ATLANTA -- Retailers looking for a magic bullet to increase the shelf life of value-added products are going to be disappointed.
Prolonging shelf life consists of doing a lot of little things correctly, according to panelists speaking at the Arlington, Va.-based International Fresh-cut Produce Association convention here.
"I'm not sure we're going to be able to provide any magic potions or formulas for you that will allow you to quadruple your shelf life overnight," said Devon Zagory, a fresh-cut consultant with Devon Zagory & Associates, Davis, Calif. "But I think if we pay attention to the many important little things, they will add up to improved shelf life."
James Gorny, a post-doctoral researcher with the University of California at Davis department of pomology, said there are three foundations to improved shelf life.
"Keep it cold, keep it clean and move it fast," he said. "Temperature control, sanitation and fast movement are really the modus operandi of this industry."
Packaging will only go so far in improving shelf life, Gorny added. "You don't know how many processors and other people tell me if they could get the right bag, they could get a 14-day shelf life. I really don't think that's the case," he said. Modified atmosphere packages will help improve shelf life somewhat, he said, but packaging can't overcome temperature abuse.
Zagory said processing and handling methods also play an important role in shelf life. For example, using dull instead of sharp knives, and chopping products instead of slicing them, can shorten shelf life.
Chopping products with dull knives allows more bacteria to grow, he explained; slicing fruits and vegetables with sharp knives is much better for shelf life.
What's more, bacteria may be more often a sign of deteriorating shelf life, not a cause, he said. "I think bacteria can cause the end of shelf life in some cases. But I suspect that, more often, bacteria are signaling the end of shelf life," he said. "And by signaling the end of shelf life, they're telling us that somewhere, something has gone wrong. What went wrong has allowed the bacteria to begin to propagate, to begin to reproduce."
By examining what causes the end of shelf life, it's possible to root out the problem. "Let's isolate that problem and try to understand the genesis of that problem. I think that problem can give us a lot of information about what we did wrong," he said. Adapting the product to the packaging and processing methods is another way to improve shelf life, according to Trevor Suslow, extension specialist for the University of California at Davis department of vegetable crops.
Some traits, or combinations of traits, might work better with some types of processing and packaging than others, he said.
The traits desirable for whole melons may be different from those desired for processing, said Suslow, quoting a study done by Michigan State University.