Role of carotenoid cleavage dioxygenases (CCDS) for the aroma formation in plants
Carotenoids are widely distributed whereas C40 isoprenoid pigments with polyene chains contain up to 15 conjugated double bonds. They furnish flowers and fruits with distinct colour (e.g., yellow, orange, and red), which can attract pollinators. Besides, carotenoids also have important role in human nutrition, especially some of carotenoids have an important function as Provitamin A activity. Specific enzymatic cleavage carotenoids by the act of carotenoid cleavage dioxygenases (CCDs) will produce various types of norisoprenoids. Several carotenoid derived aroma compounds or norisoprenoids are extremely powerful and also can act as beneficial substances for human health. World market volume for flavours and fragrance is high from year to year especially for aroma chemicals being produced by natural biocatalyst reaction like enzymatic cleavage carotenoids to produce natural norisoprenoids. This review will summarize information of the involvement of these enzymes in formation of carotenoid derived aroma compounds or norisoprenoids in several plants.
Carotenoids are widely distributed where C40 isoprenoid pigments with polyene chains contain up to 15 conjugated double bonds2. More than 700 naturally occurring carotenoids have been identified2. They furnish flowers and fruits with distinct colour (i.e., yellow, orange, and red), which attract pollinators, and play important roles in photosynthesis, light harvesting, and prevention of photooxidative damage (1). Carotenoids are compounds which have several conjugated double-bond structure. Thus, carotenoids undergo chemical and enzymatic reactions generating several compounds, which can have powerful aroma properties, i.e., carotenoids are precursors of norisoprenoids (2). These breakdown products of carotenoids are carbonyl compounds with 13, 11, 10 or 9 carbon atoms, and the terminal group of their carotenoid parent.
Specific enzymatic cleavage of carotenoids leads to the production of carotenoid derived aroma compounds which have an important role as flavour constituents. The C13 compounds are the most abundant carotenoid derived aroma compounds in nature. They can be divided into: (i) ...