Hamburger such as , due to the occasional initial improper preparation of the meat, so caution is needed during handling and cooking. Because of the potential for food-borne illness, the USDA recommends hamburgers be cooked to an internal temperature of . If cooked to this temperature, they are considered well-done. Burgers can also be made with patties made from ingredients other than beef. For example, a "turkey burger" uses ground turkey meat, a "chicken burger" uses ground chicken meat. A "buffalo burger" uses ground meat from a bison, and an "ostrich burger" is made from ground seasoned ostrich meat. A deer
Viktor Hamburger Viktor Hamburger Viktor Hamburger (July 9, 1900 – June 12, 2001) was a German professor and embryologist. In 1951 he co-authored the Hamburger-Hamilton stages. Hamburger lectured, among others, Nobel Prize-winning neurologist Rita Levi-Montalcini, who identified nerve growth factor along with Hamburger when they collaborated. Hamburger began to work at Washington University in St. Louis in 1935; he retired from his professor position in 1969 and continued researching until the 1980s. Hamburger was born on in Landeshut, Silesia, Germany to Max Hamburger and Else Gradenwitz. In the 1960s, Hamburger did embryological work that established that chick movements in embryo were spontaneous