A lot of things cause arguments at Christmas time. Bad
gifts, cooking disasters and a room full of relatives who spend the rest of the
year apart for a reason… yet few things divide opinion as greatly as the humble
Brussels sprout. Some view them as an essential part of Christmas dinner, and wonder
out loud why they’re not eaten all year round. The remainder silently wonder
what their ancestors were thinking when they made these little Grinch-green
blobs a tradition. Yet dig a little deeper, and the Brussels sprout is a pretty
interesting vegetable. If you find yourself spending less time eating them than
staring at them as they go cold on your plate, why not at least appreciate
these little vegetables for their trivia?
A Sprout Family Christmas
Sprouts smell like cabbages. They taste like cabbages. They
look like miniature cabbages. So it’s fair to assume they’re related to
cabbages. You’d be right- they’re actually the same species. A large number of
our traditional green vegetables are descended from a single wild species,
called Brassica oleracea, or wild
mustard.
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| Yum? |
By selectively breeding different parts of the plant to grow large and
edible, humans have created a diverse range of vegetables collectively known as
brassicas. For example, the roots of one lineage have been bred to swell up and form the vegetables we know as
turnips. Cauliflower, as suggested by its name, is literally a bunch of tiny
flowers, as is broccoli. Breeding for exaggerated stems makes kohlrabi, whilst cabbage
and kale are different varieties of leaf, and mustard is obtained from plants
bred for particularly pungent seeds. Brassicas are essentially the domestic dogs
of the vegetable world; a collection of artificial “breeds” so distinct from
one another, you’d be forgiven for thinking they were different species.
The Brussels sprout is descended from the buds of the plant, and the way in
which they grow is unfamiliar to most people. They bud out of a thick central
stem, growing in a spiral formation from top to bottom.
Here’s a fine specimen out the garden. Notice how the older
sprouts towards the base have opened into perfect little cabbage-y florets as
they move beyond the bud stage to become fully-formed leaves.
An acquired taste?
What makes sprouts and other brassicas divide opinion so
much? If your rejection of sprouts leads others to call you a fussy eater, it
might not be your fault-- the distastefulness might actually be written into
your genes. Our tongues are covered in taste receptors, and the most diverse
group of these are the TAS2 receptors, which allow us to detect a whole host of
different bitter compounds. Though having a complex appreciation of the least
popular flavour out there might seem pointless, it’s actually paramount to our
survival: most poisonous substances are bitter, so it pays to be able to detect
them. One gene coding for a particular TAS2 receptor comes in two forms, and
which variety you have determines your ability to taste certain harmless but bitter compounds commonly found in brassica vegetables. People who carry the
sensitivity gene will experience sprouts as being unpleasantly bitter, to the bafflement of non-carriers. This effect is enhanced in young children who carry the sensitivity
gene, as they can detect much lower concentrations of the bitter compounds than
adults. This is partly why some kids learn to love-- or at least tolerate--
sprouts as they get older.
