Thermal degradation lycopene

Kanasawud and Crouzet have studied the mechanism for formation of volatile compounds by thermal degradation of p-carotene and lycopene in aqueous medium (Kanasawud and Crouzet 1990a,b). Such a model system is considered by the authors to be representative of the conditions found during the treatment of vegetable products. In the case of lycopene, two of the compounds identified, 2-methyl-2-hepten-6-one and citral, have already been found in the volatile fraction of tomato and tomato products. New compounds have been identified 5-hexen-2-one, hexane-2,5-dione, and 6-methyl-3,5-heptadien-2-one, possibly formed from transient pseudoionone and geranyl acetate. According to the kinetics of their formation, the authors concluded that most of these products are formed mainly from all-(E) -lycopene and not (Z)-isomers of lycopene, which are also found as minor products in the reaction mixture. 

Kanasawud, P. and Crouzet, J.C. 1990. Mechanism of formation of volatile compounds by thermal degradation of carotenoids in aqueous medium. 2. Lycopene degradation. J. Agric. Food Chem. 38 1238-1242. 

Kanasawud [13] have proposed a mechanism for the formation of volatile compounds of saffron by thermal degradation of carotenoids including a-carotene (VI) and lycopene (VII) degradation. 

Shi and Le Maguer (2000) recently showed that the main causes of tomato lycopene degradation during processing are isomerization and oxidation. Thermal processing generally causes some loss of lycopene in tomato-based foods. In general, dehydrated and powdered tomatoes have poor lycopene... 

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