Inhibitory Effects of CaCl2 and Pectin Methylesterase on Fruit Softening of Raspberry during Cold Storage

Abstract

Quality of raspberry fruit experiences a rapid decline after harvest due to its vulnerable texture and high moisture content. Application of calcium chloride (CaCl2) combined with pectin methylesterase (PME) is efficient in delaying fruit softening. In this study, the effects of exogenous CaCl2 alone or in combination with PME on the structure of the cell wall, the molecular properties of pectin, and the amount of free water of raspberry during postharvest storage were investigated. The results showed that CaCl2 combined with PME treatment could maintain fruit firmness and inhibit weight loss. The treatment of CaCl2+PME maintained the cell wall structure via sustaining middle lamella integrity and reducing the activities of cell wall-degrading enzymes, such as polygalacturonase, pectin methylesterase, β-galactosidase, α-L-arabinofuranosidase, and β-xylosidase. In addition, CaCl2+PME treatment could effectively increase the content of chelate-soluble pectin (CSP) and develop a cross-linked structure between Ca2+ and CSP. Moreover, CaCl2+PME treatment was of benefit in maintaining free water content. CaCl2 in combination with PME treatment could be a promising method for inhibiting softening and maintaining the quality of postharvest raspberry during cold storage.

Arabidopsis root responses to salinity depend on pectin modification and cell wall sensing

“…S4A " type="url"/> ), we tested the effect of Ca 2+ on PME activity. We found that exogenous Ca 2+ not only inhibited PME activity, as it was previously reported in the fruits of tomato and raspberry plants ( Sobral et al, 2021 ; Yan et al, 2022 ) but also alleviated the salt-triggered activation of PME in vitro ( Fig. 4 B).…”

Arabinogalactan protein polysaccharide chains are required for normal biogenesis of plasmodesmata

“…Pectin is abundant in the middle lamella layer, which is responsible for cell adhesion and appears as a relatively high-electron density area in the cell wall in electron microscopic images. A positive correlation has been reported between the electron density of the middle lamellar region and the extent of calciummediated pectin crosslinking (Yan et al, 2022). In the hpgt1,2,3 triple mutant, the middle lamellar region was often not clearly recognized compared with the wild-type in electron microscopy, albeit an increase in pectin proportion in the cell wall was observed.…”

Effect of Chitosan/Thyme Oil Coating and UV-C on the Softening and Ripening of Postharvest Blueberry Fruits

“…Cold storage could effectively inhibit the decline of the blueberry cell wall crude extract and prolong the shelf life [ 28 ]. Yan et al stated that the storage quality of raspberries could be effectively improved by reducing the material loss of cell walls [ 29 ]. Sinha et al also reported that proper sample preservation could effectively inhibit cell wall metabolism in pears, maintain their structural integrity, and improve their storage quality [ 30 ] .…”