ALBANY, Ga. - A federal jury convicted the owner of a peanut plant and two others Friday in connection with a salmonella outbreak that prompted one of the largest U.S. food recalls ever, sickened hundreds across the country and was linked to several deaths.

Experts say the seven-week trial in Albany, Georgia, marked the first time corporate executives and plant workers were tried in a food poisoning case.

In this March 12, 2009 file photo, Peanut Corporation of America's president Stewart Parnell, arrives at United States Federal Court in Lynchburg, Va. AP Photo/Don Petersen

Former Peanut Corporation of America owner Stewart Parnell was convicted on numerous counts including conspiracy, wire fraud and obstruction of justice related to shipping tainted peanut butter to customers and faking results of lab tests intended to screen for salmonella. His brother, Michael Parnell, was also found guilty on multiple charges related to the false lab results, but was acquitted of actually shipping salmonella-tainted food.

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The jury also found Mary Wilkerson, the plant's quality assurance manager, guilty of obstruction of justice for hiding information about the plant's salmonella problems from investigator. But Wilkerson was acquitted on one of two obstruction counts she faced.

All three will be sentenced at a later date. Prosecutor Alan Dasher told the judge the Parnell brothers will likely face prison sentences "well in excess of 10 years," and noted it's possible the middle-aged brothers could remain imprisoned for the rest of their lives. For that reason, he asked the judge to have the Parnells jailed pending sentencing.

"The government's primary concern is about flight risk," Dasher said.

All three defendants have remained free throughout the course of the trial. There was no request to jail Wilkerson before she's sentenced. The judge planned to hear from defense attorneys on the issue later Friday.

Prosecutors accused the Parnell brothers of shipping tainted peanuts and peanut butter five years ago and covering up lab tests showing positive results for salmonella. Peanut Corporation's products were used as ingredients in crackers and other snacks.

The Centers for Disease Control and Prevention found that 714 people in 46 states were infected and nine people died - three in Minnesota, two in Ohio, two in Virginia, one in Idaho and one in North Carolina.

The company's plant in Blakely was shut down after being identified as the origin point of the salmonella outbreak in 2009. Peanut Corporation has since gone bankrupt. Federal inspectors also found roof leaks, evidence of bugs and rodents, and a peanut roaster that workers failed to ensure was heated to the proper temperature to kill salmonella. Investigators say they also uncovered a system the plant used to fake microbiological test results required by customers so the company could conceal positive lab tests for salmonella contamination.

Michael Parnell was in charge of selling tanker trucks filled with peanut paste to Kellogg's, which required 40,000 pounds of paste from Peanut Corporation twice a week. Prosecutors said the Parnell brothers used fake lab results so that wait times for real tests wouldn't slow down their hectic shipping schedule.

After being told a shipment faced delay while waiting on lab results, Stewart Parnell wrote an email referenced several times by prosecutors in the case that read: "Just ship it. I cannot afford to (lose) another customer."

Stacks of emails, shipping records, lab test reports and other documents were introduced as evidence by prosecutors. Two former plant managers - Sammy Lightsey and Danny Kilgore - testified against their former boss and his co-defendants as part of a plea deal reached with prosecutors.

Lightsey testified that he once confronted Michael Parnell about the fake lab tests but allowed the practice to continue after he was told to back down.

"In my mind, I wasn't intentionally hurting anyone," Lightsey testified last month.

CBS News' Paula Reid spoke about the case with Stuart Delery, Acting Associate Attorney General of the United States, who was head of the Civil Division at the Justice Dept. when the Peanut Corporation of America case was brought.

"It is critically important that manufactures know that we will pursue them where they are putting the health and safety of the American consumer at risk," Delery said. He noted that it was a difficult case to prosecute -- the trial went seven weeks with more than a 1000 pages of exhibits.

"Obviously these cases are critically important given that all of us are interested in protecting ourselves and our families. There are a number of things we can do to protect ourselves like wearing a seatbelt in the car, wearing a helmet when we are riding a bicycle," he said. "But we cannot protect the integrity of our food system so we need to be vigilant in enforcing the laws that protect what all of us eat."

Stewart Parnell's lawyers insisted he was unaware of the scale of the Georgia plant's salmonella problem as he tried to manage the company from his home office in Virginia. And attorneys for Michael Parnell noted he didn't work for Peanut Corporation and said he should be considered a customer rather than a conspirator, a middle-man who unwittingly bought tainted peanut paste for Kellogg's. Wilkerson's attorney insisted she cooperated with authorities as best she could.