A fresh, ripe, red, scrumptious tomato is a coveted supermarket find during the cold season when pink, paper-flavored baseball tomatoes are piled high. But good flavor does not have to be so rare, according to tomato researchers.

They are learning exactly what tomato chemicals contribute to that vine-ripened taste and they say their findings explain how consumers may be killing much of the flavor in supermarket tomatoes by storing them improperly.Dr. Ron Buttery, a research chemist at the U.S. Department of Agriculture's Western Regional Research Center in Albany, Calif., has studied the chemical components of tomato plants for 20 years.

"Our research is aiming at coming up with a supermarket tomato that tastes as good as a home-grown tomato you pick yourself," he says.

In a study published in the Washington-based American Chemical Society's "Journal of Agricultural and Food Chemistry," Buttery and colleagues report that a key tomato aroma and flavor chemical is three to 10 times as abundant in sliced, vine-ripened tomatoes as in store-bought tomatoes, which typically are picked when they are green.

The chemical cis-3-hexenal is present in minuscule amounts, yet Buttery says it is one of the most potent constituents in tomato aroma and flavor.