Pyrazines: Synthesis and Industrial Application of these Valuable Flavor and Fragrance Compounds

Abstract

Alkyl pyrazines-other than being extracted from variousnatural sources such as coee beans, cocoa beans, and vegetables-canbe synthesized by chemical methods or by certain microorganisms.The importance of pyrazines for the food industry is expected to grow inthe upcoming years due to the higher demand for convenience products. Theroasty, nutty, and earthy smell is reminiscent of coee and cocoa, dependingon substitution and concentration of pyrazines. The growing awarenessof people about the ingredients and the origin of their daily food hasstrongly influenced the market with labels like "organic" and "natural." Manyflavor ingredients prepared by biotechnological methods have conqueredthe market recently and are destined to replace the ineective (.% pyrazinekg−biomass) extraction from plants or animal sources. This review focuseson the achievements and challenges in pyrazine synthesis. The major partdeals with an overview of methods such as the extraction of natural products,the chemical and biocatalytic synthesis, and fermentation by microorganisms.The dierent types of production are decisive for the declaration and valueof the final product and span from 200-3500 US Dollar/kg for the syntheticallyproduced or the naturally extracted 2,5-dimethylpyrazine, respectively.