Food safety officials are looking through Setton Farms' plant in rural Tulare County to see if it could lead them to the source of the contamination.
The recalls began last Friday when the Georgia Nut Company recalled its Kraft Back to Nature Nantucket Blend trail mix after some samples tested positive for salmonella.
Setton Farms has started a separate recall of roasted pistachios, and grocery operator Kroger also has recalled its Private Selection shelled pistachios for possible salmonella contamination.
The packages in question are the ten-ounce containers of Private Selection Shelled Pistachios with a "Sell By" date of DEC-13-09 and DEC-14-09 and a UPC Code of 11110 73615. C
Customers can return these products to Kroger stores for a full refund or replacement.
No illnesses have been reported.