Science Friday Folgen

New Cold Storage Method Solves Freezer Burn—And Saves Energy Have you ever pulled a long-anticipated pint of ice cream out of the freezer, only to find the strawberries crunchy and the normally creamy substance chalky and caked with ice? Freezer burn, a phenomenon caused by water in food crystallizing into ice inside the ice cream or fruit or meat during freezing, is a menace to taste buds, a driver of food waste, and even damages some of the nutritional benefits of food. And it’s always a risk as long as food preservation relies on very cold temperatures. Even flash-freezing, which works much faster, can still create small ice crystals. But United States Department of Agriculture (USDA) food scientists, working with a team at the University of California-Berkeley, have a method that could help solve this problem. Normal food freezing, called isobaric, keeps food at whatever pressure the surrounding air is. But what if you change that? Isochoric freezing, the new method, adds pressure to the food while lowering temperature, so the food becomes cold enough to preserve without its moisture turning into ice. No ice means no freezer burn. And, potentially, a much lower energy footprint for the commercial food industry: up to billions fewer kilowatt-hours, according to recent research. Ira talks to USDA food technologist Cristina Bilbao-Sainz and mechanical engineer Matthew Powell-Palm about how pressure and temperature can be manipulated to make food last longer, and hopefully taste better. Plus, the challenges of turning a good idea into a widespread technology. Koji: The Mold You Want In Your Kitchen When chef Jeremy Umansky grows a batch of Aspergillus oryzae, a cultured mold also known as koji, in a tray of rice, he says he’s “bewitched” by its fluffy white texture and tantalizing floral smells. When professional mechanical engineer and koji explorer Rich Shih thinks about the versatility of koji, from traditional Japanese sake to cured meats, he says, “It blows my mind.” Koji-inoculated starches are crucial in centuries-old Asian foods like soy sauce and miso—and, now, inspiring new and creative twists from modern culinary minds. And Shih and Umansky, the two food fanatics, have written a new book describing the near-magical workings of the fungus, which, like other molds, uses enzymes to break starches, fats, and proteins down into food for itself. It just so happens that, in the process, it’s making our food tastier.  You can grow koji on grains, vegetables, and other starchy foods, and make sauces, pastes, alcohols, and vinegars. Even cure meats. Umansky and Shih say the possibilities are endless—and they have the koji pastrami and umami popcorn to prove it.   The Bacteria Behind Your Favorite Blues, Bries, and More Cheese lovers, you can thank microbes for the flavorful funk of Camembert cheese and the perforated pattern of Swiss. According to microbiologist Rachel Dutton, one gram of cheese rind is home to 10 billion bacterial and fungal cells. Dutton describes our favorite cheese-microbe pairings and explains why the cheese rind is ripe for teaching us about the basic interactions of bacteria.   The World According To Sound: When Your Wine Bottle Sings A few years ago, Chris Hoff was making himself some plum wine. He had a nice big plum tree in the apartment he was renting in San Francisco, and it had been a plentiful year. During the process he came across a beautiful, simple sound that made him get out his recording gear. It came from his little metal funnel. Each time Hoff poured liquid through his funnel to fill a bottle, it made this pleasant rising arpeggio of bubbles. When the pitch reached its height, the bottle was filled, and Hoff moved on to the next one. He liked it so much that he grabbed his small handheld recorder and captured the sound. This simple, everyday sound is the result of a complex interaction of the liquid, bottle, air, and funnel. While water pours down through the funnel, air is being forced out of the bottle and up through the liquid, where it makes a bubble on the surface and then pops. As the level of liquid decreases in the funnel, the pitch of the popping bubbles rises. Read more at sciencefriday.com.     Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

