Melatonin Synthesis in Fermented Foods

Melatonin (MEL) is a natural powerful antioxidant that may provide beneficial human health effects. Given that MEL is absorbed when melatonin-containing foods are eaten, the intake of these foods could maintain plasma melatonin concentration, which diminishes with age. Fermentation increases the MEL levels in foods and is considered a promising technological process by different sectors (consumers, industry, etc.). The formation of MEL and its isomers (IMs) occurs during controlled alcoholic fermentation of different foods. This is due to the action of microorganisms (yeasts and bacteria) and environmental stressors as elevated alcohol levels or lactic-acid production may naturally increase in these bioactive compounds. The possible enhancement of MEL and IMs in the fermented foods could improve their health benefits by increasing their blood levels in humans, thereby improving antioxidative defense mechanisms.