Mmmm, chips. One of the most sublime of salty snacks. But have you ever wondered how they get that perfectly salty sheen on the outside?
 
"Salt is sprayed on the surface." Youngsoo Lee is a food engineer at the University of Illinois Urbana–Champaign. And he says not all salty foods are created equal. There's spray-on surface salt. There's salty liquids, like canned soup. And then there are salty solids, where the sodium is dissolved in a matrixlike structure. Think: salamis and cheeses. But when we eat those salty solids, only a fraction of the salt gets released before we swallow. Meaning a lot of that salt has no effect on taste—but a big effect on our daily salt intake.
 
Lee's investigating that salty-solid conundrum for a company that wants to make cold cuts that taste the same but contain less salt. He couldn't tell me which one. "Um... I mean, it's a fairly big U.S.-based food company."
 
To find a salty solution he and his colleagues created blocks of whey protein with various proportions of fat, water and salt. Then they squashed those tofulike blocks underwater, to measure how much sodium the blocks released. Turns out, the bigger and more numerous the pores within the blocks' protein structure the more salt that was released. The study is in the Journal of Food Science. [Wan-Yuan Kuo and Youngsoo Lee, Temporal Sodium Release Related to Gel Microstructural Properties—Implications for Sodium Reduction]
 
Lee didn't actually have taste-testers sample different types of pore-filled blocks—that’s next. But previous studies have shown that airier, fluffier breads do indeed taste saltier to testers. And there's one other trick this study uncovered: solid foods release more of their embedded salt over time. So next time you're about to ask for the salt, why not just spend a little more time chewing instead?
 
—Christopher Intagliata
 
[The above text is a transcript of this podcast.]