“I thought it was a little strange that they wanted to buy cashew apples — but I didn’t like to question a new source of money,” said Sanjay Pandit, who together with his father, Hanumant Pandit, cultivates about 300 cashew trees in the village of Kondye.

Brazilians are the biggest consumers of the yellow and red apples today; a handful were featured in FIFA’s advertising for the World Cup. But Brazil, a major global source of cashew nuts, processes only about 12 percent of its crop of cashew apples annually because of the challenges posed by their short shelf life, according to research by the African Cashew Alliance, an industry trade group that is also looking for ways to cash in on cashew apples.

Cashew juice also shows up in various local products around the world like Cashewy in Thailand, which is promoted by its producer as “the beverage of gods.” Nutrition and health websites extol its high vitamin C content, and there are even claims that it helps burn fat and enhances sexual performance.

Pepsi stumbled across the fruit in Brazil a few years ago, when Mehmood Khan, its global head of research and development, was working there to get the company’s coconut water business up and running. A local supplier took him to a cashew orchard, where he saw the colorful apples and wondered how they could be used.

The big stumbling block, Pepsi learned, to any commercial use was the fruit’s quick fermentation. “That’s a risk for us — we can’t have Tropicana with alcohol in it,” Mr. Sarma said.

To help improve the farming, collection and rapid processing of the apples, Pepsi turned to the Clinton Foundation, which had expressed interest in the company’s efforts to incorporate small farmers into its global supply chains. Small farmers supply it with chickpeas in Ethiopia and corn and sunflowers in Mexico.

“We work with them to improve cultivation and yields and offer them better prices for their nuts as well as create a market for their cashew apples,” said Govind Ramachandran, general manager of Acceso Cashew Enterprise, the business established by the Clinton Foundation last December to carry out the program in India.