Changes in fruit firmness, quality traits and cell wall constituents of two highbush blueberries (Vaccinium corymbosum L.) during postharvest cold storage

Given their attractive appearance and flavour, as well as high antioxidant content, Vaccinium corymbosum L. fruits are greatly appreciated by consumers. These quality traits are primarily dependent on pomological characteristics of the cultivar. Vaccinium corymbosum ‘Bluecrop’ is one of the most popular and valuable cultivars of highbush blueberry; however, its fruits become soft shortly after harvesting. Changes in the fruit structure and in the content of phenolic compounds and, in particular, emergence of some traits related to fruit firmness and shelf life, were analysed in the surface layers of ‘Bluecrop’ fruits from the stage of flowering through the fruit set stage to harvest maturity using light microscopy, transmission electron microscopy, and scanning electron microscopy. The study involved investigations of qualitative and quantitative changes in the development and microstructure of epicuticular wax, cuticle, epidermis, hypodermis, and stone cells, and analysis of the presence of tannins and anthocyanins. Moreover, it was found that the development of many traits associated with fruit firmness and shelf life started in the initial period of ontogeny. These results can be useful for the researchers developing new cultivars in detection of early manifestations of developmental features of specific quality traits and in comparative analyses of blueberry cultivars differing in fruit firmness and shelf life.

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Cell Wall Calcium and Hemicellulose Have a Role in the Fruit Firmness during Storage of Blueberry (Vaccinium spp.)

Plants ◽

10.3390/plants10030553 ◽

2021 ◽

Vol 10 (3) ◽

pp. 553

Author(s):

Patricio Olmedo ◽

Baltasar Zepeda ◽

Bárbara Rojas ◽

Christian Silva-Sanzana ◽

Joaquín Delgado-Rioseco ◽

...

Keyword(s):

Cell Wall ◽

Cold Storage ◽

Calcium Binding ◽

High Performance ◽

Calcium Concentration ◽

Anion Exchange Chromatography ◽

Exchange Chromatography ◽

Fruit Firmness ◽

Cell Wall Components ◽

Wall Components

The firmness of blueberry is one of its most significant quality attributes. Modifications in the composition of the cell wall have been associated with changes in the fruit firmness. In this work, cell wall components and calcium concentration in two blueberry cultivars with contrasting firmness phenotypes were evaluated at harvest and 30 days cold storage (0 °C). High performance anion-exchange chromatography with pulse amperometric detector (HPAEC-PAD) analysis was performed using the “Emerald” (firmer) and “Jewel” (softer) blueberry cultivars, showing increased glucose in the firmer cultivar after cold storage. Moreover, the LM15 antibody, which recognizes xyloglucan domains, displayed an increased signal in the Emerald cultivar after 30 d cold storage. Additionally, the antibody 2F4, recognizing a homogalacturonan calcium-binding domain, showed a greater signal in the firmer Emerald blueberries, which correlates with a higher calcium concentration in the cell wall. These findings suggest that xyloglucan metabolism and a higher concentration of cell wall calcium influenced the firmness of the blueberry fruit. These results open new perspectives regarding the role of cell wall components as xyloglucans and calcium in blueberry firmness.

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Transcriptomic and Metabolic Analyses Reveal the Mechanism of Ethylene Production in Stony Hard Peach Fruit during Cold Storage

International Journal of Molecular Sciences ◽

10.3390/ijms222111308 ◽

2021 ◽

Vol 22 (21) ◽

pp. 11308

Author(s):

Yan Wang ◽

Li Deng ◽

Junren Meng ◽

Liang Niu ◽

Lei Pan ◽

...

Keyword(s):

Cell Wall ◽

Low Temperature ◽

Cold Storage ◽

Ethylene Production ◽

Ethylene Biosynthesis ◽

Expression Level ◽

Fruit Firmness ◽

Peach Fruit ◽

Stony Hard

Stony hard (SH) peach (Prunus persica L. Batsch) fruit does not release ethylene and has very firm and crisp flesh at ripening, both on- and off-tree. Long-term cold storage can induce ethylene production and a serious risk of chilling injury in SH peach fruit; however, the regulatory mechanism underlying ethylene production in stony hard peach is relatively unclear. In this study, we analyzed the phytohormone levels, fruit firmness, transcriptome, and lipidome changes in SH peach ‘Zhongtao 9’ (CP9) during cold storage (4 °C). The expression level of the ethylene biosynthesis gene PpACS1 and the content of ethylene in SH peach fruit were found to be upregulated during cold storage. A peak in ABA release was observed before the release of ethylene and the genes involved in ABA biosynthesis and degradation, such as zeaxanthin epoxidase (ZEP) and 8’-hydroxylase (CYP707A) genes, were specifically induced in response to low temperatures. Fruit firmness decreased fairly slowly during the first 20 d of refrigeration, followed by a sharp decline. Furthermore, the expression level of genes encoding cell wall metabolic enzymes, such as polygalacturonase, pectin methylesterase, expansin, galactosidase, and β-galactosidase, were upregulated only upon refrigeration, as correlated with the decrease in fruit firmness. Lipids belonging to 23 sub-classes underwent differential rearrangement during cold storage, especially ceramide (Cer), monoglycosylceramide (CerG1), phosphatidic acid (PA), and diacyglyceride (DG), which may eventually lead to ethylene production. Exogenous PC treatment provoked a higher rate of ethylene production. We suspected that the abnormal metabolism of ABA and cell membrane lipids promotes the production of ethylene under low temperature conditions, causing the fruit to soften. In addition, ERF transcription factors also play an important role in regulating lipid, hormone, and cell wall metabolism during long-term cold storage. Overall, the results of this study give us a deeper understanding of the molecular mechanism of ethylene biosynthesis during the postharvest storage of SH peach fruit under low-temperature conditions.

