Setton Pistachio expanded its voluntary recall of pistachios to include all roasted shell pistachios and in-shell pistachios due to possible salmonella contamination, the Terra Bella, California, company said on Monday.

The withdrawal from its 2008 crop also would include raw shell pistachios that are not subsequently roasted before sale, the second-largest pistachio processor in the United States said in a statement.

The California processor issued a nationwide recall of pistachios on March 30, a week after one of its customers, Kraft Foods Inc, told U.S. health regulators that its Back To Nature trail mix was contaminated with salmonella and identified Setton as the source.

"The voluntary recall was expanded as a precaution," the statement said.

On March 30, the company announced a voluntary recall of specific lots of bulk roasted shelled pistachios, certain tote bags of roasted in-shell pistachios and Setton Farms brand roasted salted shelled pistachios in 9 oz. film bags.

Setton Pistachio also exports its premium California pistachios to more than 30 foreign markets, according to the company.