Tests Reveal What’s Hidden on Produce

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When Sugar Jones puts together a fruit salad for her kids' afternoon snack, the San Diego mother of two makes sure to give the apples a good scrub.

"Just making sure everything's clean inside the stem area and nothing gross hanging around," said Jones.

As a consumer columnist, she's always thinking about consumer safety.

She's also noticed fingerprints on apples in the store and has often thought about just how many people may have touched them.

NBCSanDiego also wondered just what would we find on the produce we all eat so we bought apples from several stores around San Diego county and took them to Quadrant Scientific to have the experts check them out in the lab.

Lab President Mark Shannon oversaw the experiment.

He put six apples to the test.

Half washed for 15 seconds with cold water (the minimum recommended by the USDA).

The other half, tested just as they came from the store.

"You just assume food from the grocery store is clean it's the logical thing to think about but it might not be," said Shannon.

Technicians used strict scientific procedures to test the fruit's surfaces.

"We will be able to tell you the approximate number of organisms we recovered from the surface just from the surface of one medium sized apple," said Tracey Minutolo.

NBCSanDiego returned the following week to find out the results.

Technicians found about a quarter million microorganisms on the surface of the unwashed apples, compared to just 5,000 on the washed apples.

It was the same story when they tested a vegetable.

"Same kind of thing, we found millions of cells on a carrot," said Shannon.

The good news? Not a trace of what Shannon says would be the biggest concern: fecal contamination. But they did find at least three different microorganisms: bacillus, leifsonia and micrococcus.

"Micrococcus is found on skin- so perhaps from the handling of apples," said Shannon.

In low numbers, not too alarming, Shannon said.

But if you had high concentrations, you might get sick he said.

"It's a numbers game, the body can only take too much of an insult so we don't want to be adding too much bacteria we want to keep it as little as possible," he said.

"With elderly folks, immuno-compromised people, young children, yeah those are some high numbers that we found," he said.

What surprised Shannon most was that vigorously washing the apples for 15 seconds in cold water reduced those microorganisms by 98%.

Even he is now a convert, promising to wash his apples more thoroughly.

Jones says she's also going to be a lot more careful in her kitchen:

"Now I'm probably going to put a timer on my kitchen sink and make sure I hit the 30 second mark," she said.

Maybe the most interesting advice from Mark Shannon is to wash produce even if you'll remove the peel.

For example: avocados.

He says, when you cut into produce, you're going push the microorganisms that are on the skin or peel into the meat. So when you eat the meat, you also eat those microorganisms dragged into it by the knife.

We also asked our lab expert about those soaps you can buy to wash produce.

He thinks they're a waste of money for home cooks, and says plain old water should do the trick.

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