The whole cantaloupes now available in the stores are safe to eat — as long as basic food-safety practices are followed — and they have no connection with the Listeria-contaminated cantaloupes that as of Sept. 24 have sickened at least 61 and killed 10 or more people, several food-safety experts told Food Safety News.


The reason for those assurances comes down to this: The cantaloupe growing season in the area of Colorado where the farm linked to the Listeria outbreak is located is over.

Steve Patricio, chairman of the California Cantaloupe Advisory Board, told Food Safety News on Sept. 23 that no Colorado cantaloupes have been shipped out of that growing region for more than two weeks now.

“They’re no longer in the market,” he said, referring to the contaminated cantaloupes. “This is behind us.”

The president and CEO of Westside Produce, a Central Valley California shipper and packer of cantaloupes and honeydew melons, Patricio is also the chairman of the Center for Produce Safety’s Advisory Board.

“Most definitely, cantaloupes are safe,” he said. “Consumers can buy melons without a second thought of risk. The cause of the outbreak has been tracked and traced. Those melons are no longer available.”

Public health officials have concluded that the source of the Listeria outbreak was cantaloupe grown at Colorado-based Jensen Farms Inc. and sold under the brand name Rocky Ford or Frontera Produce, Rocky Ford Cantaloupes. The company voluntarily recalled its cantaloupes shipped between July 29 and Sept. 10.  Patricio said 300,000 cartons were recalled. Cartons generally hold from 12 to 18 cantaloupes.

Although the cantaloupes were shipped to 22 states, Patricio said the recall represents an isolated incident involving just one farm/shipper/packer.

Putting the recalled 300,000 cartons into perspective, Patricio said that in August alone, California shipped 10 million cartons and that in the state’s 5-month season, it generally ships 30 million cartons overall.

Even so, he knows that “the tragedy will grow,” and illnesses connected to the contaminated cantaloupe will continue to be verified.

That’s because the incubation period for the strain of Listeria that caused the multistate outbreak is about 3 weeks, although it can take as long as 2 months for it to develop after a person has been exposed to contaminated food.

According to the Centers for Disease Control and Prevention, a person infected with the bacteria usually has a fever and muscle aches, which are often preceded by diarrhea or other gastrointestinal symptoms. Additional symptoms can be a headache, stiff neck, confusion, loss of balance and convulsions.

Anyone who has eaten cantaloupe and is experiencing those symptoms is advised to contact a doctor.

In the United States, an estimated 1,600 people become seriously ill with Listeria each year. Of these, 260 die.

Listeria is usually linked to deli meats, hot dogs, and dairy products. Until this recent outbreak, whole cantaloupe had never been linked to  Listeria outbreak, although cases of E. coli and salmonella have been linked to cut cantaloupe.

Patricio praises the Food and Drug Administration, the CDC, public health officials and the food-safety community for their “maturity” in handling the situation. He said that Colorado started warning consumers early on and that there has been a lot of openness about the exact source of the outbreak.

“Because of that, they’ve saved lives and prevented a lot of illnesses,” Patricio said, contrasting that with previous outbreaks in which public-health officials and agencies were guarded about the information they had.

Trevor Suslow, Extension research specialist in food safety at UC Davis, agrees with Patricio that cantaloupes are safe to eat as long as some basic food-safety safeguards are taken — as is true with any fresh produce.

“These kind of events always cause one to pause,” he told Food Safety News. “But it’s important to remember that people in this country eat a lot of cantaloupes.”

He said the outbreak certainly won’t change his eating habits.

“It was an isolated, small event,” he said, referring to the amount of cantaloupes produced by the farm linked to the outbreak. “There’s no reason to believe there’s any difference in the safety of cantaloupes on the market now than before the outbreak.”

Cantaloupe food safety

Whole melons

Because cantaloupes are grown in close contact with the ground, they can occasionally become contaminated with bacteria from the soil, water, or animals, according to a University of California publication about safe handling of cantaloupes. In addition, they can be contaminated by human contact during or after harvest.

Suslow, one of the authors of the publication, said that consumers should spend some time looking at the cantaloupes in the stores or other places where they’re sold and select those free of blemishes, cuts, sunken areas, or mold growth. (However, cantaloupes usually have an area that’s a lighter color than the rest of the melon because that’s where the melon has been resting on the ground while it’s been growing.)