A More Delicious COVID Screener One of the most bizarre symptoms of COVID-19—a nearly surefire way to know if you have been infected—is a loss of taste or smell. Estimates of how many people are impacted range wildly, with the highest estimates reaching 75 to 80% of COVID-19 survivors. There’s still a lot scientists don’t understand about why this happens and what part of the olfactory system or brain is actually responsible for this change. Researchers at Ohio State University are trying to figure out more about how COVID-19 impacts taste and smell using a familiar and tasty item: hard candy. Study participants eat an uncolored piece of candy each day and describe the flavor. If a participant is suddenly unable to identify which fruit the candy is emulating … well, it’s time to take a COVID test. Joining Ira to talk about this delicious research and learning more about how COVID-19 impacts our senses is Chris Simons, sensory scientist at Ohio State University in Columbus, Ohio.     Laugh And Learn With The Ig Nobel Prizes This year, even though many people may be still hesitant to gather together for the holidays, a Science Friday holiday tradition lives on—our annual post-Thanksgiving broadcast of highlights from the Ig Nobel Prize ceremony, now in its 31st first annual year.  Marc Abrahams, editor of the Annals of Improbable Research and master of ceremonies for the prizes, joins Ira to present some of the highlights from this year’s awards—from research into the microbiology trapped in the gum on the sidewalk to a transportation prize for scientists who discovered the best way to safely transport a rhinoceros long distances. (Dangle it upside down under a helicopter.) Tune in to hear about research involving the kinetics of crowds, the communications of cats, thoughts about the evolutionary history of human beards, and more.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Blunting The Force Of Disease Is Complicated  COVID-19 vaccines are highly effective at preventing severe disease. But their efficacy in lab-controlled trials may not exactly correlate to how well they work in the real world. David Kaslow, chief scientific officer at the global public health nonprofit PATH, explains that a factor known as the “force of infection” plays a role in determining how well vaccines work. The force of infection describes the attack rate of a pathogen—the amount of time it takes a susceptible individual to get infected in a given population.  In a study recently published in the academic journal NPJ Vaccines, Kaslow and his colleagues found that in vaccine trials for rotavirus and malaria in Africa, efficacy could vary widely between two trial sites. When there were many infections in the community, the overall efficacy of the vaccines appeared lower than in communities where disease incidence was low.  While the same sort of studies haven’t yet been done on the coronavirus outbreak, Kaslow argues that similar factors may be at play now—pointing to a continued need for non-pharmaceutical measures to control transmission, from masking to social distancing.       The Chemistry Of The Perfect Cookie With several major food-related holidays on the horizon, we’ve got a challenge for you—checking your cookie chemistry. Each batch of cookies you make has the potential to be a mini-science experiment, with the specific ingredients you use, the ratios between them, and cooking times and temperatures all variables in the mix.  Jennifer Powers, a science educator at the Oregon Museum of Science and Industry, discusses the role of types of sugar in transforming your cookie’s texture from chewy to crispy. She encourages listeners to take on her educational resource—the Cookie Chemistry Challenge—to engineer the best batch of cookies possible.       Food Failures: Add A Dash Of Science To Your Thanksgiving Recipes This Thanksgiving, put your cooking skills to the test. Looking for tips to avoid singed sweet potatoes, acrid apple pies, and a burned bird? In this archival segment from November 18, 2016, Molly Birnbaum and Dan Souza from Cook’s Science help us understand the science behind favorite Thanksgiving recipes so you can avoid food failures, and get the most out of your roast and side dishes.      America Has A Food Disparity Problem As of 2016, more than half of American children had a diet that standard nutritional recommendations would consider “poor quality.” And there are stark differences between children in wealthier and poorer households. Poor nutrition can have lifelong impacts on health, including Type 2 diabetes, heart problems, and dental cavities. But it isn’t always clear what families need to provide healthier foods for their children. One popular explanation, now debunked, was the theory of food deserts: Poorer neighborhoods just don’t have grocery stores, and families must buy their food from convenience stores and gas stations. But if more grocery stores aren’t the solution, what is?  Sociologist Priya Fielding-Singh explores these questions in a new book, How The Other Half Eats: The Untold Story of Food and Inequality in America. Her research, the product of months of immersive time spent with families in their kitchens and as they navigated grocery stores with kids in tow, describes an alternative explanation for the socioeconomic disparity between kids’ diets. Fielding-Singh explains healthy food takes emotional and energy resources that lower-income parents must often spend in other ways.  Guest host Roxanne Khamsi talks to Fielding-Singh about her research on family food choices, and the kinds of changes that might allow children from all backgrounds to enjoy healthier foods. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.