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Eating fresh, local Ontario grapes is a treat that could only be enjoyed for a short time every year – until recently.
The Sovereign Coronation variety is the grape of choice for many growers since it can withstand the province’s cold weather, but the quality of the fruit deteriorates quickly after harvest.
The Background
The Result
In other countries, pads infused with sulphur dioxide (SO2) are placed in the storage container to maintain grape freshness.
After trying different concentrations of SO2 and evaluating the pads’ effectiveness after three, five and seven weeks of storage, researchers determined the best treatment: a dual release pad that sends out a high concentration of SO2 in the first 24 hours, and then a slower rate of release over many days. Using these pads, along with careful handling during the harvest, removal of decayed and damaged fruit, and quick cooling of fruit following harvest resulted in grapes that stayed fresh and marketable for five weeks. That’s more than twice as long as previously possible.
The Impact
A new storage protocol has more than doubled the storability of Sovereign Coronation grapes allowing freshness to be maintained for five weeks.
A Canadian company is now a licensed distributor of sulphur pads for Ontario’s grape growers.
103 tons of grapes are being diverted from the food waste stream.