WASHINGTON — A failure to adhere to good manufacturing practices by mixing raw and roasted pistachio nuts during processing appears to be at the heart of the Setton Pistachio of Terra Bella, Inc. recall.

David Acheson, assistant commissioner for food protection at the Food and Drug Administration, told the Washington Post the company was apparently aware it had a Salmonella problem because its internal testing found the bacteria on roasted nuts. Managers ran those nuts through the roasting process a second time to kill the bacteria before shipping them to customers. They may have used the same machinery to process the reconditioned product as well as raw product.

As a result, food companies such as Kraft Foods Inc., Northfield, Ill., and Frito-Lay, Plano, Texas, a division of PepsiCo, Inc., have initiated recalls of products containing pistachios. Kraft is recalling both Planters and Back to Nature brand products containing pistachio nuts. The products affected by the recall contain pistachios supplied by Setton Pistachio after Sept. 1.

Frito-Lay is recalling its in-shell, salted pistachios. The affected product is in 1.75-oz packages and has sell-by dates between July 14, 2009, through Dec. 29, 2009.

The Kroger Co., Cincinnati, has expanded the recall of its Private Selection brand shelled pistachios to include those sold in 10-oz containers with sell-by dates of Jan. 14, 2010, Feb. 10, 2010, and March 23, 2010.

The recall could not come at a worse time for the nut industry. Food companies have increased the pace with which they are introducing nut-based snack products. In fact, market researcher Datamonitor named nuts as one of the top trends in packaged goods to watch for in 2009 and noted that snack products are "increasingly going ‘naked’ to showcase nut ingredients."