Proteins could help the apple industry extend the shelf life of premium apples

Two superstar apple varieties, Honeycrisp and Ambrosia, are a hit with consumers because of their superior quality in taste, firmness and appearance. Apple growers and packers charge a premium price for these varieties and use advanced storage technologies to ensure these high-demand varieties are available to consumers virtually year-round.

In prime condition, these apples are near perfect but keeping them that way requires a delicate balance of storage techniques. Storing them at a low temperature too early after harvest can cause a physiological disorder called soft scald.  It causes the delicate skin and underlying flesh on these apples to develop brown or black lesions which makes them unmarketable.

The Honeycrisp and Ambrosia varieties are known among growers and packers for having a sensitivity to this disorder and scientists are intent on identifying the biological triggers that cause it.  A study on the post-harvest storage of Ambrosia apples at three commercial orchards in British Columbia led researchers at Agriculture and Agri-Food Canada and Dalhousie University to discover a group of proteins they believe hold the key to helping the industry maintain the quality of these apples while in storage.

"We know there’s a relationship between this particular group of proteins and the development of soft scald disorder under cold stress in storage.  Now we’re validating our findings to determine if these proteins can be used as biological markers for detection, prevention and monitoring."

- Dr. Jun Song, Research Scientist, Agriculture and Agri-Food Canada – Kentville Research and Development Centre

The goal of this research is to help the apple industry in Canada improve storage techniques to reduce losses and expand market potential.

"We don’t know which orchard blocks of ‘Ambrosia’ apples are susceptible to soft scald in some years and which others are not, however, after they are placed into storage the symptoms develop and that can lead to significant losses. It would be extremely useful to be able determine the level of susceptibility so that susceptible fruit could be treated before storage to mitigate soft scald in those lots."

- Dr. Peter Toivonen, Research Scientist, Agriculture and Agri-Food Canada – Summerland Research and Development Centre

The next step is to validate the group of proteins as markers for the disorder. From there, detection tools can be developed to help growers and packers become more effective at reducing or eliminating the presence of soft scald disorder while in storage.

Key Facts

• Honeycrisp and Ambrosia are two of the fastest growing apple varieties in Canada.
• These high-quality varieties are susceptible to a storage disorder called soft scald which can lead to significant production losses.
• Researchers at Agriculture and Agri-Food Canada and Dalhousie University have found a group of proteins they believe could serve as biological markers for early detection and prevention of soft scald disorder.

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Related information

• Sweet Science: A new device for checking apple ripeness
• Kentville Research and Development Centre
• Summerland Research and Development Centre