Have you ever thought about the color of tomatoes? They come in so many colors these days: red, pink, purple, brown, yellow, white, green, orange, bicolor, and even blue and black! Here’s the breakdown of some of the genetic reasoning behind specific colors of tomatoes, but first let’s talk about what creates the color palette.

Phytonutrients, or nutrients that come from plants, are pigments found in the cell structure and dermal (skin) layers of many plants and are what give fruits, vegetables, and leafy greens their color, scent, and even flavor. They act as the plant’s immune system by protecting them from environmental stresses. Until recently, they were considered nonessential nutrients to our diets, unlike macronutrients—such as carbohydrates, fats, and proteins—or micronutrients—such as vitamins and minerals. But studies have found that, just like plants, our bodies need these nutrients for some of the same reason plants do.

Phytonutrients have antioxidant properties that protect our bodies from free radicals and environmental stress, which slow aging and restore health. They are also anti-inflammatory, helping to protect our bodies from diseases such as cancer, heart disease, and Alzheimer’s. Phytonutrients even help keep our immune system strong by fighting infections.

Now that we know what phytonutrients are and how they can benefit our bodies, let’s look at the phytonutrients specific to providing the colors in tomatoes. There are over 4,000 types of phytonutrients; however, there are three subclasses that present in tomatoes. The first is chlorophyll. Chlorophyll is responsible for the green coloring of unripe tomatoes and some forms of stripes, and it is even found in purple and brown tomatoes, where it’s combined with other pigments to give the purple or brown appearance.

The second class of phytonutrient pigmentation found in tomatoes is carotenoids. Carotenoids are responsible for some of the yellows, oranges, and reds we find in ripe tomato flesh. Two major players for tomatoes in this subclass are lycopene (red) and beta-carotene (orange).

The third subclass of phytonutrient pigments is flavonoids. Flavonoids are found in the epidermis (skin) of tomatoes more than in the flesh. Chalconaringenin is a yellow flavonoid pigment found in the cuticle of the epidermis of some colors of tomatoes; it is not opaque but rather transparent, allowing it to transform the color appearance of the flesh beneath the surface.

Also, in the flavonoid family are anthocyanins, which present some of the deepest pigments of all but have their own subclass of flavonoids that break down the colors even further into blacks, blues, purples, and deep reds. For example, blueberries, blackberries, beets, and eggplants all contain high amounts of this phytonutrient. In tomatoes, it is mostly only visible in the dermal layers with a slight “bleed” into the flesh.

All these pigments work alone or in combination with one another to produce the color of tomatoes as we see them. Please join us next time for a recap of pigments and a breakdown of each color class of tomatoes!