Gene regulation to increase acetaldehyde and diacetyl production by lactic acid bacteria

Lactic acid bacteria can produce flavor compounds,including alcohols,aldehydes and esters,among others,during fermentation.These bacteria also produce several organic acids,such as lactic acid,raw acetic acid,propionic acid,and others,during glycolysis.These organic acids can interact with flavor compounds to form unique flavors of fermented milk.Acetaldehyde and diacetyl have been recognized as important flavor components in yogurt.The present review article is focused on altering the acetaldehyde and diacetyl metabolic pathways as well as on increasing the production of these flavor compounds.The results of the studies conducted by domestic and foreign scholars on the regulation of the production of the acetaldehyde and diacetyl,as well as the synthesis pathways of these flavor compounds,are also summarized in the current paper.