The number of US food makers linked to the HVP salmonella scare continues to grow, although food safety officials insist that there have been no cases of illness linked to the recall.

Homemade Gourmet, a maker of soup mixes, dressings and dip maker Reser's Fine Foods and tofu firm Earth Island are the latest companies to recall products, according to the US Food and Drug Administration (FDA).

The Reser's Fine Foods recall prompted retail giant Safeway Inc to yesterday (4 March) issue its own announcement covering products supplied by the manufacturer.

The source of the salmonella is HVP, or hydrolyzed vegetable protein, made by Nevada-based Basic Food Flavors.

A customer of Basic Food Flavors notified the authorities of the contamination through the recently-created US "Reportable Food Registry". An FDA investigation then identified salmonella at the production site.

Basic Food Flavors has issued a voluntary recall of all powder and paste HVP made since 17 September last year.

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

HVP is an ingredient used as a flavor enhancer in many food products from soups and stews to hot dogs and snack foods.

However, the FDA has moved to assuage industry and consumer concerns by pointing to the "small levels" of HVP in processed foods.

The FDA also insisted the salmonella would be either killed by food processors when making the foods or by consumers when cooking at home.

Nevertheless, the regulator claimed the incident has emphasised the need to bolster its power.

“This situation clearly underscores the need for new food safety legislation to equip FDA with the tools we need to prevent contamination," said Dr. Jeff Farrar, associate commissioner for food protection, at the FDA’s office of foods.