Yam is the common name for some plant species in the genus Dioscorea (family Dioscoreaceae) that form edible tubers. Yams are perennial herbaceous vines cultivated for the consumption of their starchy tubers in many temperate and tropical regions, especially in Africa, South America and the Caribbean, Asia, and Oceania. The tubers themselves, also called "yams", come in a variety of forms owing to numerous cultivars and related species.

Although yams and sweet potatoes are both angiosperms (flowering plants), they are not related botanically. Yams are a monocot (a plant having one embryonic seed leaf) and from the Dioscoreaceae or Yam family. Sweet Potatoes, often called ‘yams’, are a dicot (a plant having two embryonic seed leaves) and are from the Convolvulacea or morning glory family.

Yams

Yams are closely related to lilies and grasses. Native to Africa and Asia, yams vary in size from that of a small potato to a record 130 pounds (as of 1999). There are over 600 varieties of yams and 95% of these crops are grown in Africa. Compared to sweet potatoes, yams are starchier and drier.

Sweet Potatoes

The many varieties of sweet potatoes (Ipomoea batatas) are members of the morning glory family, Convolvulacea. The skin color can range from white to yellow, red, purple or brown. The flesh also ranges in color from white to yellow, orange, or orange-red. Sweet potato varieties are classified as either ‘firm’ or ‘soft’. When cooked, those in the ‘firm’ category remain firm, while ‘soft’ varieties become soft and moist. It is the ‘soft’ varieties that are often labeled as yams in the United States.

Why the confusion?

In the United States, firm varieties of sweet potatoes were produced before soft varieties. When soft varieties were first grown commercially, there was a need to differentiate between the two. African slaves had already been calling the ‘soft’ sweet potatoes ‘yams’ because they resembled the yams in Africa. Thus, ‘soft’ sweet potatoes were referred to as ‘yams’ to distinguish them from the ‘firm’ varieties.

Today the U.S. Department of Agriculture requires labels with the term ‘yam’ to be accompanied by the term ‘sweet potato.’ Unless you specifically search for yams, which are usually found in an international market, you are probably eating sweet potatoes!

As you enjoy fresh produce, follow these safe handling tips to help protect yourself and your family.

Fruits and vegetables are an important part of a healthy diet. Your local markets carry a wide variety of nutritious fresh fruits and vegetables. However, harmful bacteria that may be in the soil or water where produce grows can come in contact with fruits and vegetables and contaminate them. Fresh produce may also become contaminated after it is harvested, such as during storage or preparation.

Eating contaminated produce can lead to foodborne illness, often called “food poisoning.” So as you enjoy fresh produce, follow these safe handling tips to help protect you and your family.

Buy Right

You can help keep produce safe by making wise buying decisions.

• Choose produce that is not bruised or damaged.
• When buying pre-cut, bagged or packaged produce — such as half of a watermelon or bagged salad greens — choose only those items that are refrigerated or surrounded by ice.
• Bag fresh fruits and vegetables separately from raw meat, poultry, and seafood when packing them to take home from the market

Store Properly

Proper storage of fresh produce can affect both quality and safety.

• Store perishable fresh fruits and vegetables (like strawberries, lettuce, herbs, and mushrooms) in a clean refrigerator at a temperature of 40° F or below. Use a refrigerator thermometer to check! If you’re not sure whether an item should be refrigerated to keep its quality, ask your grocer.
• Refrigerate all produce that is purchased pre-cut or packaged .

Separate for Safety

Keep fruits and vegetables that will be eaten raw separate from raw meat, poultry, and seafood — and from kitchen utensils used for those products.

• Wash cutting boards, dishes, utensils, and countertops with soap and hot water between preparing raw meat, poultry, and seafood and preparing produce that will not be cooked.
• If possible, use one cutting board for fresh produce and a separate one for raw meat, poultry, and seafood.
• If you use plastic or other non-porous cutting boards, run them through the dishwasher after use

Prepare Safely

When preparing any fresh produce, begin with clean hands. Wash your hands for at least 20 seconds with soap and warm water before and after preparation.

• Cut away any damaged or bruised areas on fresh fruits and vegetables before preparing and/or eating. Throw away any produce that looks rotten.
• Wash all produce thoroughly under running water before preparing and/or eating, including produce grown at home or bought from a grocery store or farmers’ market. Washing fruits and vegetables with soap, detergent, or commercial produce wash is not recommended. Produce is porous. Soap and household detergents can be absorbed by fruits and vegetables, despite thorough rinsing, and can make you sick. Also, the safety of the residues of commercial produce washes is not known and their effectiveness has not been tested.
• Even if you do not plan to eat the skin, it is still important to wash produce first so dirt and bacteria are not transferred from the surface when peeling or cutting produce.
• Scrub firm produce, such as melons and cucumbers, with a clean produce brush.
• After washing, dry produce with a clean cloth towel or paper towel to further reduce bacteria that may be present on the surface

What About Pre-Washed Produce?

Many pre-cut, bagged, or packaged produce items are pre-washed and ready-to-eat. If so, it will be stated on the packaging, and you can use the produce without further washing.

If you choose to wash produce marked as “pre-washed” or “ready-to-eat,” be sure that it does not come in contact with unclean surfaces or utensils. This will help to avoid cross contamination.

About Foodborne Illness

Know the Symptoms

Consuming dangerous foodborne bacteria will usually cause illness within 1 to 3 days of eating the contaminated food. However, sickness can also occur within 20 minutes or up to 6 weeks later. Although most people will recover from a foodborne illness within a short period of time, some can develop chronic, severe, or even life-threatening health problems.

Foodborne illness can sometimes be confused with other illnesses that have similar symptoms. The symptoms of foodborne illness can include:

• Vomiting, diarrhea, and abdominal pain
• Flu-like symptoms, such as fever, headache, and body ache

Take Action

If you think that you or a family member has a foodborne illness, contact your healthcare provider immediately.