Investigating carotenoid loss after drying and storage of

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8. Study under controlled conditions
• d(β-carotene)/dt = - k1β-carotene
• d(13-cis-β-carotene)/dt = k1β-carotene - k1’13-cis β-carotene
• d(β-carotene-5,8-epoxide)/dt = k2β-carotene - k2’β-carotene-5.8-epoxide
• d(unidentified-β-carotene-epoxide)/dt = k3β-carotene – k3’unidentifiedβcarotene-epoxide
• d(β-apo-8’-carotenal)/dt = k4β-carotene
• d(β-cyclocitral)/dt = k4β-carotene - k4’β-cyclocitral
• d(β-apo-10’-carotenal)/dt = k5β-carotene
• d(β-ionone)/dt = k5β-carotene – k6β-ionone
• d(5,6epoxy-β-ionone)/dt = k6β-ionone – k75,6epoxy-β-ionone
• d(DHA)/dt = k75,6epoxy-β-ionone – k7’DHA
(Equation 8-5)
Molar Balance
5 mol β-carotene 1 mol 13-cis-β-carotene
+ 3 mol O2 1 mol β-carotene-5.8-epoxide
1 mol unidentified β-carotene
1 mol β-apo-10’-carotenal
1 mol β-apo-8’-carotenal
1 mol β-ionone
1 mol β-cyclocitral
1 mol β-ionone + 1/2 mol O2 1 mol 5,6-epoxy-β-ionone
1 mol 5,6-epoxy-β-ionone 1 mol DHA
In order to achieve a full mathematical modelling of the degradation of carotenoids in a
food product, these equations should be solved. However this study has not been
undertaken as part of this research work.
8.4 CONCLUSION
This study used a storage system to describe the degradation of !-carotene under
controlled conditions of temperature, water activity and oxygen.
• The Arrhenius and Eyring models correctly described the carotenoid degradation in
dried stored sweet potato between 10 and 40ºC. The Arrhenius model was validated
using samples stored at room temperature in the UK and in Uganda (non-isotherm
conditions). This model successfully predicted !-carotene degradation using
temperature data and could be used in field applications.