Ethanol vapor treatment of ‘Laetitia’ plums stored under modified atmosphere

Abstract

The objective of this work was to evaluate the effect of ethanol vapor during storage in modified atmosphere on the ripening and maintenance of the postharvest quality of ‘Laetitia’ plums. The plums were obtained from an orchard in the municipality of Lages, SC. The experimental design adopted was completely randomized. The treatments evaluated were ethanol vapor doses (0, 2, 4, 6 and 8 mL kg-1 of fruit). The fruits were stored at 0.5±0.2°C and 92±2% RH for 30 days. Upon their removal from storage followed by another three days in room conditions (20±5ºC and 63±2% RH), the fruits were evaluated in relation to their physical and chemical attributes, incidence and intensity of internal browning, quantification of ethanol, acetaldehyde and ethyl acetate, and the activity of enzymes peroxidase and superoxide dismutase. The application of ethanol vapor was efficient in maintaining the fruits flesh firmness, reducing the evolution of the red coloring, and resulted in greater activity of enzymes peroxidase and superoxide dismutase. However, the doses evaluated were not efficient in reducing the internal browning.

Ethanol vapor, initial low O 2 , and high CO 2 stresses in the storage of Laetitia Plums

“…Plums treated with ethanol vapor (0.5 and 1.5%) and ILOS shows higher flesh firmness values after 20CS + 4SL and 30CS + 4SL (Table 2). Delays in flesh firmness reduction was also observed in tomatoes and melons (Jin et al., 2013; Tzortzakis & Economakis, 2007) and “Laetitia” plums (De Martin et al., 2018; Nunes et al., 2019) subjected to ethanol vapor. Jin et al.…”

“…(2018) and Nunes et al. (2019), no difference between ethanol vapor and control treatments to TA and SS in “Laetitia” plums. Soluble sugars and organic acids are substrates of the respiratory process.…”

“…However, the application of 1.5% ethanol vapor resulted in less change in peel color (Table 2). Other research has also observed a positive effect of ethanol vapor on delaying the color evolution of “Laetitia” plums (De Martin et al, 2018; Nunes et al., 2019). The maintenance of peel color in fruit with these treatments occurs due to less ethylene biosynthesis and action, since fruit color changing in plums during ripening is a process dependent on the action of this phytohormone (Candan et al, 2006; Candan et al., 2011).…”

“…(2009), ethanol vapor inhibited the production of ethylene in broccoli due to a strong reduction in the activity of the enzymes ACC‐synthase and ACC‐oxidase. Moreover, the ethanol vapor also reduced the ethylene production rate in “Yumeiren” melons (Jin et al., 2013) and “Laetitia” plums (De Martin et al., 2018; Nunes et al., 2019). The alcohol reduced the expression of the genes BO‐ACO1, BO‐ACO2, and BO‐ACS1 in broccoli (Asodaet al, 2009), and CM‐ACO1, CM‐ACO2, CM‐ACO3, CM‐ACS1, CM‐ACS2, and CM‐ACS3 in melon (Jin et al., 2013).…”

“…Effect of ethanol vapor treatment on the respiration rate in “Laetitia” plums has been controversial. Positive effects were observed with 3.5 ml of ethanol kg −1 fruit (De Martin et al., 2018) of ethanol, however, not with 2 to 8 ml of ethanol kg −1 fruit (Nunes et al., 2019).…”