UV-C treatment delays postharvest senescence in broccoli florets

COSTA, L., VICENTE, A.R., CIVELLO, P.M., CHAVES, A.R., MARTIÌNEZ, G.A

POSTHARVEST BIOLOGY AND TECHNOLOGY

Elsevier

Lugar: Amsterdam; Año: 2006 vol. 39 p. 204 - 210

0925-5214

Abstract Central broccoli heads (cv. de Cicco) were harvested and treated with UV-C light (4, 7, 10, or 14 kJm−2). All treatments delayed yellowing and chlorophyll degradation at 20 ◦C but the irradiation dose of 10 kJm−2 allowed retaining the highest chlorophyll content yet had lower amounts of pheophytins than every treatment other than 7 kJm−2. This dose was selected to analyze the effect of UV-C on postharvest broccoli senescence at 20 ◦C. The UV-C treatment delayed yellowing, chlorophyll a and b degradation, and also the increase in pheophytins during storage. The activity of chlorophyll peroxidase and chlorophyllase was lower in UV-C treated broccoli. Instead, Mg-dechelatase activity increased immediately after the treatment, but after 4 and 6 d this activity was lower in UV-C treated florets than in controls. Treated broccoli also displayed lower respiration rate, total phenols and flavonoids, along with higher antioxidant capacity. The results suggest that UV-C treatments could be a useful non-chemical method to delay chlorophyll degradation, reduce tissue damage and disruption, and maintain antioxidant capacity in broccoli.−2). All treatments delayed yellowing and chlorophyll degradation at 20 ◦C but the irradiation dose of 10 kJm−2 allowed retaining the highest chlorophyll content yet had lower amounts of pheophytins than every treatment other than 7 kJm−2. This dose was selected to analyze the effect of UV-C on postharvest broccoli senescence at 20 ◦C. The UV-C treatment delayed yellowing, chlorophyll a and b degradation, and also the increase in pheophytins during storage. The activity of chlorophyll peroxidase and chlorophyllase was lower in UV-C treated broccoli. Instead, Mg-dechelatase activity increased immediately after the treatment, but after 4 and 6 d this activity was lower in UV-C treated florets than in controls. Treated broccoli also displayed lower respiration rate, total phenols and flavonoids, along with higher antioxidant capacity. The results suggest that UV-C treatments could be a useful non-chemical method to delay chlorophyll degradation, reduce tissue damage and disruption, and maintain antioxidant capacity in broccoli.◦C but the irradiation dose of 10 kJm−2 allowed retaining the highest chlorophyll content yet had lower amounts of pheophytins than every treatment other than 7 kJm−2. This dose was selected to analyze the effect of UV-C on postharvest broccoli senescence at 20 ◦C. The UV-C treatment delayed yellowing, chlorophyll a and b degradation, and also the increase in pheophytins during storage. The activity of chlorophyll peroxidase and chlorophyllase was lower in UV-C treated broccoli. Instead, Mg-dechelatase activity increased immediately after the treatment, but after 4 and 6 d this activity was lower in UV-C treated florets than in controls. Treated broccoli also displayed lower respiration rate, total phenols and flavonoids, along with higher antioxidant capacity. The results suggest that UV-C treatments could be a useful non-chemical method to delay chlorophyll degradation, reduce tissue damage and disruption, and maintain antioxidant capacity in broccoli.−2. This dose was selected to analyze the effect of UV-C on postharvest broccoli senescence at 20 ◦C. The UV-C treatment delayed yellowing, chlorophyll a and b degradation, and also the increase in pheophytins during storage. The activity of chlorophyll peroxidase and chlorophyllase was lower in UV-C treated broccoli. Instead, Mg-dechelatase activity increased immediately after the treatment, but after 4 and 6 d this activity was lower in UV-C treated florets than in controls. Treated broccoli also displayed lower respiration rate, total phenols and flavonoids, along with higher antioxidant capacity. The results suggest that UV-C treatments could be a useful non-chemical method to delay chlorophyll degradation, reduce tissue damage and disruption, and maintain antioxidant capacity in broccoli.◦C. The UV-C treatment delayed yellowing, chlorophyll a and b degradation, and also the increase in pheophytins during storage. The activity of chlorophyll peroxidase and chlorophyllase was lower in UV-C treated broccoli. Instead, Mg-dechelatase activity increased immediately after the treatment, but after 4 and 6 d this activity was lower in UV-C treated florets than in controls. Treated broccoli also displayed lower respiration rate, total phenols and flavonoids, along with higher antioxidant capacity. The results suggest that UV-C treatments could be a useful non-chemical method to delay chlorophyll degradation, reduce tissue damage and disruption, and maintain antioxidant capacity in broccoli. 12 13 14 15 16 17 18 19 20 21 © 2005 Published by Elsevier B.V.© 2005 Published by Elsevier B.V.