Thermal and Pressure−Temperature Degradation of Chlorophyll in Broccoli (Brassica oleraceaL.italica) Juice:  A Kinetic Study

Abstract

Heat and combined pressure-temperature degradation of chlorophyll in broccoli juice have been studied on a kinetic basis. A treatment at 100 °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 °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 °C). Degradation rates increased with temperature according to the Arrhenius law at all pressures tested.

Effect of high pressure processing on microbiological and physical qualities of carrot and spinach

“…Less negative impact on color was observed in the HP-treated samples when compared to the controls. This suggests that pigments such as β-carotene, chlorophyll a, and chlorophyll b are relatively stable under pressure treatment, which can improve the color retention of carrot and spinach leaves (11,22,23). Although the color changes in HPP-treated samples were less than those in the cooked samples, the color differences in carrot and spinach leaves were gradually increased with increasing pressure level and process time.…”

Rosemary and Pitanga Aqueous Leaf Extracts On Beef Patties Stability under Cold Storage

“…Adversely, attention must be drawn to the lower red intensity (a*) of Pitanga extracts, which may have been influenced by the chlorophyll content of this species' dried leaves, and for its lower pH value. Even though these green pigments are greatly degraded with thermal process 23 , the superior total chlorophyll content of Pitanga leaves may have contributed for this difference in extracts color.…”

Influence of high hydrostatic pressure on quality parameters and structural properties of aloe vera gel (Aloe barbadensis Miller)

“…This phenomenon is probably the cause of the initially more intense bright green colour on the surface of the HHP-treated beans. Van Loey et al (1998) studied the effects of pressure and temperature on chlorophyll degradation in a broccoli-extract. They also found significant reduction of chlorophyll when pressure was combined with temperatures higher than 50°C.…”

“…Negative effects on the colour after HHP treatment were probably caused by residual activity of enzymes such as lipoxygenase, peroxidase or chlorophyllase. Effects of storage on green colour after pressurization have been studied, but only in purées and extracts of guacamole (Palou et al 2000;Sohn and Lee 1998;Van Loey et al 1998). They have also observed decreases in greenness during storage.…”