During World War II, Orosa joined Marking's Guerrillas to fight for Philippines freedom. She invented over 700 recipes during her lifetime, including Soyalac and Darak, which saved thousands of lives during the war. She also invented a process for canning goods for the guerrilla warriors fighting for the liberation of the Philippines. Without her food inventions, thousands of people would have died in internment camps, hospitals, and on the streets.