Thermal degradation orange juice

Phenolic compounds. Thermal degradation of various types of phenolic compounds has been shown to produce undesirable off-flavor compounds. Tatum et al. (4) identified 4-vinyl guaiacol as the most detrimental off-flavor compound in aged orange juice. When added to freshly expressed orange juice at a level of 0.075 ppm, it imparted an old fruit or rotten flavor. Substantial amounts of 4-vinyl guaiacol, from 0.6 to 1.6 ppm, were found in orange juice stored for 12 weeks at 35°C by Tatum et al. (6). 

M. C. Manso, F. A. R. Oliveira, J. C. Oliveira, and J. M. Friar, Modelling ascorbic acid thermal degradation and browning in orange juice under aerobic conditions, Int. J. Food Sci. Technol., 2001, 36, 303-312. 

Manso, M.C., Oliveira, F.A.R., Oliveira, J.C., and Frias, J.M. 2001b. Modelling ascorbic add thermal degradation and browning in orange juice Kinetics of pectinmethylesterase inactivation. J. Food Sci. 66, 328-331. 

Vikram, V.B., Ramesh, M.N., and Prapulla, S.G. 2005. Thermal degradation kinetics of nutrients in orange juice heated by electromagnetic and conventional methods. J. Food Eng. 69, 31-40. 

Anthocyanins are included in the list of natural compounds known to work as powerful antioxidants. Blood orange anthocyanins are not very stable during thermal treatment and storage they can degrade and form colorless or undesirable brown-colored compounds the juice loses its bright red color and gains a brown color (Maccarone et al, 1985). 

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