Growers considering how to keep their produce properly cooled may have three options available rather than just two. Most conventional cooling is done via an iceless or ice process, but a Canadian company has created ice slurry which doesn’t face contamination and is able to keep product at a very consistent temperature.
Decreased risk of contamination
Ice slurry, marketed as DeepChill by Sunwell Technologies, is produced in generators by freezing water in a cylindrical chamber with augers that continuously sweep the walls to prevent the formation of sharp-edged flake ice. The result is round pearl-like crystals formed in suspension.
Emily Wright with Sunwell says using the ice slurry over other forms of ice (such as flake) results in more even and rapid cooling. “You also decrease the risk of contamination since DeepChill systems are completely closed, unlike flake ice drums and ice crushers that are open to bacteria and contaminants in the environment.” She also notes that’s a safer process since it’s closed to contaminants, unlike flake ice systems and crushers.
Rapid cooling and longer shelf-life possible
Wright says there are also benefits over going iceless, while some would say it saves on adding extra weight and extra cost during transport. “That can risk quality, shelf-life and spoilage - and your bottom. If your produce isn’t properly preserved, you just won’t have the same level of quality or duration of shelf-life that you could have had by storing it in slurry.” She says removing field heat through rapid cooling is key to locking in the highest quality possible. “After that, it’s a matter of maintaining that ideal low temperature until the product is at its final destination.”
Testing done for certain produce so far
Not all produce may need to be kept at the low temperatures that the slurry maintains product at. Wright says so far they’ve only done tests or installed systems for use with the listed produce on their website, which includes broccoli, asparagus, corn, Brussels sprouts, cilantro and green onions. “It’s not to say that it can’t be used to ice other produce that needs to be kept at near 0°C, it all depends on the application, so we’re open to people contacting us and asking about other types of produce,” she noted.
After the crystals are formed in the generators, they’re pumped into a storage silo where they’re kept until the user is ready to cool their product. “After the DeepChill is harvested from the silo, it’s mixed with water and brought to the client’s ideal consistency, and pumped over produce, cooling it in a matter of minutes.” She says the ice slurry can be used at every step, from cooling immediately after harvest, to storage, to shipping.
Longer produce storing possible
Wright says clients have been able to store produce in the ice slurry for several weeks while maintaining peak freshness, which can mean selling when prices are preferable. “Clients have used it to also open up new geographical markets. Whether the constraints were product quality or distance, we’ve helped clients improve quality to meet the high standards of desirable markets such as Canada and the US.” Even, she says, securing deals in Japan now that they can maintain quality over long distances.
