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Apples And Pears Contain Pathways To 'Breathe'

Date:
July 14, 2008
Source:
European Synchrotron Radiation Facility
Summary:
Pears and apples contain air pathways to "breathe." The pathways are microscopic structures for oxygen supply and are key in determining the fruit's health. Researchers have visualized these pathways for the first time, therefore proving their hypothesized existence. The results allow a better understanding of how fruit degrades after harvest and provide a scientific explanation of the everyday experience that pears are more susceptible to decay during storage.
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Pears and apples contain air pathways to “breathe”.
Credit: P. Verboven/Image courtesy of European Synchrotron Radiation Facility

Pears and apples contain air pathways to “breathe”. The pathways are microscopically small structures for oxygen supply and are key elements in determining the fruit’s health. Researchers from the Catholic University of Leuven in Belgium and the European Synchrotron Radiation Facility (ESRF) have visualized them for the first time, therefore proving their hypothesized existence.

In apples, the pathways appear as irregular cavities between cells, whilst in pears they have the shape of tiny interconnected channels. These results allow a better understanding of how the fruit degrades after harvest and provide a scientific explanation of the everyday experience that pears are more susceptible to decay during storage.

Apples and pears continue to “breathe” after picking. To keep the fruit healthy, a minimum level of oxygen must be supplied to all cells of the fruit. If this does not happen, internal browning disorders appear and fruit quality decreases. 

The correct oxygen concentration is related to the complex mechanisms of gas exchange, respiration and fermentation in the fruit. Restricted gas exchange leads to too low a level of oxygen inside the cells. Three-dimensional images of the fruit microstructure help to determine and explain gas exchange rates and when fruit cells start to die and browning initiates. Such imaging is not easy as fruit contains a lot of water and the resolution and contrast of conventional medical 3-D scanners is insufficient.

The Leuven team used the European Synchrotron Radiation Facility in Grenoble to perform tomographic imaging of fruit samples. As the researchers report in the recent issue of Plant Physiology, the powerful equipment produces 3-D images that are accurate down to and below 1/1000 of a millimeter, with sufficient contrast to separate out void spaces from cells. The images are now used in computer models to calculate oxygen concentration in individual cells of fruit tissues.

“It is still unclear how airways in the fruit develop, and why apples have cavity structures and pears micro-channel networks”, explains Pieter Verboven, from the Catholic University of Leuven and corresponding author of the paper. However, the results do help explain why pears are so prone to decay during storage: “The micro-channels are so small that oxygen supply to the fruit core is very limited and cells are quickly ‘out of breath’ when oxygen levels fall below the safety threshold”, he asserts.


Story Source:

The above post is reprinted from materials provided by European Synchrotron Radiation Facility. Note: Materials may be edited for content and length.


Journal Reference:

  1. Verboven, P. et al. 3-D gas exchange pathways in pome fruit characterized by synchrotron X-ray computed tomography. Plant Physiol., 147: 147: 518-527, (2008)

Cite This Page:

European Synchrotron Radiation Facility. "Apples And Pears Contain Pathways To 'Breathe'." ScienceDaily. ScienceDaily, 14 July 2008. <www.sciencedaily.com/releases/2008/07/080710110759.htm>.
European Synchrotron Radiation Facility. (2008, July 14). Apples And Pears Contain Pathways To 'Breathe'. ScienceDaily. Retrieved July 7, 2015 from www.sciencedaily.com/releases/2008/07/080710110759.htm
European Synchrotron Radiation Facility. "Apples And Pears Contain Pathways To 'Breathe'." ScienceDaily. www.sciencedaily.com/releases/2008/07/080710110759.htm (accessed July 7, 2015).

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