“Choose the sound, intact ones,” Suslow said.

Once you’ve brought the melon home, don’t wash it until you’re ready to eat it, he said. If it’s not quite ripe, it’s fine to keep it on the kitchen counter for a day or two, but, again, don’t wash it then or before you put it into the refrigerator. The reason for that, he said, is that cantaloupes are a “desert fruit” and need to be dry. Wetting them and putting them into the refrigerator can trigger mold.

It’s also important to remember to wash your hands before and after handling cantaloupe and to always use clean equipment, utensils, and cutting surfaces. Also, if you’ve kept the cantaloupe on the counter before putting it in the refrigerator, clean the counter once you transfer the melon to the refrigerator.

When you put the melon into the refrigerator, don’t let it come into contact with other foods. That will ensure that foods such as meat and poultry won’t contaminate it — or if there’s bacteria on the surface of the melon, that the bacteria won’t contaminate any of the food in your refrigerator.

The best temperature to store a ripe cantaloupe is 36 to 41 degrees F (2.2 to 5 degrees C). To prevent the melon from drying out, the best humidity level is 95 to 100 percent. For that reason, the best place to put a cantaloupe is in the refrigerator’s crisper.

When purchased from a grocery store, a cantaloupe will keep in the refrigerator for about 5 days, depending on how ripe it was when it was put there. Cantaloupes fresh from the field or garden will last from 5 to 15 days, depending on the variety and growing conditions. The riper the melon, the shorter the keeping time.

Once you’re ready to eat the melon, wash it under running water with a clean vegetable brush. That’s important, said Suslow, because the spaces within the netted rind on the melon protect the bacteria and make it harder to remove any that might be there.

After washing the melon, blot it with paper towels to remove excess water. Then put the melon on a clean surface — one that hasn’t come into contact with meat or poultry or other foods that could cause cross-contamination — and cut off the stem end about 3/4 to 1 inch from the end, using a clean kitchen knife to do this. (It’s recommended that you don’t do this in the kitchen sink.)

Place the melon on a clean cutting board, plate or other clean surface with the cut end facing down.

Using a clean knife, cut the melon from the blossom end to the stem end. Follow this by washing the knife with clean running water and setting it aside.

Gently scrape out the seeds with a clean spoon and cut the melon into slices or whatever is desired.

Don’t use dish soap or detergent, neither of which is recommended or approved for washing fruits and vegetables. Because cantaloupes are so porous, they can absorb detergent residues.

Suslow said that even if you wash the rind, you should avoid arranging the slices in a way that allows the rind to touch the melon’s edible flesh, especially if you’re serving people susceptible to food poisoning such as young children, older people, pregnant women, and those with weak immune systems.

Melon that isn’t eaten should be peeled, covered and refrigerated. But toss any that’s been kept out at room temperature for longer than 2 hours, or 1 hour when the temperatures are over 90 degrees F.

All of these food-safety practices should also be followed when using melons grown in a garden.

Sources for information about microbial food safety pertaining to home gardening and edible landscapes can be found here.

“It all fits together,” said Suslow. “You do as much as possible to stop contamination from being introduced.”

Drying and canning cantaloupe is not recommended. In fact, because cantaloupes have low acid levels, canning them can support the growth of the bacterium that causes botulism, a potentially fatal type of food poisoning.

Cut cantaloupe

In some cases, already-cut cantaloupe from the store or served in a restaurant, for example, has been linked to foodborne illnesses such as E. coli O157:H7 and Salmonella. And on Sept. 23, a Kansas food processor recalled fresh cut cantaloupe chunks and fruit medley containing cantaloupe because they may be contaminated with Listeria monocytogenes bacteria that have caused the multistate outbreak.

According to the UC Davis publication, storing cut melons at room temperature or other warm conditions such as in a hot car or at a picnic can lead to rapid growth of harmful bacteria on the melon’s flesh.

If you buy cut or diced cantaloupe, make sure it’s properly chilled, preferably in the refrigerated display case. And if cut or diced melons are displayed on ice, they should be surrounded by ice. In addition, the surface container or wrap should be cold to the touch, according to the same UC Davis publication.

The optimal storage temperature for ripe cantaloupe is 36 to 41 degrees Fahrenheit.

In the kitchen

Information about how to “super safe” your kitchen from Listeria is available here.