Heating is commonly used in many food processing and preparation systems and chemical reactions result with added or naturally containing sugars transformed to non-enzymatic browning products by way of the Maillard reaction or caramelization.
Their products can be divided into small molecule products, which are the important sources of food flavor, food aroma and colorless intermediate products and the finally formed browning macromolucular products, i.e. the browning products, which confer the food colors.
L -Cysteine is known to be one of the most important precursors of meat-like flavor compounds. L-Ascorbic acid is a common ingredient of the human diet, especially in fruit and vegetables, herbs, and to a lesser extent in meat. In food industry, lysine is commonly used as the food fortifier and feed additive.
L-ascorbic acid is an important nutrient for human beings and is also widely present in the nature. In food processing, L-ascorbic acid is widely used as food additive, anti-oxidant, and flour improver in bakeries.
Research shows that the effect of pH on the formation of aroma compounds from L-Ascorbic acid and L -Cysteine during the non-enzymatic browning reaction and discovered that the reaction between L-Ascorbic acid and L -Cysteine led mainly to the formation of alicyclic sulphur compounds, thiophenes, thiazoles, and pyrazines.
Caramelization is a nonenzymatic browning reaction of sugars providing a caramel-like flavor during high temperature treatments of foods. It is the process of removal of water from a sugar followed by isomerization and polymerization steps. Baking times and temperatures are similarly important for caramelization of non-reducing (sucrose) and reducing sugars to produce brown color polymers such as caramelans, caramelens, and caramelins, as well as volatile chemicals which produce characteristic caramel flavor.
Non-enzymatic browning reactions
