Effect of hot air treatments on senescence and quality parameters of harvested broccoli (Brassica oleracea L var Italica) heads

Abstract

Treatments with hot air were applied to broccoli (Brassica oleracea L) florets to investigate the effect on several quality and senescence parameters. To select the optimum treatment, florets were treated with different combinations of time/temperature ranging from 1 to 3 h and 37 to 50 • C and then placed in darkness at 20 • C. Most treatments delayed yellowing and loss of chlorophylls, except those performed at 37 • C, which accelerated senescence. Treatment at 48 • C for 3 h caused the highest delay in chlorophyll loss and was chosen to analyse its effect on quality and senescence. Non-treated florets showed yellowing and reduced their chlorophyll content during storage. Heat treatment delayed the onset of chlorophyll catabolism by 1 day and slowed down the rate of degradation. Treated florets also showed lower losses of total sugars and proteins and an inhibition of protein solubilisation. Control heads showed an increment in CO 2 production, which was not detected in heat-treated florets. Total antioxidants decreased and thiobarbituric acid-reactive substances (TBARS) increased during storage. The treatment delayed the decrease in antioxidant content and inhibited the increment in TBARS. In conclusion, treatment at 48 • C for 3 h delayed broccoli senescence at 20 • C and contributed to maintaining an overall better quality of the product.

Effect of time of day for harvest and postharvest treatments on the sugar metabolism of broccoli (Brassica oleracea var. italica)

“…Gas composition inside the bags was measured as indicated in Costa et al (2005). The same number of heads was coated with macro-perforated PVC film as a control.…”

“…In broccoli, these treatments have been effective in delaying senescence, causing a lower degradation of chlorophylls and allowing the storage for longer time (Costa et al 2006, Aiamla-or et al2010, Martínez-Hernández et al 2013. HT, can delay the onset of degradation of chlorophyll and slow down the senescence process (Funamoto et al 2002, Costa et al 2005. Also, broccoli treated with heat shows a lower loss of sucrose and proteins (Tian et al 1997, Costa et al 2005.…”

“…HT, can delay the onset of degradation of chlorophyll and slow down the senescence process (Funamoto et al 2002, Costa et al 2005. Also, broccoli treated with heat shows a lower loss of sucrose and proteins (Tian et al 1997, Costa et al 2005.…”

“…Considering that the rate of senescence of broccoli is related to the level of sugars (Costa et al 2005, Nishikawa et al 2005, Eason et al 2007), we proposed to study the effect of several treatments and the time of day at harvest on the content of sugars and the activity of enzymes involved in their metabolism: INV, SS and β-amylase during postharvest storage of broccoli.…”

Behaviour of fresh cut broccoli under different modified atmosphere conditions

“…29(3): 188-197 doi: 10.9755/ejfa.2016-07-907 http://www.ejfa.me/ Chaves, 2007), leek (Tsouvaltzis et al, 2006), melon (Luna Guzmán et al, 1999) and garlic (Cantwell et al, 2003). For broccoli, hot air or water can delay senescence in intact heads (Funamoto et al, 2002, Perini et al, 2017 and in fresh-cut product (Lemoine et al, 2008(Lemoine et al, , 2009Costa et al, 2005).…”