Download The carbonyl group of the reducing sugars reacts with the amino

Ashley Brannan
March 30, 2014
English 202c Section 902
The Maillard Reaction within Food
Introduction
As incoming freshman into the Nutritional Sciences field at college, you will encounter the
reaction that is thought to be one of the most important flavor inducing methods you can use while
cooking foods. This document is going to give the overview of the Maillard Reaction. The reaction is the
process in which an individual browns a food without burning it and gives the food an increased
intensity in flavor. This reaction is a non-enzymatic (enzymes from the food are not used in this reaction)
browning reaction of the food. Within this process, the browning reaction occurs due to the heating of
proteins and sugars (glucose, sucrose, maltose, etc.) which then connect to free amino acid groups
(lysine, alanine, etc.). This reaction is used on many foods such as pan seared steaks, breads, and
condensed milk when it is left in the can in the fridge.
History
The Maillard reaction was first described by Louis-Camille Maillard in 1912 while he was attempting to
reproduce biological protein synthesis and then published into a paper when he explained what had
happened. However, a chemist John E Hodge published a paper in 1953 that established the mechanism
for the Maillard reaction.
The Process
The Maillard reaction occurs between the carbonyl group (a double bond between a carbon atom and
oxygen atom as seen in Figure 1) of the reducing sugar and the amino group of the amino acid.
Figure 1.
This image depicts the functional
group known as the carbonyl group.
The carbonyl group of the reducing sugars reacts with the amino group of the amino acid to produce a
biochemical compound that consists of an amine with a glycosidic bond to a carbohydrate which is
called N-substituted glycosylamine (N-Glycosylamine) and water (Figure 2).
Figure 2.
This is the reaction
between the Reducing
sugar and the amino
compound to form a
N-substituted
Glycosylamine.
This newly formed N-Glycosylamine then undergoes a rearrangement to form a more stable ketosamine
(which is just a technical term for the combination of two functional groups, ketoses and amines) which
the actual form is dependent on the starting food that is undergoing this process. The final products
from this reaction are brown nitrogenous polymers and copolymers called melanoidins (Figure 3). These
are the compounds that give your foods flavor and aromas that make foods flavors more interesting.
This reaction occurs more readily between the temperatures 148.9 degrees Celsius and 260 degrees
Celsius.
Figure 3.
This figure shows the specific
melanoidins that are created
when coffee beans are roasted.
What Types of Foods Does This Process Effect?
This process has many incidents within food preparation and can be seen during cooking of foods at high
temperatures such as roasting, baking, and sometimes for storage for prolonged periods (figure 4).
Figure 4 depicts a more simplified version of the reaction that I described above allowing for individuals
to more accurately describe what is happening within specific foods that have gone through the Maillard
reaction.
This reaction occurs within these foods most commonly:
-
Toast
Beer
Bread
Chocolate
-
Coffee
Syrup
Meats that are cooked with the
technique of pan searing.
Figure 4. This is a more simplified version of the information given to you in the process section of this
document.
Why It Is Important to You?
This is important to you as an incoming freshman to college because during your nutrition courses, you
will be shown the significance and the reasons you must use this reaction instead of the multiple others
that are able to occur within foods that are being heated. This reaction is to be used when you do not
want to actually crystalize the sugar within the food, such as in the reaction of caramelization, but want
to just brown the outside to create a more flavorful taste from the food.
Conclusion
As an incoming freshman into nutritional sciences, you will now have a head start on one of the most
important reactions that you will learn about in your classes. This reaction will not only help you in
determining the best flavor for a food but the best way to cook a food as well.