The Maillard reaction is not a single reaction, it is a complex series of reactions between amino acids and reducing sugars, usually at elevated temperatures. It is a kind of non-enzymatic browning, such as caramelization. The commercial success of food products exposed to microwave technology plays a major role in the color and aroma of the product. It is especially important to achieve the color and aroma that is generated by the Maillard reaction.
In this process, hundreds of different flavor compounds are produced. These compounds break down into new flavor compounds. During the Maillard reaction, very specific flavor compounds are formed in each type of food.
Maillard reactions are important in all oven-baked, fried or other heat-treated foods. Maillard reactions are responsible for the flavor of bread, cookies, cakes, meat, beer, chocolate, popcorn, rice. In many cases, like coffee, flavor is a combination of Maillard reactions and caramelization. However, while caramelization occurs only above 120-150 ° C, Maillard reactions occur at room temperature.
On the other hand, in foods exposed to microwave heating / cooking, color and aroma changes due to Maillard reactions cannot be seen in foods cooked by conventional methods.
In addition, the loss of aromas generated in the process or added later during microwave cooking is much greater than in conventional methods.
Factors such as the difference between microwave and conventional cooking mechanisms, the composition of the food, and the design of the microwave oven cause the desired color and aroma not to be achieved.
Microwave heating affects the formation of Maillard reaction in food in two ways;
-relationship between microwaves and food
-effect of microwave heating on chemical reaction
Color, volatile aroma compounds, final amounts of products resulting from Maillard reaction of non-volatile compounds; temperature, humidity, pH and heating time.
The addition of different salts such as NaCl, CaCl2 and Na2SO4 increases both browning intensity and formation of aroma compounds. Increasing the electrolytes and pH increases the speed of Maillard reactions in microwave model systems. Although it is related to the ionic conduction mechanism in microwave application, it is also related to the change of water activity by adding salt to the medium.