Starch-based films for Red Torch ginger inflorescences postharvest conservation

Abstract

Different products have been tested to increase the vase life of cut flowers after harvest such as the biodegradable films. These products have been used in fruits since the application on the surface may provide the modification of the atmosphere around it, although, there is no information for flowers. The objective was to evaluate the effectiveness of cassava starch films as a postharvest product for Red Torch Ginger inflorescences. On the first experiment, different starch concentrations in the solution were tested and in the second experiment starch, concentrations with plasticizers and adjuvants were evaluated. The application of the biodegradable film in Red Torch stems acted as a barrier to the gases, as observed by their water absorption rate and the maintenance of fresh weight, maintaining postharvest quality up to Day 6. The visual quality was better in the inflorescences treated with 6% starch and in the films without additives. The use of 6% starch films led to lower contents of hydrogen peroxide and lipid peroxidation and higher levels of primary-metabolism macromolecules up to Day 6, delaying senescence and increasing postharvest durability. The addition of glycerol plasticizer to the different film concentrations improved the film resistance characteristics. It is recommended the use of films based on cassava starch at a concentration of 6%. The use of the adjuvant is not essential since it changed the film’s characteristics, leaving it less transparent and more viscous, hindering drying.

Meta-analysis of new technologies in post-harvest of tropical flowers

“…Thus, to ensure the quality and longevity of the stems, they must be harvested at closed or semi-open points (Araújo et al, 2018). Given these characteristics associated with the short vase life, it justifies the need and limitations related to new technologies to increase the postharvest longevity of this species (Nogueira et al, 2023) A similar result to the torch ginger also occurred for the alstroemeria, for which the use of technologies to increase vase life was also not significant (Figure 2). Alstroemeria is an herbaceous plant native to South America that has a long floral stem, with a great variety of flowers and spots on the petals.…”

“…Studies showed that this inflorescence, as a cut flower, provides an energy supply from the stem to the cell wall of the bract that stimulates its opening and strengthens the peduncle. During the opening of the inflorescence, there is degradation of cellulose in the involucral and floral bracts indicating the onset of the senescence process (Nogueira et al, 2023).…”

Exploring the impact of dry conditioning on the postharvest quality and longevity of torch ginger flower stems

“…Studies have shown that a high concentration of activity of these antioxidant enzymes is associated with greater post-harvest longevity in floral stems (Ren et al 2017). In contrast, Nogueira et al (2023) investigated the antioxidant system of floral stems from the torch ginger species cv "Red Torch" and observed the absence of expression of the SOD and CAT enzymes, which may justify the low post-harvest longevity of this species. However, the authors found that the peroxidase enzyme remained active during the senescence of post-harvest stems.…”

“…For the conditioning of torch ginger flower stems, it is recommended to harvest them early in the morning and promptly transport them for processing. Throughout this procedure, it is advisable to keep the stems immersed in water to maintain the hydration of the torch ginger (Nogueira et al 2023). The most common conditioning method from harvest to commercialization involves immersion in a solution.…”

Image-based approach for postharvest characterization of Red Torch inflorescences

“…Compared to the floral bracts, the involucral bracts of fully open inflorescences had a lower gloss level due to a longer period of exposure to the environment, while the floral bracts still have protection against this loss of gloss. This scenario can be explained by the natural production of carotenoids in larger amounts in involucral bracts as a way of protection against light incidence, and this process influences the production of reactive oxygen species, causing lipid peroxidation in these bracts and the loss of their gloss (Nogueira et al 2023).…”