Impact of enzymatically generated peptides on the formation of alkylpyrazines in Maillard model systems and baked food products

The Maillard reaction is the major route for thermal generation of flavor; it is a very complex cascade of interdependent chemical reactions that has been the topic of many research papers since it was first identified by Louis Camille Maillard in 1912. The aromas in most thermally processed foods, such as bread, cereal products, roasted peanuts, and roasted coffee, are largely due to the Maillard reaction. Currently, more than 2500 different flavor compounds have been identified. Among these Maillard–type flavors, heterocyclic compounds with desirable aromas and low odor thresholds make the most significant contribution. Pyrazines are specific Maillard reaction products known to contribute to the unique roasted, nutty, meaty, earthy, popcorn-like aroma of many heated foods. The generation of pyrazines has been studied extensively in model systems between free amino acids and sugars and studied less in more complex model systems. Nevertheless, in general, food products are known to contain small amounts of free amino acids. Therefore, the main goal of the research was to study the formation of pyrazines in different Maillard model systems containing peptides, proteins, amino acids, and glucose in a variety of conditions that can be related or applied in the food industry. The generation of pyrazines and their formation mechanisms were studied in several model systems. Further, the generation of these volatiles was studied in two different baked food products