Thermal and pressure-temperature degradation of chlorophyll in broccoli (Brassica oleracea L. italica) juice: a kinetic study
1998
Loey, A van | Ooms, V. | Weemaes, C. | Broeck, I. van den | Ludikhuyze, L. | Indrawati. | Denys, S. | Hendrickx, M.
Heat and combined pressure-temperature degradation of chlorophyll in broccoli juice have been studied on a kinetic basis. A treatment at 100 degrees C and atmospheric pressure during 37 min resulted in a 90% decrease in total chlorophyll content of broccoli juice. An extreme pressure stability of both chlorophylls a and b at room temperature was observed. Significant reductions in chlorophyll content were noticed only when pressure was combined with temperatures exceeding 50 degrees C. Chlorophyll degradation reactions at atmospheric as well as at elevated pressures could be adequately described by assuming a first-order decay. Chlorophyll a degradation occurred more rapidly as compared to chlorophyll b degradation under all pressure-temperature combinations tested (1 - 800 MPa/50 - 120 degrees C). Degradation rates increased with temperature according to the Arrhenius law at all pressures tested.
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