It just takes one hot berry in the middle of one clamshell to start a chain reaction of respiration and ethylene production that can rot an entire crate of fruit and speed deterioration in adjacent crates.
The best way to stop that wave of decomposition is to cool it, according to Jean-Pierre Emond, the principal scientific advisor for the international Cool Chain Association, Luxembourg, and leader of a project at the University of South Florida Polytechnic, Lakeland, Fla.
Emond is the dean of the university’s College of Technology and Innovation and his research group developed a new reusable crate for strawberries that he said enhances uniform air flow and reduces cooling time by as much as 40%.
“We made the prototype and conducted a full-scale cooling test with strawberry growers in this area,” Emond said June 7. “We are ready to go into production.”
Canadian IPL Inc., a packaging manufacturer, provided $335,000 toward Emond’s research and may soon start production of the new strawberry crates. Emond said they can be made from virgin resins or recycled plastic.
Now the researchers plan to develop crates for the physical protection and temperature management needs of other produce. Emond said crates for many produce commodities have flaws similar to those he addressed in the strawberry project.
Traditional cardboard crates have vent holes to assist air flow during precooling, but they are designed to handle various configurations and numbers of clamshells. Consequently, the crate vents don’t line up with the clamshell vents and circulation is inhibited, he said.
Emond said restricted air flow causes post-harvest delays, higher costs because of longer cooling times and shorter shelf life. The cardboard crates can also weaken if they become wet and can then become a growth medium for molds.
“This is a project that will benefit the farmer, the distributor and the retailer, as well as the consumer,” Emond said.
“When consumers get a package of berries home and find a bad one in the middle they think the retailer hid it in there. They don’t understand that the retailer did not pack the clamshell.”
The new plastic crates are stronger than the traditional cardboard ones. The reusable plastic containers stack perfectly, Emond said, without damaging the fruit on the bottom. They provide added protection for fragile fruits, and can be reused at least 50 times.
Emond has been working on containers for temperature sensitive products for years, completing 50 research projects since 1993. His work has earned two “AgCellence Awards” from Agriculture and Agri-Food Canada, a division of the Canadian Agriculture Ministry. He also holds seven patents related to packaging and radio frequency identification applications.