Agriculture Reference
In-Depth Information
malic (such as that found in apples) to citric, which actually increases our perception of the
sweetness of the glucose that remains. A whole host of aromatic chemical compounds are
formed - hexanal (which is frequently described as "winey"), alanine and leucine (meaty)
and valine (fruity). Furaneol, which has a characteristic pineapple aroma, is also created,
as are some unusual aroma compounds that are not found in any other fresh fruits, but
which are found in flowers. In addition, the sheer physical softening of the flesh that
comes with ripening increases our perception of flavor.
This ripening doesn't have to happen entirely on the vine. Tomatoes are climacteric
fruits, like peaches and mangoes, and if grown to something approaching physiological
maturity, they can be picked while still solid green and continue to ripen in storage. And as
with other climacteric fruits, this process is encouraged by exposing the fruit to ethylene
gas. In the trade, most of the tomatoes ripened this way are sold as "mature-green," and
they still make up the bulk of the standard tomatoes found in the market. Picked at just the
right moment and ripened this way, a tomato can be adequate, but it will never be great.
Picked a day or two too early, no matter how much gas is applied, it will never devel-
op flavor, even though it may change color. This is particularly troublesome because it is
nearly impossible to look at a whole green tomato in the field and tell whether it is mature
enough to pick - the color is virtually identical to one that is still immature. The only way
to tell for sure whether a green tomato is ready to pick is to cut it open and see whether
the gel around the seeds has softened. Since the growers cut open only a few tomatoes to
check and since tomatoes don't mature uniformly, inevitably a significant percentage will
be so immature that they will never develop any ripe flavors at all. Even so-called vine-
ripe tomatoes are picked at a stage that most of us would consider green, when only the
very first traces of a tan, yellow or pink "blush" appear on the tomato's base.
The holy grails of tomato flavor study are techniques that would tell plant breeders
which varieties have the best flavor, tell growers when tomatoes are ready to be picked
and tell packers and shippers when the fruit is ripe enough to go to the store. Obviously,
every tomato cannot be run through a sensory panel to determine its culinary worth. Just
as obviously, taking apart a tomato's chemical components to try to measure flavor is in-
credibly difficult. One of the latest attempts to understand and measure just what is going
on when we eat a ripe tomato was developed by scientists in Florida, who actually waved
chemical sensors under the noses of people who were chewing tomatoes. Fine-tuning to-
mato flavor at this level is something that could take forever.
Much more practical steps can be taken that would improve tomato taste a lot more
quickly, but the research to discover them is just beginning. Most of the research up until
