Why Tomatoes Look, But Don’t Taste Ripe

November 11, 2008

When I first started cooking, I read in a cookbook that unless you’re able to get tomatoes at their peak of freshness in season, it’s better to buy them canned.  I was surprised, as I had always assumed that fresh produce tasted better.  The book explained that canned tomatoes were always picked at the peak of freshness, while fresh tomatoes at the grocery store were often not, due to shipping times.

This makes sense, and I experienced it a couple months ago buying a few tomatoes from a grocery store down the street.  They just didn’t taste like anything. I opened up McGee to see if he had a more detailed explanation.  According to McGee, tomatoes that fully ripen on the vine build more sugar, acid, and aroma compounds, giving them more flavor.

An important element of ripe-tomato flavor is provided by the aroma compound furaneol, which resembles sweet-savory caramel (it also contributes to the flavors of ripe strawberries and pineapples).

So canned tomatoes can be picked when ripe and canned, preserving their fresh flavor.  What I found most interesting, however, is what happens with supermarket tomatoes.

McGee explains that most supermarket tomatoes are picked while still green. They are then shipped to the supermarket and reddened artificially with ethylene gas (the gas isn’t bad, it is naturally in plants and helps control ripening).  This means that many red tomatoes you see in stores never had a chance to gain their flavor and were turned red to look more appealing.

Posted in Food Science |