Soryan took the world and Asian titles last year, but will face some strong competition from Eun-chol Park of South Korea, who has won two world silver medals and a world bronze medal in the last three years.
Cuba's Yagniel Hernandez won the 2007 Pan American Games and 2008 Pan American Championships in this weight and will fancy his chances along with 22-year-old American Spenser Mango.
In the featherweight, 60kg category, Georgia's David Bedinadze looks a strong contender having won the world title in 2007 and finishing second this year.
Two-time Olympic gold medallist Armen Nazarian of Bulgaria remains, despite being 34, a serious contender.
He won gold in the 48-52kg category competing for Armenia in Atlanta in 1996 and then again four years later for Bulgaria in the 54-58kg and also claimed a bronze in that weight in Athens.