Gluten Testing of Food Containing Barley Amylase: Poster Presented at AOMSC 2023

To download the poster presented at the Asia-Oceania Mass Spectrometry Conference, please see: https://www.glutenfreewatchdog.org/news/wp-content/uploads/2024/01/PosterAOMSC20230703_AO-MSC_MN_Poster.pdf

AOMSC 2023 Poster Abstract

Investigation of foods containing beta-amylase for gluten content

Mitchell G. Nye-Wood (a), Tricia Thompson (b), Margaret Clegg (b), Michelle L. Colgrave (*a)

School of Science, and Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Edith Cowan University, Perth, WA, Australia (a)

Gluten Free Watchdog, LLC, Manchester, MA (b)

Gluten proteins are unique food allergens that are a common dietary component for many people but cause inappropriate immune reactions in susceptible people. They occur in wheat, barley, and rye, and safety claims regarding food gluten content varies by jurisdiction. In the USA, barley is not a major allergen under the Food Allergen Labeling and Consumer Protection Act, so can be declared in an ingredients list simply as amylase. Amylase is used in some food products to hydrolyze starch or polysaccharides to change texture and sweetness. However, if it arises from barley, there remains the possibility that it contains barley gluten proteins known as hordeins. Bacteria or yeast food products cultured on gluten-positive media typically contain some level of gluten content. If amylase is obtained from barley, or from related gluten-positive cereal grains, its gluten content will entirely depend upon the efficacy of the purification steps employed in its preparation.

We surveyed the gluten content of seven products known to contain amylase, including wet and dry noodles, a rice milk imitation drink, and capsules of purified barley amylase powder. Wheat and malted barley were used as positive controls. Competitive ELISA was used in accordance with the manufacturer’s instructions, and multiple reaction monitoring liquid chromatography-mass spectrometry was used to detect trace levels of gluten content. Samples were prepared using both trypsin and chymotrypsin as proteolytic enzymes and analysed using multiple reaction monitoring mass spectrometry to target high-responding gluten peptides from both wheat and barley. While wheat and barley contained expected levels of gluten content, no gluten was detected in the rice-based food products or purified amylase. While batch-to-batch variation may exist, products that contained purified barley amylase did not provide evidence of gluten presence.