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How Does Peanut Butter Get Contaminated With Salmonella, Anyway?

    According to an updated news release issued Thursday by the Centers for Disease Control and Prevention, sixteen people in 12 states have been sick with Salmonella, a bacteria that can cause gastrointestinal illness, after consuming Jif peanut butter products.

    The multi-state outbreak is still being investigated by the CDC, the US Food and Drug Administration, and other public health officials in the impacted states. The J.M. Smucker Company facility in Lexington, Kentucky produced all of the implicated peanut butter products, which totaled over 50 different varieties.

    The items have been voluntarily recalled and are no longer on shop shelves, but anyone who has Jif peanut butter at home is asked to check the lot codes on those products and discard or return them to the retailer if they are affected.

    The current Salmonella investigation adds to a growing number of prior outbreaks in peanut butter products, the most noteworthy of which occurred in 2008–2009, when contaminated King Nut brand creamy peanut butter affected 714 individuals and nine people died. In 2012, 42 Salmonella infections were linked to Trader Joe’s peanut butter (manufactured by Sunland, Inc.), and in 2015, 13 Salmonella infections were linked to JEM Raw brand sprouting nut butters.

    All of this begs the question: how does peanut butter become contaminated with Salmonella, a disease more commonly associated with raw chicken or eggs, and what makes it so susceptible? Here’s what you need to know.

    Manufacturing Issues May Lead to Salmonella in Peanut Butter

    To grasp the connection between peanut butter and Salmonella, it’s necessary to first understand how peanut butter is created. Peanut butter is made from raw, shelled peanuts that have been roasted and cooled, according to Vijaya Surampudi, MD, clinical nutrition specialist at UCLA Health. She went on to say that the peanuts are then processed and heated again throughout the grinding process.

    According to Darin Detwiler, LPD, a professor of food policy and corporate social responsibility at Northeastern University and author of Food Safety: Past, Present, and Predictions, heating the peanuts and keeping them dry is a crucial step in keeping your peanut butter secure from contamination.

    “Peanut butter is created from shelled and crushed peanuts that are normally stored in unprotected mounds until ready for the next stage of food processing or delivery to another enterprise,” Detwiler explained. “The majority of Salmonella instances in peanuts are caused by rainwater bringing faeces onto the product, or animals—birds or, more commonly, rodents—coming into close contact with the product.”

    “If the item is heated to a high enough temperature, held at that temperature for enough time, and cooked completely,” Detwiler added, roasting the tainted peanuts can help kill the Salmonella. However, after boiling and grinding, the peanut butter must maintain its sterilised quality. “If correct sanitation measures are not followed, roasted peanut butter can become contaminated in the production plant.”

    Roasting tainted peanuts, on the other hand, might sometimes result in the growth of a heat-tolerant bacteria. “That’s why, in addition to ensuring that the facility is well kept, cleaning and sanitising the equipment and the facility is so vital,” Ellen Shumaker, PhD, food safety extension associate at North Carolina State University, told Health.

    Peanut Butter Is an Ideal Place for Salmonella to Survive

    Salmonella may not be able to thrive in peanut butter, but it can live for “several months” if it gets into the product, according to Detwiler.

    “Peanut butter is a low-moisture food,” Abby Snyder, PhD, assistant professor of food science at Cornell College of Agriculture and Life Sciences, told Health. “There isn’t enough accessible water to enable the formation of microbial diseases like Salmonella.” “However, while Salmonella cannot grow, it can persist in low-moisture foods like peanut butter for long periods of time.”

    According to Shumaker, the high fat content of peanut butter may even act as a layer of protection for the bacteria. She cited a research published in the Journal of Applied Microbiology in 2000 that revealed the bacteria could survive in peanut butter jars for up to 24 weeks.

    Another significant issue is that peanut butter is classified as a “ready to eat” item, which means that it is frequently consumed without being cooked, increasing the risk of catching Salmonella if the jar is contaminated, according to Snyder.

    What to Do if You Have Recalled Peanut Butter at Home—And What’s Being Done About Future Outbreaks?

    People should not eat the recalled Jif peanut butter products, according to the FDA and the CDC; they should be thrown away or returned to the store. This also applies to pets and other animals, who should not be fed possibly contaminated foods.

    The organisations also recommend that you wash any surfaces or containers that have come into contact with the contaminated foods with hot, soapy water.

    If you’ve eaten any of the recalled products and become ill, which can happen anywhere from 12 to 72 hours after a Salmonella infection, you should see your doctor. The most typical signs of a salmonellosis infection include diarrhoea, sometimes bloody diarrhoea; a temperature of more than 102 degrees Fahrenheit; severe vomiting; and dehydration.

    According to Shumaker, the recent epidemic demonstrates that the entire food business “has to be on high alert for Salmonella at all times.” Despite the FDA’s recent updates and creation of more stringent food safety requirements, particularly with the Food Safety Modernization Act of 2011, businesses must continue to invest in and prioritise food safety and sanitation programmes.

    “There must be structural aspects to keep rodents and precipitation out of the products,” Detwiler said. “To avoid such events from injuring or killing customers, as well as to meet regulatory and legal responsibilities, frequent and effective testing as well as necessary measures are required.”

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