1 Enzymatic browning

One of the most common and visible effects of enzymes on food is enzymatic browning, which occurs when polyphenols are oxidized by polyphenol oxidase (PPO) enzymes. This reaction produces brown pigments called melanins, which can enhance the flavor and appearance of some foods, such as coffee, tea, cocoa, and dried fruits. However, enzymatic browning can also cause undesirable changes in other foods, such as apples, potatoes, and avocados, which can turn brown and lose their freshness. Therefore, food producers often use methods to prevent or control enzymatic browning, such as adding antioxidants, lowering the pH, or reducing the oxygen exposure.

3 Enzymatic esterification

A third way that enzymes can create new flavors in food is by esterifying or combining alcohols and acids to form esters. Esters are volatile compounds that contribute to the fruity and floral aromas of many foods and beverages, such as wine, cider, and yogurt. Enzymes can catalyze the esterification reaction by either transferring an acyl group from one molecule to another (acyltransferases) or by condensing an alcohol and an acid (esterases). Enzymatic esterification can also modify the flavor of existing esters by changing their structure or composition.

4 Enzymatic isomerization

A fourth way that enzymes can create new flavors in food is by isomerizing or rearranging the atoms or groups of atoms within a molecule. This can result in different chemical and physical properties of the molecule, such as its shape, polarity, solubility, and reactivity. For example, isomerases can convert glucose into fructose, which is sweeter and more soluble than glucose. This can improve the sweetness and texture of foods, such as corn syrup, candy, and ice cream. Another example is epimerases, which can convert lactose into lactulose, which is a prebiotic that can stimulate the growth of beneficial bacteria in the gut.

5 Enzymatic cyclization

A fifth way that enzymes can create new flavors in food is by cyclizing or forming a ring structure from a linear molecule. This can alter the stability, reactivity, and aroma of the molecule, as well as its interaction with other molecules. For example, cyclases can convert geranyl pyrophosphate into limonene, which is a terpene that has a citrusy smell and flavor. This can enhance the flavor of foods, such as lemon, orange, and mint. Another example is lipoxygenases, which can convert linoleic acid into hexanal, which is an aldehyde that has a green and grassy smell and flavor. This can influence the flavor of foods, such as green tea, cucumber, and olive oil.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?