during its trip to the store. Other flavour and
aroma components emerge from reactions
between sugars, amino acids, or fatty acids as
the meat is cooked.
Central to this is myoglobin, a protein in
muscle cells that carries oxygen. Myoglobin
contains heme, a porphyrin ring with an iron
atom bound in the centre. When myoglobin
denatures as meat cooks, it releases the
heme. Some iron in turn escapes the heme
and catalyses flavour- and aroma-forming
reactions. The iron in myoglobin is also
responsible for the colour change of meat
as it cooks, oxidizing from a red Fe(II)–heme
complex to a brown one that contains Fe(III).
This 100% plant-based burger from
Impossible Foods gets its colour from a
protein called leghemoglobin. Image Credit:
Impossible Foods.
believes consumer demand for his products
will unseat animal agriculture as the source of
beloved burgers.
There’s something about the combination of
muscle, connective tissue, and fat that makes
up meat that is unmistakable. As Brown notes,
the taste of meat cannot be confused with
anything else. And, he says, people do not
love meat because it comes from animals or
uses too many resources, but because of its
deliciousness. To achieve a fake meat that will
convert meat lovers requires homing in on the
flavour, aroma, texture, and appearance that
gives meat its essence. There’s opportunity to
boost nutrition, too: providing more protein
than beef without cholesterol, hormones,
or antibiotics. This combination is what
Impossible Foods is chasing.
Meat flavours and aromas come from
thousands of volatile small molecules released
by muscle and fat cell destruction. Flavour
precursors start with an animal’s diet, which
influences the molecular composition of
its cells. After slaughter, enzymes in an
animal’s muscle cells begin breaking down
biomolecules into simpler amino acids, sugars,
and fatty acids. This means some flavour
molecules develop even as the meat ages
AgriKultuur |AgriCulture
A key, then, to making a convincing plant-
based burger, according to Brown, is
recreating these reactions. Impossible Foods
has focused on leghemoglobin, a protein like
myoglobin that is found in nodules on the
roots of legumes. Company scientists are
producing this protein in yeast and adding it
to their burger to do the chemistry needed to
make meaty flavours and aromas.
To recrea