THE OHIO STATE UNIVERSITY OHIO STATE UNIVERSITY EXTENSION OHIO AGRICULTURAL RESEARCH AND DEVELOPMENT CENTER

April 12, 2013 Dry kidney beans By Martha Filipic 614-292-9833 need to be boiled [email protected] Editor: A few weeks ago, I contacting their doctor. Other types of beans also This column was reviewed by Linnette Goard, field specialist soaked some dry kidney contain PHA, but it’s much more in food safety, selection and beans to prepare them concentrated in red kidney beans. For management for Ohio State for some chili. My sister example, the unit of measurement University Extension, the told me that before for the toxin is called “hau,” for outreach arm of the College “hemagglutinating unit.” Raw red of Food, Agricultural, and adding them to the kidney beans have anywhere from Environmental Sciences. chili, I should boil them 20,000 to 70,000 hau, but that drops to 200 to 400 hau when the beans to make sure the beans Communications and are fully cooked — not enough to be wouldn’t make us sick. I Technology a problem. White kidney beans, or Strategic Communications did, but was that really cannellini beans, contain only about 2021 Coffey Road necessary? one-third of the toxin as red kidney Columbus, OH 43210-1044 614-292-2011 You’ve got a knowledgeable sister. beans. Broad beans, or fava beans, Many people don’t know the risk contain just 5 to 10 percent of what’s 208 Research Services posed by dry red kidney beans when in red kidney beans. Building they’re not cooked properly. The FDA recommends these steps 1680 Madison Ave. The problem isn’t bacteria, but for preparing dry red kidney beans: Wooster, OH 44691-4096 330-263-3780 “phytohaemagglutinin,” also called • Soak the beans for at least five PHA, or kidney bean lectin. Lectin hours in water. It’s not a bad idea to Ohio State University Extension is a type of protein that performs all change the water periodically, but it’s embraces human diversity and not necessary for safety. is committed to ensuring that all sorts of functions in both plants and research and related educational animals. But some types of lectin, • Drain the beans from the final programs are available to clientele including this one, can be toxic at soaking water. on a nondiscriminatory basis without regard to age, ancestry, high levels. • Boil the beans in a pot of color, disability, gender identity or If this lectin isn’t destroyed by fresh water for at least 30 minutes. expression, genetic information, thorough cooking, you’ll be sorry. Note: Research indicates that the HIV/AIDS status, military status, national origin, race, religion, sex, According to the U.S. Food and toxin is destroyed when boiled at sexual orientation, or veteran Drug Administration’s “Bad Bug 212 degrees F for 10 minutes, but status. This statement is in scientists recommend 30 minutes to accordance with United States Book,” eating as few as four or five Civil Rights Laws and the USDA. improperly cooked red kidney beans be certain the beans reach the proper Keith L. Smith, Associate Vice can cause severe vomiting within a temperature for the amount of time President for Agricultural Administration; Associate Dean, few hours, followed by diarrhea. necessary. Don’t use a slow cooker: It College of Food, Agricultural, and Although some cases have likely won’t get hot enough. Environmental Sciences; Director, required hospitalization, people Chow Line is a service of Ohio Ohio State University Extension; and Gist Chair in Extension normally feel better within three State University Extension, the Ohio Education and Leadership. to four hours after symptoms start. Agricultural Research and Development For Deaf and Hard of Hearing, Center, and the College of Food, please contact Ohio State That’s one reason why authorities University Extension using your suspect there aren’t many recorded Agricultural, and Environmental preferred communication (e-mail, cases of this particular foodborne Sciences. Send questions to Chow relay services, or video relay services). Phone 1-800-750-0750 illness in the U.S.: People usually Line, c/o Martha Filipic, 2021 Coffey between 8 a.m. and 5 p.m. EST begin to get over the illness just Road, Columbus, OH, 43210-1044, or Monday through Friday. Inform the about the time they might think of [email protected]. operator to dial 614-292-6181.