Stewart Parnell, 61, who once oversaw Peanut Corporation of America, and his brother, Michael Parnell, 56, who was a food broker on behalf of the company, were convicted on federal conspiracy charges in September 2014 for knowingly shipping salmonella-tainted peanuts to customers.
Contamination at the company's plant in Blakely, Georgia, led to one of the largest food recalls in US history and forced the company into liquidation.
US District Judge Louis Sands gave Michael Parnell 20 years in prison. Mary Wilkerson, 41, a former quality control manager at the plant who was found guilty of obstruction, was sentenced to five years in prison.
Stewart Parnell faced life in prison and his brother faced about 24 years.
The Justice Department described Stewart Parnell's sentence as the largest in a food safety case.
Before the judge issued the sentences, Stewart Parnell said; “This has been a seven-year nightmare for me and my family. I’m truly, truly sorry for what’s happened.”
At Monday's hearing in Albany, Georgia, the relatives of several victims described their suffering and asked for stiff sentences.
Jeff Almer, of Brainerd, Minnesota, said his mother, Shirley Almer, died after eating tainted peanut butter in 2009.
"My mother died a painful death from salmonella, and the look of horror on her face as she died shall always haunt me," he said.
"I just hope they ship you all to jail," Almer said.
During the seven-week trial last year, prosecutors said the Parnell brothers covered up the presence of salmonella in the company's peanut products for years, even creating fake certificates showing the products were uncontaminated despite laboratory results showing otherwise.
The Parnells have said they never knowingly endangered customers, and their supporters asked a judge on Monday to show mercy.
"No one thought that the products were unsafe or could harm someone," said Stewart Parnell's daughter, Grey Parnell. "Dad brought them home to us. We all ate it."
An official with the Centers for Disease Control and Prevention testified at the trial that the company's peanut products sickened 714 people in 46 states, including 166 of whom were hospitalized.
