The spice and fragrance industry originated in Europe, the spices produced in Paris and Grasse in France, and the edible flavors in the Netherlands. The reputation of the flavors produced in the UK is very high. After World War II, the United States and Japan jointly operated flavors and fragrances to catch up with Europe at an alarming rate. At present, Europe, the United States, and Japan have formed the world's most advanced industrial center for spices and fragrances, and the development of natural and synthetic fragrances with fragrances as the leading products. China's edible flavor and fragrance industry presents a fierce competition between foreign-funded enterprises and private enterprises.

Most of the compounds with aroma are low molecular organic compounds. Commonly used are aldehydes, ketones, carboxylic acids, esters, alcohols, ethers, and the like. Among these compounds, there are aliphatic compounds, alicyclic compounds, aromatic compounds, and heterocyclic compounds. In particular, the research and application of heterocyclic compounds is a new field that has been developed in recent years.

Heterocyclic compounds are present in very small amounts in the aroma mixture, and are commonly used are pyrazines, furans, pyrroles, thiazoles, pyridines and azoles. Among the fused ring systems, cyclopentazines and benzothiazoles are the most common. Some heterocyclic compounds have very high aroma strength and a very low aroma threshold, with a minimum of 0.002 g/kg. Therefore, as a special-effect aroma compound, it is an ideal ingredient for food flavor additives.

Of the approximately 1040 monomeric fragrances reviewed by FEMA before 1975 (the variety of natural raw materials removed in FEMA 2001-3444), 170 sulfur-containing nitrogen-containing heterocyclic perfumes, approximately 16%. However, among the 615 monomeric fragrances released after 1975 (the varieties of FEMA3445~4068 with the removal of natural raw materials), more than 200 kinds of heterocyclic perfumes, accounting for about 32%. In addition, there are a large number of varieties of reaction fragrances with different aromas and flavors, which are also widely used in food flavors.

Advances in the development of fragrances have included the discovery and understanding of aroma characteristic compounds. As for these characteristic aroma compounds, whether aliphatic or heterocyclic, the source is nothing more than these two routes:

The first is the enzymatic process and biological processes, such as alcoholic beverages, the aroma of dairy products, and scallions. The processes involved in each specific food product are complex and varied. The second is the non-enzymatic process. For example, during the heat treatment of steaming and roasting, the flavor of meat, coffee and nuts is formed, and the non-enzymatic process plays an important role. There are also cases where both routes work, such as the formation of bread aroma - therefore, the characteristic aroma of the food is derived from the inherent precursor of the food, the different aroma compounds formed as the manufacturing technique changes.