OAKLAND, CALIF. — Marie Callender’s Pie Shops, Inc. has become the latest target of lawsuits seeking damages for alleged misleading advertising, marketing and labeling of “all natural” products.

A class action suit filed by Edward Musgrave and a national class of consumers on May 1 in the U.S. District Court for the Northern District of California claims the Mission Viejo, Calif.-based company engaged in the “unfair, unlawful, deceptive, and fraudulent practice of describing and falsely advertising certain products as ‘all natural’ when, in fact, they contain the synthetic substance sodium acid pyrophosphate.”

According to the filing, sodium acid pyrophosphate is an odorless white powder that has various applications, including use in leather treatments and for feather removal from birds in poultry slaughter. The lawsuit states that Marie Callender’s uses sodium acid pyrophosphate in all its all natural products, and “not only is SAPP a synthetic product, but excessive use can lead to imbalanced levels of minerals in the body and bone loss.”

Additionally, sodium acid pyrophosphate is a leavening acid that is only partially soluble in cold water, suiting it to use in cold batters and refrigerated doughs, according to the fourth edition of Baking Science & Technology, published by Sosland Publishing Co. Efforts to reduce sodium in products have included finding replacements for SAPP.

The products at the center of the complaint include six items sold under the Marie Callender’s brand: original corn bread mix, corn bread muffin mix, all purpose biscuit mix, sweet potato muffin mix, honey butter corn bread and muffin mix, and multigrain muffin mix. The bread and muffin mix products subject to the lawsuit are not owned or made by ConAgra Foods and have no affiliation with the company’s Marie Callender’s brand frozen meals and pies, Omaha-based ConAgra said.

“Defendant’s advertising/labeling of these products as ‘all natural’ is false, dishonest and intended to induce consumers to purchase these products, at a premium price, while ultimately failing to meet consumer expectations,” the lawsuit states. “Defendants know reasonable consumers must and do rely on defendants to honestly report the nature of their products’ ingredients, insofar as consumers lack the ability to test or independently ascertain the accuracy of a food product’s label, especially at the point of sale. Defendants played on consumer ignorance to fraudulently generate substantial profits and engender unfair competition between themselves and competitor companies that, unlike defendants, behave responsibly and honestly toward their customers.”

According to the lawsuit, the plaintiffs purchased the items at least 18 times over the past three years, relying on the truthfulness of the label that promised that the products were “all natural.”

Marie Callender’s did not respond to requests for comment from Food Business News.

Companies making all natural claims increasingly have come under fire in recent years and have been the subject of several lawsuits. PepsiCo, Inc., Purchase, N.Y., in July 2013 removed the phrase “all natural” from the labels of its Naked juices after a lawsuit was filed in the U.S. District Court of California. PepsiCo agreed to pay $9 million to settle. More recently, H.J. Heinz in March was sued by a consumer claiming the company’s distilled white vinegar is not “all natural” because the product is made with bioengineered crops, namely corn.

Katherin “Barr” Hogen of Barr-None Consulting in Boulder, Colo., last winter told Food Business News that she has advised her clients not to make all-natural claims on the front of their products.

Choose an alternative way to promote your product instead. Ms. Hogen said she works for start-up companies who cannot afford to be sued, which lately has become a more frequent occurrence for all-natural claims.