In 1946, after Unanue returned home, he enrolled in The Catholic University of America in Washington, D.C., where he graduated with a degree in Mechanical Engineering. He joined the family business, together with his brothers Tony and Frank Unanue. He learned every facet of the food industry. At first, the major supermarkets, such as A&P and Safeways weren't interested in selling anything with the Hispanic demography in mind. Eventually, with the wave of Hispanic immigrants landing in the United States, the supermarket industry started to take notice. Goya Foods started to supply Safeway's Supermarket in Harlem and the rest soon followed.