Longevity and alleviation of chilling injury in heliconia cut flowers coated with carnauba wax nanoemulsion and sorbitol pulsing solution

Heliconias are tropical flowers with significant ornamental and economic potential, due to their wide variety of colors and shapes. However, they are highly perishable due to excessive transpiration (water loss), stem bending, and sensitivity to chilling injury (CI) when stored at low temperatures. In this study, the combined effect of sorbitol (5 %) in a pulsating solution and a coating with carnauba wax nanoemulsion (3 % CWN) on the longevity and control of CI under refrigerated conditions (8 °C) and after transfer to room temperature (28 °C) was evaluated. The combined application of 5 % sorbitol in the pulsating solution and 3 % CWN on the bracts inhibited and alleviated CI symptoms both under refrigerated and room temperature, resulting in greater bract longevity. Under these conditions, the absence or reduction of CI symptoms was associated with a lower accumulation of oxidative stress indicators (electrolyte leakage, malondialdehyde – MDA and hydrogen peroxide – H 2 O 2 ), preservation of antioxidant compounds (total polyphenols and carotenoids) and an increase in enzymatic activities (superoxide dismutase – SOD and catalase – CAT). These results indicate that these variables, together, contributed to preventing and mitigating oxidative damage resulting from CI in the bracts. It is concluded that the strategy of combining 5 % sorbitol and 3 % CWN constitutes a promising approach for conditioning heliconia flower stems at low temperatures (8 °C), as it attenuates CI and prolongs postharvest shelf life. Schematic representation : Schematic representation: The combined effect of 5 % sorbitol in pulsing solution with the carnauba wax nanoemulsion coating (3 %), CWN acted by reducing/inhibiting the occurrence of cold injury, resulting in less accumulation of malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ) and better preservation of the cell membrane that preserved the non-enzymatic antioxidant compounds (polyphenols, carotenoids), enzymatic (SOD and CAT) and the visual quality of the heliconia flower stems during refrigerated storage and transfer to the environment. • The combination of 5 % sorbitol with 3 % carnauba wax nanoemulsion significantly reduced the symptoms of chilling injury in heliconias stored at 8 °C. • The integrated treatment preserved the integrity of cell membranes, with lower levels of hydrogen peroxide, malondialdehyde and electrolyte leakage. • The combined use of sorbitol and carnauba wax maintained the levels of antioxidant compounds and increased the antioxidant enzymes activity (SOD and CAT), delaying senescence.