"The mouth doesn't anticipate the combo, which actually makes it more pleasurable to the brain," says food scientist Steven Witherly. "If something looks like a Cheeto but tastes like a Pepsi, it wakes up the brain."
The fizzing Pepsi-flavored Cheetos hit shelves last month in Japan, where no flavor combination is too wild.
One reviewer said the sensation was acidic, and that the effort to hit Pepsi's recognizable citrus notes went too far, overpowering the more subtle flavor of sweet cola. Even so, she said, "I'd eat a handful."
Frito-Lay spokesman Jeff Dahncke says they'll only be available for a limited time, however, and there are currently "no plans" to bring the fizzing Cheetos to the U.S.
But there is no shortage of flavor mash-ups in the U.S., where some 20,000 new food and drink products are introduced each year.
Taco Bell has used three different Doritos flavors for its taco shells, for example, and other brand names are working just as hard to churn out novelty products.
Even mouth surprise gone wrong benefits brands, as the "ew" factor still prompts consumers to post about their gross-out experience to social media sites like Facebook and Twitter, where their friends may decide they want to see how gross it can really be.
Mouth surprise "speaks to consumers' short attention spans," according to one new products researcher at Mintel. "Consumers all want something absolutely new that's never been seen before."