Analysis of Gluten in Dried Yeast and Yeast-Containing Products

• Main Authors: Laura K. Allred, Mitchell G. Nye-Wood, Michelle L. Colgrave
• Format: Article
• Language: English
• Published: MDPI AG 2020-12-01
• Series: Foods
• Subjects: gluten; yeast; LC–MS; ELISA
• Online Access: https://www.mdpi.com/2304-8158/9/12/1790

Yeast are commonly used in the preparation of foods and beverages such as beer and bread and may also be used on their own as a source of nutrients and flavoring. Because of the historical connection of yeast to products made from wheat and barley, consumers maintaining a gluten-free diet can have concerns about the safety of yeast ingredients. Analyzing the safety of yeast and yeast-containing products presents some difficulties, as the yeast organisms actively degrade any gluten in the product, raising questions on the appropriateness of detection by traditional antibody-based methods. This study examines a variety of yeast and yeast-containing products by competitive ELISA and liquid chromatography-mass spectrometry for the estimated level of gluten proteins. While samples such as yeast extracts and nutritional yeast contained gluten levels below the 20 mg/kg (or parts per million, ppm) threshold defined by Codex Alimentarius, one baking yeast and a nutritional yeast supplement sample contained higher levels of gluten. This study demonstrates that both competitive ELISA and liquid chromatography-mass spectrometry provide similar results in the detection of wheat and barley gluten in yeast-containing products.