β-Carotene Isomerization Kinetics during Thermal Treatments of Carrot Puree

Abstract

The effect of thermal processing on the stability of beta-carotene in carrot puree was investigated in a broad temperature range (80-150 degrees C). Heat induced changes in the stability of beta-carotene resulting in the conversion into its cis-isomers until an equilibrium state was reached after prolonged heating. By using nonlinear one-step regression analysis, the overall isomerization of all-trans-beta-carotene and the formation of individual cis-isomers could be modeled with a fractional conversion model. The Arrhenius equation was used to describe the temperature dependence of the reaction rate constants. As indicated by the low activation energies for all compounds (11 kJ mol(-1)), the isomerization rate constants showed little sensitivity toward the treatment temperature. The temperature dependence of the equilibrium concentration values after prolonged heating (C(f)) varied for the different compounds, but in all cases, a linear relation between the C(f) values and the treatment temperature could be noted. Although isomerization was observed as a result of thermal processing, it could be concluded that during industrially relevant heating processes, the retention of all-trans-beta-carotene in plain carrot puree was relatively high, which is most likely due to the presence of the protecting food matrix.

Degradation kinetics of carotenoids and visual colour in pumpkin (Cucurbita maxima L.) slices during microwave-vacuum drying

“…Several studies report the decrease of all-trans-carotenoid and the concomitant increase in cis-isomers in vegetables subjected to thermal processes. [35][36][37] Our results suggest that the β-carotene decreased, whereas three cisisomers (15-cis-β-carotene, 13-cis-β-carotene and 9-cis-β-carotene) increased on prolonging the heating time, which is accelerated at higher microwave power. Therefore, suitable kinetics for carotenoids degradation was evaluated at different drying conditions to minimize its loss during drying.…”

Carrot β-Carotene Degradation and Isomerization Kinetics during Thermal Processing in the Presence of Oil

“…It should be mentioned that a lot of different matrices, reaction media, and heating conditions were used in the different studies, which makes comparison of the obtained kinetic parameters difficult. In the kinetic study of Lemmens et al, 14 no oxidation was observed during thermal treatments of a carrot puree. The presence of oil, which is reported to act as a prooxidant, 21 can explain the observed differences between the carrot puree and the oil/carrot emulsion.…”

“…As a consequence of expressing the data as contributions, the same kinetic parameters for the isomerization of all-E-β-carotene and for the formation of the sum of Zisomers were found. In the kinetic study of Lemmens et al, 14 in which carrot puree was thermally treated in the absence of oil, the reaction rate constant for thermal isomerization of all-E-β-carotene was much lower (0.035 min −1 compared to 0.099 min −1 ). In other words, the presence of oil accelerates the isomerization of β-carotene in carrot puree.…”

α- and β-Carotene Stability During Storage of Microspheres Obtained from Spray-Dried Microencapsulation Technology

“…Carrot is widely known as an effi cient source of carotenoids, especially of α-and β-carotene [Marx et al, 2003;Lemmens et al, 2010]. Not only is β-carotene known for its dyeing properties, but also for its health effects as a vitamin A precursor [Liu et al, 2010;Ramoneda et al, 2011].…”