The list of processed foods being recalled because of salmonella fears continues to grow as authorities in Canada and the U.S. track down tainted products.

The massive investigation comes after the discovery that a widely used food additive, hydrolyzed vegetable protein, known as HVP, may have been contaminated by salmonella at a Las Vegas factory that makes it.

HVP is a flavour enhancer used in thousands of food products, such as soups, sauces, chilies, stews, hot dogs, gravies, seasoned snack foods, dips and dressings. It is often blended with other spices to make seasonings that are used in or on foods.

Basic Food Flavors Inc. of Las Vegas initiated the recall Saturday after the U.S. Food and Drug Administration conducted an investigation and found traces of Salmonella tennessee.

In the U.S., 101 products have been identified as containing HVP made by Basic Food Flavors.

In Canada, the list includes 26 products, including President's Choice pretzels, some flavours of Kettle Style chips and both President's Choice and No Name dried soup mixes.

Both the Canadian Food Inspection Agency and the Food and Drug Administration are continuing to investigate and will update the list of recalled products as potentially contaminated items are identified.

Unfortunately, children could be more at risk of being stricken by the bacteria because of the types of foods being recalled, says one expert.

"Snack foods are often consumed by children, who are unfortunately a little more susceptible to infection than a healthy adult," Kevin Allen, a microbiologist at University of British Columbia, said in an interview with CBC News.

So far, no illnesses have been reported in either the U.S. or Canada.

"Our investigators were able to identify this problem before any illnesses occurred," FDA commissioner Dr. Margaret A. Hamburg said this week in a release. "While the investigation is continuing, the agency is supporting reasonable steps to continue to protect the public health."

Basic Food Flavors initiated the recall of all HVP in powder and paste form produced since Sept. 17, 2009, after the FDA collected and analyzed samples at the facility. It confirmed the presence of salmonella in the company's processing equipment.

Food contaminated with salmonella may not look or smell spoiled. Consumption of food contaminated with these bacteria may cause salmonellosis, a food-borne illness.

In young children, the elderly and people with weakened immune systems, salmonellosis may cause serious and sometimes deadly infections. In otherwise healthy people, salmonellosis may cause short-term symptoms such as high fever, severe headache, vomiting, nausea, abdominal pain and diarrhea.

With files from The Canadian Press