Food processors are always looking for better ways to improve safety and prolong shelf life. You’ve probably heard of canning, preservatives, and irradiation. But all these technologies come with considerable flaws--spinach turns to tasteless gray mush or the label lists a scary-sounding bath of sodium benzoate.
Glenn Hewson says there’s another way: It’s called high-pressure processing. As the vice president of marketing for Avure Technologies, one of the largest manufacturers of pressure processing equipment, he believes an orphaned technology once used to manufacture synthetic diamonds (really!) represents one of the most promising food-safety innovations in years. The high-pressure business has already hit grocery stores--treating packaged guacamole and ground beef patties--and it may soon be arriving at a juice bar near you.
In March, Starbucks unveiled its first Evolution Fresh storefront in Seattle, highlighting a line of fresh, “never heated” smoothies and custom juice blends. “When Starbucks comes in and says, ‘Hey, we believe this is the future of beverages,’ everybody’s got to sit up and notice,” Barb Stuckey, a professional food developer at Mattson, told me. “So there’s a lot of activity and there’s a big player who’s now just basically anted up and said, ‘We’re in the game.’”
The juices get treated in a large, stainless-steel self-contained processing units. It squeezes 2,000 liters of juice every hour, subjecting the liquid to 87,000 pounds of pressure per square inch. For a sense of that pressure: A household pressure cooker operates at 15 psi. Swim three miles below the ocean and you’re at 7,000 psi. Take two full-grown, male African elephants and convince them to stand on the cross-section of a dime: 30,000 psi. Now, multiple that by a factor of three. As the pressure inside the processor increases to 87,000 psi, any microbes present in the juice experience an instantaneous decrease in the volume of the liquid surrounding them. Take a look at them under a microscope and you’ll see a bunch of dead microbes with collapsed cell walls.
Unlike pasteurization or pressure canning, high-pressure processing leaves a food’s texture, flavor, and nutrition largely intact. According to some preliminary research published in Innovative Food Science & Emerging Technologies (funded in part by Avomex--the parent company of Fresherized Food, a maker of high-pressure processed guacamole), the process appears to actually increase concentrations of some nutrients. Moreover, the flavors tend to meld and marry, much like cooking. As Stuckey told me, “You get all the benefits of cooking without the downsides.”
For more videos and stories on innovative solutions in food technology, check out the rest of our Feeding the Future series.