Others say that ripe red tomatoes are the key ingredient.

WSJ: Salmorejo the Way Mama Makes It

To prove it worked, he started with a strain of the E. coli bacterium that produced small quantities of lycopene, the pigment that makes tomatoes red.

FORBES: Putting Evolution to Work

Another antioxidant, lycopene, found in foods like canned tomatoes and red grapefruit juice, also promotes skin health.

CNN: What you eat can improve your health, mind, and appearance

Add tomatoes, a few glugs of red wine, some crushed red pepper and a handful of fresh basil.

NPR: Savoring Memories of Sunday Dinner

They are a thinking person's dish, conjuring up old food memories such as tomatoes, lemon and basil, or red peppers, but delivering them in a surprising, new package.

NPR: Cranking Up Savory Sorbet

Picnic tables will groan underneath the weight of piles of cole slaw, potato salad, baked beans, fresh tomatoes out of the garden and spectacularly decorated red, white and blue cupcakes.

FORBES: Taxes and Independence: Happy Fourth of July

In fact, they get green tomatoes sprayed with ethylene gas to make them turn red.

FORBES: Magazine Article

Many Americans suffer tomatoes so pallid and tasteless that they must wonder: Why not just sell red-tinted cardboard instead?

FORBES: Not seeing red