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539 Firmness of Blueberry Fruit Following Storage in Air or Controlled Atmospheres

HortScience ◽

10.21273/hortsci.34.3.538f ◽

1999 ◽

Vol 34 (3) ◽

pp. 538F-539 ◽

Cited By ~ 1

Author(s):

Charles F. Forney ◽

Kumudini U.K.G. Nicholas ◽

Michael A. Jordan

Keyword(s):

Storage Time ◽

Vaccinium Corymbosum ◽

Fruit Firmness ◽

Factors Affecting ◽

Controlled Atmospheres ◽

Initial Values ◽

Fruit Decay ◽

Highbush Blueberries

Factors affecting the firmness of `Burlington', `Coville', and `Jersey' highbush blueberries (Vaccinium corymbosum L.) during storage in controlled atmospheres or air were characterized. Fruit were stored for up to 9 weeks in 6-ounce plastic clamshells at 0 or 3 °C. Fruit firmness was measured as grams per millimeter of fruit deformation using a FirmTech1 firmness tester (Bioworks, Stillwater, Okla.). Blueberry fruit held in sealed chambers in 0% CO2/15% O2 did not soften during storage. At 0 and 3 °C, fruit firmness of all cultivars increased an average of 30% after 9 weeks of storage. Changes in fruit firmness varied between cultivars and ranged from no change in `Coville' fruit held at 3 °C to an increase in firmness of 9 g·mm–1 per week in `Burlington' fruit held at 3 °C. CO2 inhibited the postharvest firming of blueberry fruit and at higher concentrations induced softening. At 0 °C, fruit firmness decreased below initial values when held in concentrations of CO2 >12% for `Burlington' and >10% for `Coville' and `Jersey'. At 3 °C, fruit were more tolerant to CO2 and softening occurred at CO2 concentration >17% for `Burlington', and >12% for `Coville' and `Jersey' fruit. CO2-induced softening was enhanced by increased storage time. CO2 also was effective in reducing fruit decay. After 9 weeks, 2% and 36% of fruit held in air at 0 and 3 °C, respectively, were decayed. However, all fruit held in 10 to 25% CO2 had <1% decay. Controlled atmospheres of 10% to 15% CO2 reduced decay while maintaining fruit firmness.

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(198) Common Strategies to Manipulate Pre- and Postharvest Ripening of Fruit Fail with Pawpaw

HortScience ◽

10.21273/hortsci.41.4.1051a ◽

2006 ◽

Vol 41 (4) ◽

pp. 1051A-1051

Author(s):

Federica Galli ◽

Rumphan Koslanund ◽

Douglas D. Archbold ◽

Kirk W. Pomper

Keyword(s):

Heat Treatment ◽

Cold Storage ◽

Treatment Strategies ◽

Quality Traits ◽

Fruit Firmness ◽

Rapid Loss ◽

Asimina Triloba ◽

Heat Treated ◽

Postharvest Ripening ◽

Storage Temperatures

Ripening pawpaw [Asimina triloba (L.) Dunal] fruit exhibit climacteric peaks of ethylene and CO2 production 48 to 72 hours after harvest, and thus may be considered climacteric. The development of desirable quality traits and the loss of fruit firmness during ripening is extremely rapid, and a variety of strategies to slow these processes via manipulation of ethylene production and/or response and by more direct techniques like postharvest heat treatment have been attempted. Fruit, branches with fruit, and/or whole trees have been sprayed with ethephon or aminoethoxyvinylglycine to hasten or delay ripening, respectively. After harvest, fruit have been treated with commercial and higher rates of 1-methylcyclopropene for various durations at ambient and cold storage temperatures. Fruit have also been heat-treated at various temperatures, using both brief “shock” treatments above 40 °C and longer periods at 35 °C to 40 °C. In addition, in an attempt to alleviate the loss of ripening capacity as well as the development of injury symptoms from cold storage for longer than 4 weeks, cold-stored fruit were warmed to ambient temperature intermittently and then returned to cold storage. While some effects of the treatments were noted, the responses to all of these treatment strategies have failed to appreciably alter fruit ripening, the rapid loss of firmness, or otherwise maintain fruit quality beyond that without treatment.

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