A Costco customer has filed a proposed class-action lawsuit against the retailer, alleging that its Kirkland Signature Five Cheese Tortelloni with Parmigiano Reggiano is falsely marketed as preservative-free. The complaint, lodged by Sydney Turner in a California federal court on April 29, claims the product contains manufactured citric acid, which acts as a preservative.
According to the legal documents, the front of the packaging prominently states 'no preservatives,' but the ingredient list includes citric acid produced through industrial fermentation using a genetically modified black mold, Aspergillus niger. Turner argues that this citric acid is not naturally derived from fruit and serves as a chemical preservative.
Turner purchased the frozen tortelloni in December 2023, relying on the marketing claim. She asserts she would not have bought the product, or would have paid less, had she known about the additive. The lawsuit seeks class-action status for consumers nationwide and in several states, demanding damages, fees, costs, and a jury trial.
The case follows another class-action suit against Costco filed in March, which accused the retailer of retaining financial benefits from federal import tariffs that were later struck down by the U.S. Supreme Court. That dispute involved duties imposed in February 2025, with Costco raising prices on imports but failing to refund customers after the tariffs were ruled unlawful in February 2026.
