Conservation techniques have been tested on new varieties of American-Japanese plums since the start of the millennium.
The studies carried out by Cefel will help determine the best dates for harvest and how to improve fruit conservation as well as improve the visual aspects and maintain quality (notably firmness). Many conservation techniques have been tested since the start of 2000 : under a controlled atmosphere, eliminating ethylene in the atmosphere and application of 1-MCP (SmartFreshSM) in cold rooms.
As for many fruits, a premature harvest allows to have a better firmness and reduces the risk of fruits falling from the trees when maturity is reached or being damaged by storms. But the fruits can be too acidic if kept for long periods in cold rooms. Ageing tests in 10-15°C over a few days after harvest gave interesting results in developing the colour of varieties such as Sun Kiss that need to be a deep yellow when they reach the stores. A drop in acidity was also noted as was a loss of firmness if the harvest was too early, but no increase in sugar was seen. On the contrary, ageing provoked a decrease in IR which goes against fruits harvested early whose sugar levels are often not yet very high.