When it comes to sources of foodborne illness, fruits and vegetables are hardly off the hook. Just about every kind—from cantaloupes, papayas, and strawberries to spinach, sprouts, and tomatoes—has been implicated in outbreaks in recent years.
Last summer, imported mangoes were deemed the likely source of a Salmonella-related outbreak that sickened more than 100 people across 16 states, many seriously. Just prior to that, domestic cantaloupes were implicated in another outbreak of Salmonella-related illness in 204 people across 22 states, two of whom died. And late in 2012, 147 people in 28 states became ill and 33 of them died from eating cantaloupes tainted with Listeria, in what has been the deadliest foodborne illness outbreak in the U.S. since the Centers for Disease Control and Prevention (CDC) began keeping track. Another 60 people fell ill in 2011 from E. coli linked to romaine lettuce. The list goes on and on.
How does produce get contaminated? While they grow, fruits and vegetables can pick up pathogens from soil, animal feces, and rainwater runoff. Inadequate cleaning of equipment and improper handling—at all points from the farm to your table—can also contaminate produce after harvest. According to the Food and Drug Administration (FDA), the 2011 Listeria-related outbreak may have been due to unsanitary conditions at the farm’s packing shed. In addition, the cantaloupes were not pre-cooled before they went into cold storage, which may have caused condensation on the rinds and subsequent growth of the dangerous bacteria.
In some cases, pathogens may take up residence in parts of produce that cannot be cleaned—and only cooking will effectively eliminate them. But washing your produce is usually enough to remove most surface microbes and thus minimize the risk; it also gets rid of soil and dirt and some pesticide residues.
Here are tips on what to wash and how. Some of this advice may sound like overkill, but it’s especially important if you are preparing food for young children, frail older people, or anyone with compromised immunity.
Five general produce safety rules
- Start with a clean kitchen, including cutting surfaces, colander, knives and sink.
- Wash your hands well before handling produce.
- Rinse produce under cold running tap water. In some cases, you’ll want to use a brush for extra cleaning.
- Blot dry with a paper towel or clean cloth to further reduce any pathogens that may be present.
- Wash fruits and vegetables right before you plan to eat them. Washing and then storing them can promote mold and bacterial growth.
Nine more produce safety tips
- Scrub firmer produce like potatoes, carrots, and cucumbers with a vegetable brush under running water to get at pathogens that may be in grooves or sticking to any waxy coating. For softer produce, like tomatoes, peppers, and peaches, rub them gently with your hands under running water. It’s often recommended that mushrooms be simply wiped with a wet paper towel or soft mushroom brush—but if needed, rinsing or spraying them with water, briefly and gently, is okay, too.
- With melons, wash the rind well before cutting to prevent any bacteria on the surface from being transferred to the inside by the knife blade.
- Yes, do wash your bananas—at least if you are going to handle the flesh. They could have bacteria on the peel. The same goes for oranges, lemons, avocados, mangoes and other fruits with skins or rinds that you peel with your hands or cut with a knife.
- Discard the outer leaves of lettuce. Rinse even the tightly packed leaves in the interior, individually when possible. You can use a salad spinner to dry them. One way to clean loose gritty greens, like spinach, is to immerse them in a large pot of cool water and allow a minute or two for debris to sink to the bottom; then lift out the leaves, rinse them in a colander, and spin dry.
- To clean berries, first pull off any leafy stems where bacteria may be lurking. Place in a colander and rinse or spray with water, shaking them gently. Blot dry gently. Some salad spinners come with special inserts to dry berries (and herbs).
- To wash herbs, dip and swish them in a bowl of water.
- Don’t use soap and detergents. They can leave residues that affect the taste and may not be safe to ingest. Special produce washes are expensive and not proven to be more effective than washing with water.
- Be aware of bruises. Bruised areas on produce may harbor bacteria. If there’s a small bruise, cut away a large section around it before washing. If there is significant bruising, especially on small fruits and vegetables like berries and grapes, toss them altogether.
- Wash organic fruits and vegetables as you wash conventionally grown produce. The same is true of locally grown produce and even produce from your own garden.