Most artificial flavors are specific and often complex mixtures of singular naturally occurring flavor compounds combined to either imitate or enhance a natural flavor. These mixtures are formulated by flavorists to give a food product a unique flavor and to maintain flavor consistency between different product batches or after recipe changes. The list of known flavoring agents includes thousands of molecular compounds, and flavor chemists (
flavorists) can often mix these together to produce many of the common flavors. Many flavorings consist of
esters, which are often described as being sweet or fruity. The compounds used to produce artificial flavors are almost identical to those that occur naturally. It has been suggested that artificial flavors may be safer to consume than natural flavors due to the standards of purity and mixture consistency that are enforced either by the company or by law. Natural flavors, in contrast, may contain impurities from their sources, while artificial flavors are typically more pure and are required to undergo more testing before being sold for consumption. The number of food smells is unbounded; a food's flavor, therefore, can be easily altered by changing its smell while keeping its taste similar. This is exemplified in artificially flavored
jellies,
soft drinks and candies, which, while made of bases with a similar taste, have dramatically different flavors due to the use of different scents or fragrances. Most flavors represent a mixture of
aroma compounds, the raw material that is produced by flavor companies. In rare cases, a single synthetic compound is used in pure form. Artificial
vanilla flavors
vanillin and
ethylvanillin are a notable exception, as well as the artificial
strawberry flavor (
ethyl methylphenylglycidate). The ubiquitous "green apple" aroma is based on
hexyl acetate. Some flavors are relatively multifaceted. For example, the basic aroma of cooked meat is formed by a combination of
Maillard reaction,
lipid peroxidation, and degradation of sulfur-containing compounds, such as
thiamine and cysteine. With this understanding, an artificial chicken flavor can be made from ingredients as simple as glucose, salt, cysteine, and
arachidonic acid: when heated in a water solution they undergo these three reactions to produce the desired flavor. (Such a flavor produced during the preparation process from precursor compounds is called a "process flavor"). Small tweaks to the mixture can instead produce a beef flavor. This kind of basic meat flavoring has been known since the 1970s. Of course, these four chemicals only mimic a small number of possible reactions out of the many reactions possible among the complex flavor precursor chemicals found in meat. For a more realistically complex aroma, natural feedstocks such as
yeast extract,
hydrolyzed vegetable protein, and spices can be used to expand the number of possible reactions. They also contribute peptides, free amino acids, and nucleic acid metabolites that all play a role in the natural taste of meat. ==Determination==