 Using both her local and technical knowledge, Orosa made culinary contributions and taught proper preservation methods for native dishes such as "adobo, dinuguan, kilawin" and "escabeche".During World War II, Orosa used her food science background to invent Soyalac (a protein-rich powdered soybean product) and Darak (a rice bran powder rich in thiamine and other vitamins which could also treat beri-beri).She also became a captain in Marking's Guerrillas, a Filipino guerrilla group organized by Marcos "Marking" V. Augustín.