Indra Nooyi served as C-E-O of PepsiCo for twelve years before stepping down last October. Running a packaged goods company just as consumers were starting to demand natural ingredients and healthy alternatives brought its share of challenges. Leading as a woman of color and an immigrant from India, brought another set. Nooyi took the stage at Fortune’s Most Powerful Women Summit to share some of the lessons she learned with moderator Nina Easton.