Generous Brands, a portfolio company of private equity firm Butterfly, has announced that it has signed an agreement to acquire California-based soft drinks firm Health-Ade from fellow equity funds First Bev and Manna Tree Partners . Founded in 2012, Health-Ade positions itself as a producer of “feel-good, bubbly beverages” with gut-health benefits, including kombucha, prebiotic sodas and cocktail mixers. The company has annual retail sales of $250 million and its …