Food Bug Zappers

In chapter 10 of Unnaturally Delicious, I wrote about a variety of food safety innovations.  Frank Yiannas, Walmart's vice president for food safety told me a bit about some of the technologies and efforts he's been involved with.  But, first on Walmart itself:

I started by asking about the size of Walmart. More than 120 million Americans (more than a third of the U.S. population) shop at Walmart every week. Does the sheer scale of the operation make the U.S. food system riskier? If Walmart has an outbreak, multitudes would be sickened. Yiannas replied: “One out of every four dollars spent on food are spent at a Walmart. We can make a big difference. Large organizations like Walmart result in a safer food system.” He points out that when Walmart makes a change, it affects the whole system.

He went on to tell me about how they're ensuring rotisserie chickens are properly cooked.  

To address this problem Walmart turned to the power of information technology and Big Data.28 Now all stores are equipped with new handheld sensors that are used to check cooking temperatures of every single batch. The sensors automatically record and send the information to the web in real time. During the month that health inspectors checked Walmart chickens ten times, the company recorded 1.4 million temperature checks. Whereas earlier inspection methods relied on taking a small sample of readings to check for compliance, Yiannas said the new approach is “N = all.” In other words, Walmart employees check every single chicken. Moreover, Walmart no longer has to wait on a report from an inspector or third-party auditor to learn the outcomes. Yiannas can check at any time during the day to see which stores are doing what they should to meet food safety standards. The troves of data can be exploited to find out which stores, which equipment, and which employees are doing better. Perhaps most important, it might just stop you and me from walking out the door with an undercooked chicken.

I also talked to Kevin Myers, the senior vice president of research and development for Hormel, who was involved in implementing a relatively new technology to help ensure safe meat: high pressure processing.  

High-pressure processing (sometimes also called pascalization after the seventeenth-century scientist Blaise Pascal, who studied pressure) allowed Hormel Foods to sanitize both the meat and the package it comes in. The process is particularly well suited for ready-to-eat foods because it takes place after the product is packaged and eliminates potential contamination which could occur after cooking and before packaging.

Myers said the process works by placing the packaged food in a chamber and submitting it to extreme levels of pressure. Have you ever jumped off the diving board at the deep end, only to have your ears hurt as you approached the bottom of the pool? That pain is caused by the pressure exerted on your eardrums by the water above you in the pool. At a depth of about ten feet, your ears are feeling about 4.3 pounds per square inch (psi) of pressure. If you could somehow swim to the deepest point in the ocean (about thirty-six thousand feet down), you’d feel more than 15,600 psi. Well, you wouldn’t actually feel anything because your body would be crushed well before you reached that depth. According to Myers, Hormel’s high-pressure processing system applies 87,000 psi to food products. That is five and a half times more pressure than would be felt at the deepest depth of the ocean.

All that pressure is enough to kill bacteria and other pathogens without adversely affecting the food itself.  Here's a photo of a high pressure pasteurization machine provided by Avure Technologies, which is finding applications of high pressure pasteurization for a wide variety of foods.

There is more in the chapter on Walmart, Hormel, and on innovators working on new, rapid food safety testing devices.