Impact of Electrostatic Atomized Water Particles Treatment on Chlorophyll Degradation and Delay Ripening in a Thai Banana (Musa × paradisiaca, cv. ‘Namwa’ Banana) during Storage

Electrostatic atomized water particles (EAWPs) treatment was applied to investigate its effect on chlorophyll (Chl) degradation and ripening delay in ‘Namwa’ bananas. Banana fruits were pretreated with EAWPs generated from a device (Panasonic F-GMK01) for 0 (control), 0.5, 1.0, 1.5, and 3.0 h in a closed 50 L container, and then kept in perforated polypropylene plastic bags and stored at ambient temperature (25 ± 2°C) under dark conditions. The results showed that 1.0 h-EAWPs treatment best retained peel greenness with a significantly higher hue angle and lower L* value than other treatments on day 6. Also, the 1.0 h-EAWPs treatment maintained the total Chl content, firmness, total soluble solids (TSS), and delayed the ripening index (RI) of fruit accompanied by a delayed climacteric rise in ethylene and respiration rate compared to the control. It was found that the 1.0 h-EAWP treatment induced accumulations of nitric oxide (NO) in peel tissues and suppressed the activities of Chl-degrading enzymes (chlorophyllase, Mg-dechelatase, Chl-degrading peroxidase, and pheophytinase) in the peel. Furthermore, Chl derivatives levels (chlorophyllide a, pheophobide a, 13²-hydroxychlorophyll a, and pheophytin a) were higher in fruits treated with EAWPs than the control fruits. The results suggest that EAWPs technology could be an alternative approach to delay Chl degradation and ripening in ‘Namwa’ bananas.