The browning of these food stuffs is due to Maillard Reaction creates flavor and changes the color of food generally only begin to occur above 285°F occurs between amino acids

1. Food Browning by Maillard
Reaction
Article written and published
By
www.worldofchemicals.com

2. INTRODUCTION
 When you chopped onion and fried on
pan, and added the onions together with
a pinch of baking soda did anybody taste
of the browned onions are remarkably
sweet and caramel-like, and compared
with conventionally browned onions, they
were softer!
 When you cook meat have you
wondered why the meat changes color at
different stages of cooking?
 But this was observed 102 years back
itself by Louis-Camille Maillard.

3. BRIEF HISTORY
 The browning of these food stuffs is due to
Maillard Reaction / Non enzymatic
browningas part of his PhD thesis in the
year 1912 and are therefore known as the
Maillard reaction.
 Browning, or the Maillard reaction, creates
flavor and changes the color of food, the
taste and color to baked bread and even the
turning of beer brown. Maillard reactions
generally only begin to occur above 285°F
(140°C).
 Until the Maillard reaction occurs meat will
have fewer flavors. High-temperature
processes in particular, such as frying,
roasting, grilling, and baking, rely heavily on
the Maillard reaction for the characteristic

4. WHAT IS Maillard browning ?
 Maillard browning is a chemical reaction that
usually occurs between amino acids (the building
blocks of protein) and those carbohydrates known
as reducing sugars – although the reaction has
been known to occur between reducing sugars and
whole proteins.
 In a Maillard reaction, the reactive carbonyl group
of a reducing sugar molecule reacts with the
nucleophilic group of an amino acid, causing a
change in color (usually darkening of color)
and flavor of a food product.
 Heat (energy) is usually required for a Maillard
reaction to proceed. Reactions between reducing
sugars and free amino acids occur easily and with
very little heat required. Reducing sugars will also
easily react with the reactive terminal end amino
acids of hydrolyzed proteins and, again, very little
heat is required.

5. WHAT IS Maillard browning Cont
..
 Reactions between reducing sugars and
amino acids that are part of a whole protein
are less common and require more heat
(energy) to proceed.
 In the food industry, the troublesome Maillard
reactions that occur over shelf life time are
usually those reactions between reducing
sugars and free amino acids or small
peptides that result from protein hydrolysis
that occurred during food processing.
 The visible result of a Maillard reaction is
development of a darker color called
browning. A flavor change usually
accompanies the development of the darker
color.

6. WHAT IS Maillard browning
Image

7. Products with Maillard
reactions
 The Maillard reaction is responsible for many colors
and flavors in foodstuffs:
 • Caramel made from milk and sugar
 • The browning of bread into toast
 • The color of beer, chocolate, coffee, and maple syrup
 • The -tanning products
 • The flavor of roast meat
 • The color of dried or condensed milk
 • 6-acetyl-1,2,3,4-tetrahydropyridine is responsible for
the biscuit or cracker-like odor present in baked goods
like bread, popcorn, tortilla products.
 • 2-acetyl-1-pyrroline flavours aromatic varieties of
cooked rice. Both compounds have odor thresholds
below 0.06 ng/l.

8. Amino Acids
 Amino acids are biologically important organic
compounds composed of amine (-NH2) and
carboxylic acid (-COOH) functional groups, along
with a side-chain specific to each amino acid.
 The key elements of an amino acid
are carbon, hydrogen, oxygen, and nitrogen,
though other elements are found in the side-chains
of certain amino acids. Since 2001, 40
non-natural amino acids have been added into
protein by creating a unique codon (recoding)
and a corresponding transfer-RNA: aminoacyl -
tRNA-synthetase pair to encode it with diverse
physicochemical and biological properties in
order to be used as a tool to exploring protein
structure and function or to create novel or
enhanced proteins.

9. Amino Acids Cont …
 Experts classify amino acids based on lots of
different features. One of them is whether or
not people can acquire them through the diet.
According to this factor, scientists recognize 3
types: the nonessential, essential, and
conditionally essential amino acids.
 Those 8 called essential (or) indispensable
can't be produced by the body and therefore
should be supplied by food: Leucine,
Isoleucine, Lysine, Threonine,
Methionine, Phenylalanine, Valine, and
Tryptophan. One more amino acid, Histidine,
can be considered semi-essential, as the
human body doesn't always need dietary
sources of it.

10. Amino Acid Classifications
 Nonessential ones are produced by the human body
either out of the essential ones or from normal proteins
breakdown. These include Asparagine, Alanine,
Arginine, Aspartic acid, Cysteine, Glutamic
acid, Glutamine, Praline, Glycine, Tyrosine, and Serine.
 One more classification depends on the side chain
structure, and experts recognize 5 types in this
classification:
 1. Sulfur (Cysteine and Methionine)
 2. Neutral (Asparagine, Serine, Threonine, and
Glutamine)
 3. Acidic (Glutamic acid and Aspartic acid) and basic
(Arginine and Lysine)
 4. Alphatic (these include Leucine, Isoleucine, Glycine,
Valine, and Alanine)
 5. Aromatic (these include Phenylalanine, Tryptophan,
and Tyrosine)

11. Amino Acid Classifications
Cont..
 Amino acids also classified based on structure of the
side chain that divides the list of twenty into 4 groups,
two of which are main groups and two are subgroups:
non-polar, polar, acidic and polar, basic and polar.
 For example, side chains having pure hydrocarbon alkyl
or aromatic groups are considered non-polar, and their
list includes Phenylalanine, Glycine, Valine, Leucine,
Alanine, Isoleucine, Proline, Methionine, and
Tryptophan. If the side chain contains different polar
groups like amides, acids, and alcohols, they are
classified as polar. Their list includes Tyrosine, Serine,
Asparagine, Threonine, Glutamine, and Cysteine.
 Further classification goes for acidic-polar (includes
Aspartic Acid and Glutamic Acid), if the side chain has a
carboxylic acid, and basic-polar (includes Lysine,
Arginine, and Histidine), if the side chain contains an
amino group.

12. How to eliminate the negative
effects of the Maillard
reaction?  Acrylaway is an enzyme that cannot be seen
or tasted in the food. It can only be measured
through advanced laboratory equipment.
 During the Maillard reaction, the
asparaginase Acrylaway can reduce the
mitigation of acrylamide by up to 90 per cent,
and can be used in a broad range of foods
such as biscuits, cookies, crackers, French
fries, crisp and toasted bread, fried and
baked snacks, and breakfast cereals –
without changing the taste or appearance of
the product.

13. References
 http://www.worldofchemicals.com/456/chemis
try-articles/food-browning-by-maillard-reaction.
html
 [1] © From,
http://idahomilkproducts.com/content/what-exactly-
causes-maillard-browning
 [2] © From,
http://blog.khymos.org/2012/06/04/maximizin
g-food-flavor-by-speeding-up-the-maillard-reaction/
 [3] © From,
http://www.acrylaway.novozymes.com/en/the-natural-
solution/food-processing/the-maillard-reaction/
Pages/default.aspx