Dr. Castillo's research interests include the development of control measures for minimizing and reducing pathogens in fresh and fresh-cut food products, the bacterial reduction on beef and pork products and fresh produce by sanitizing rinses and the use of electron beam irradiation for food safety purposes. He has published numerous articles in peer-reviewed journals, has authored or co-authored six book chapters and has published two books as editor. He teaches the graduate course in Microbiology of Foods and co-teaches the HACCP stacked course.