maillard reaction effects on flavour

2. Louis-Camille
Maillard
(1878 - 1936)
Photographed in
his laboratory
ca 1915
1912 – 1916:
He published 8 papers
on his observations of
colour changes on
mixing amino acids and
sugars.

3. Flavour and Colour in the
Maillard Reaction
H2O
rearrangement
NHROH
OOH
H
OH
OH
Amadori intermediate
carbonyl compounds
 H2O
 RNH2
O
O
H
O
O
O CHO
HO
O
OOH
O OH
O
O CHO
O OH
O
amino acids
FLAVOUR
COMPOUNDS
MELANOIDIN
PIGMENTS
H
O
OH OH
OHOH
OH
R NH2+
reducing sugar amino
compound
Amino acid
or
proteins

4. INTRODUCTION
 Reducing sugars Brown colors
Desirable Undesirable
 Reducing sugars + Amino Acids Free amino acid or
Free amino group of
a protein
MAILLARD
REACTION

5. Maillard Reaction
 Some of the classes of flavor compounds include –
 Nitrogen-containing heterocyclics
 Oxygen-containing heterocyclics
 Sulfur-Containing Heterocyclic

6. Oxygen-containing heterocyclics
 The furanones and pyranones are oxygen-containing
heterocyclic compounds associated with both
caramelized and Maillard flavors
 The odor characters most common to this group of
compounds would be
 caramel-like,
 sweet,
 fruity,
 butterscotch,
 nutty, or
 burnt.

7. Oxygen-containing heterocyclics
Types of oxygen-cont,heterocyclics ,Flavor note
Cyclotene sweet maple
character
3-ethyl-2-hydroxy-2-
cyclopenten-1-one
caramel, nut, maple,
and butterscotch
flavorings
4-methoxy-2,5-dimethyl-
3(2H)-furanone
odor similar to sherry
n-butyl ether derivative
of furanone
jasmine-like odor
oxazoles and
oxazolines
green, sweet, floral,
or vegetable-like
aromas

8. 2,Sulfur-Containing Heterocyclics
 Thiazoles and pyrazines have similar sensory properties

Thiophenes have only been found in cooked or roasted
food products

These compounds, like the thiazoles and thiophenes,
typically are formed via the reaction of sulfur-containing
amino acids with intermediates of the Maillard reaction.

9. Sulfur-Containing Heterocyclics
Types of sulphur-contg.
heterocyclics
Typical flavor note
Thiazoles
alkylthiazoles green, nutty, roasted, vegetable, or
meaty notes
Trimethyl thiazole cocoa, nutty character
2-isobutyl thiazole strong, green odor of tomato leaf
important to tomato flavor
2,4-dimethyl-5-vinyl thiazole nut-like odor
2-acetyl thiazole nutty, cereal, and popcorn flavor
Thiophenes
Thiophene Pungent character
2,4-dimethyl thiophene flavor of fried onions
2-acetyl-3-methyl thiophene honey-like sensory quality at 0.25
g/100 L

10. NITROGEN CONTG. HETEROCYCLICS
Pyridines
 Pyridine compounds appear to be less widely
distributed in browned foods than the pyrroles and
pyrazines
 green notes are quite common
 The contribution of the pyridines to browning flavor is
dependent on the individual pyridine formed and its
concentration in the food.
 At low concentrations, the pyridines typically
contribute very pleasant notes. However, they
generally become harsh and offensive at higher
concentrations.

11. Types of nitrogen-contg.
heterocyclics
Typical flavor note
Pyridines
3-methyl pyridine green odor
3-methyl-4-ethyl pyridine sweet and nutty
Pyridine pungent
2-acetyl-pyridine tobacco-like

12. Food processing and maillard reaction
products;effect on human health and nutrition
 Meat processing and MR
 MR on Milk processing
 Coffee bean processing and MR
 Pasta processing and MR
 Soybean processing and MR

13. C0nclusion and perspectives
maillard reaction products have both positive and negative impacts on health.
Diverse MRPs act as antioxidants, bactericidal, antiallergenic, antibrowning,
prooxidants, and carcinogens.
Most of these properties depend on processing of food. High temperature heating
makes some food nutritious, whereas some of the foods lose their nutritional value.
Many strategies are employed in the food industries to reduce the production of
MRPs.
For example, acrylamide has been classified as a probable carcinogen to humans by
the International Agency for Research on Cancer .
During food preparation at high temperature, acrylamides are formed in many types
of foods via Maillard reaction .
To reduce the amount of acrylamide, asparaginase has been successfully used in
laboratory for potatoes and cereals . It has also been reported that injection of
CO2during extrusion process helps to reduce the level of acrylamide .