Diet Pepsi executives quietly changed its sweeteners so it would taste better for longer.
"In addition to aspartame, cans of Diet Pepsi found in New York, Omaha, Neb., and the Bay Area now list acesulfame potassium as an ingredient," reports the Associated Press.
"Cans of Diet Pepsi around the country now list a mix of two artificial sweeteners, a pairing that is commonly found in newer diet sodas," according to the story. "Previously, Diet Pepsi used only aspartame, which is sensitive to heat and breaks down more easily."
The new product started rolling out earlier this month and will slowly infiltrate stores, a spokesperson for the brand said. Next month, Diet Pepsi will get a major rebranding, with a new heart logo and a "Love Every Sip" motto.
An expert told the AP that the flavor of Diet Pepsi wouldn't change, but that it would be able to stay fresh for longer.
The ingredient-change is another step in Pepsi's mission to gain back market share from Coke.
Coca Cola is the most popular beverage in the world. Diet Coke overtook Pepsi as the second-most-popular drink back in 2010.
Diet Pepsi is the 7th most popular soft drink.
Pepsi has had an ambitious marketing year. It inked a deal with Beyonce, bought a multi-year Superbowl halftime sponsorship and launched new ads with Modern Family actress Sofia Vergera.
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