Investigating carotenoid loss after drying and storage of

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8. Study under controlled conditions
• There was also a linear relationship between !-carotene degradation rate and water
activity, and between !-carotene degradation rate and oxygen concentration. This
relationship requires further research but highlighted the straightforward influence of
these factors on carotenoid degradation. Oxygen (0-21%) with degradation constant
rates ranging between 0.0143-0.0887 day -1 has a far greater influence on carotenoid
degradation than water activity (0.13-0.76) with variations between 0.0332-0.0496
day -1 . Temperature (10-40ºC) has also an important influence on !-carotene
degradation with a range of 0.0024-0.0403 day -1 .
• Norisoprenoid formation (!-ionone; 5,6 epoxy-!-ionone; DHA) during storage of
dried OFSP chips was clearly related to the corresponding degradation of !-carotene.
The higher, the !-carotene degradation, the higher was the norisoprenoid formation.
At higher water activities, !-carotene was better preserved and lower concentrations
of volatiles were recorded. A similar observation was made at lower oxygen levels.
• With the identification of norisoprenoids products and their variation of
concentration during storage, a potential pathway of degradation was proposed. This
pathway could be investigated using statistical prediction tools to predict the
concentration of norisoprenoid compounds during storage. Further research is
required to understand nature of the intermediate compounds between !-carotene and
norisoprenoids formed during storage and the kinetics of their formation and
degradation.