Many of you
would like to eat fruits and vegetables, because it’s contain fiber, vitamins
and anti-oxidants that are essential for our body. But however, maybe you have
had infuriating experiences while peeling apples, yam, potato, or banana and
suddenly found that the color of a fruit or vegetable you peel browning, so the
color of the fruit or vegetables you serve become invisible beautiful and not appetizing
anymore. Sometimes not only the color changes occured but also followed by a
change of taste, smell, texture and nutritional value itself. The process that
occurs in the fruit or vegetable is known as browning or browning..
Banana which was
one of the most easiest browning fruit found a lot in Indonesia. There is also a
wide variety of traditional food can be made from banana. Some of them take an
advantage of the browning process, such as ‘Sale Pisang’. If we used to prevent
discoloration in fruits, the banana was left discolored naturally instead with
the process of drying in the sun to help reduce the water inside. Equal process
can also be used in the manufacture of raisins to create color and flavor
desired.
Actually, the browning
process can occur in enzymatic and non-enzymatic way. So what is an enzyme?
Enzymes are protein molecules functioned as biocatalystator, or it can simply
be defined as a compound that plays a role in speeding up the body's chemical
processes in living organisms. The browning processes that occur in fruits and
vegetables that you often meet is usually the enzymatic one, because there is
an enzyme involved in the process. When fruits or vegetables are being peeled
or cutted, they will release the enzyme in their cell generally. The process of
stripping or cutting interfering the chemical composition in the plant tissue
(Fruits and vegetables). So that these chemicals will come into contact with
oxygen in the air. Fenolase enzyme catalyze the change of phenolic compounds on
plant to form brown pigments known as melanin. Moreover, the presence of iron
or copper on the knife that we use also accelerates the speed of this browning reaction.
There are so many
ways you can use to prevent the browning process. You can soak the fruit or
vegetables you peel or cut into the cold water that was able to prevent direct contact
between the plant tissue with oxygen in the air. Another simple ways is by
adding lemon juice to the peeled fruit or vegetable, ascorbic acid in the lemon
function as an antioxidant. As for the prevention, oxygen will tend to react
with ascorbic acid compared with phenolic compounds in the fruit or vegetable. The
browning process can be prevent until all of the ascorbic acid completely
reacts with oxygen. Heating process can also be used to prevent browning
process because heat turning off the polyphenol oxidase enzyme. However, this
method can only be applied for ripe fruit and vegetables.
Increasing acidity
or lowering the pH of the fruit can be done to prevent the browning process. Increasing
the pH value or acid levels will cause the enzyme polyphenol oxidase in
inactive phase. Citric acid can act as a chelating agent or substance that was capable
of binding and control metal ions. So the copper or iron ions from a knife or
cutting tool we use to peeled can be bound by citric acid.
Post a Comment