Control strategies of pyrazines generation from Maillard reaction

Pyrazines is a group of volatile heterocyclic nitrogen-containing compounds contributing to baking, roasted, and nutty flavors in food products. Maillard reaction (MR) is an important mean of synthesizing pyrazines. As welcomed volatile compounds, the generation of pyrazines from the MR are expected to be promoted during food processing. On some occasions, the MR needs to be suppressed for minimizing the formation of harmful MR products (MRPs), undesirable color, and off-flavors, but in turn, inhibiting the formation of pyrazines simultaneously. Control strategies of pyrazines generation from the MR were emphasized in this review, including utilization of new reactants, modification of reaction conditions, and adoption of emerging techniques. Ammonia released from the pyrolysis of amino sources significantly promoted the generation of pyrazines. Peptides-involved MR systems generally synthesized more types and higher content of pyrazines, which depended on the structure of N-terminal amino acid in the peptide. The oil-in-water MR emulsions generated more pyrazines due to numerous lipid oxidation products imparted into the MR as intermediates. Emerging technologies, such as ultrasound promoted the pyrazines formation in MR model systems due to an extremely high temperature and pressure environment favored by the MR. Some other strategies suppressed the MR for minimizing the generation of harmful MRPs and meanwhile, inhibiting the formation of pyrazines, e.g. high-pressure processing, addition of phenolic compounds, and utilization of low reactive pentapeptide and ketohexoses. The strategies summarized in this review are applicable for achieving pyrazines control in the food industry.