PERTH, AUSTRALIA — Plums: they're sweet, juicy, and packed with beneficial antioxidants and dietary fiber. Although there are many varieties available to consumers, there are two main types of the small, purple fruit: Japanese plums and European plums. Japanese plums are the most widely grown type and are round, while oval European plums are commonly used for making dried plums, or prunes.
Getting fresh plums to the marketplace has been a challenge for fruit producers. The short shelf life of Japanese and European plums limits export and shipping options—Japanese plums can typically be stored for only three to five weeks after harvesting. For years, researchers have tested a variety of techniques to extend the storage life of Japanese and European plums, including preharvest calcium application, postharvest heat treatment, application of an edible coating, cold storage, and "modified atmosphere storage". Results of the tests have been inconclusive and sporadic.
Ahmad Sattar Khan, a PhD student, and Dr. Zora Singh, Associate Professor of Horticulture at the Muresk Institute, University of Technology in Perth, Western Australia, recently carried out a research project attempting to extend the postharvest storage life of Japanese plums (Prunus salicina Lindl. cv. Tegan Blue). The study, published in the Journal of the American Society of Horticultural Science, tested the effects of modified atmosphere packaging (MAP), and the application of 1-methylcyclopropene (1-MCP), a fumigant, on Japanese plums, including the effects on the fruit's dietary antioxidants and overall quality.
According to the report, a combination of modified atmosphere packaging and 1-MCP had been shown to extend the storage life of plums with varying results, depending on storage conditions and type of polyethylene film used under MA storage.
The long-term storage study garnered important new information that will allow fruit producers and exporters to extend the storage life of Japanese plums for up to seven weeks. The researchers concluded that "1-MCP application in combination with MAP can be used effectively to reduce the ethylene biosynthesis and fruit softening during cold storage and to extend the storage life up to seven weeks followed by eight days of ripening without any adverse effects on the quality of the fruit."
Source: American Society for Horticultural Science
Wickson, a Japanese plum released by Luther Burbank and named after E.J. Wickson, friend and dean of agriculture at the University of California, Berkeley.
(Photo Credit: Photo by Peggy Greb)