopene is a lipophilic compound, meaning that it binds to fats easily.
The benefits of less common varieties of tomatoes are only just beginning to be explored. It is known that the purple coloring in tomatoes comes from anthocyanins, which also create the coloring in various berries and grapes. Anthocyanins are also known to be antioxidants, which protect the body from cell-damaging "free radicals" and decrease the risk of cardiovascular disease and cancer.