ac7b04371_si_001.pdf (2.2 MB)
Analysis of Gluten in a Wheat-Gluten-Incurred Sorghum Beer Brewed in the Presence of Proline Endopeptidase by LC/MS/MS
journal contribution
posted on 2018-01-12, 00:00 authored by Katherine L. Fiedler, Rakhi Panda, Timothy R. CroleyMost
gluten-reduced beers are produced using an enzyme called proline
endopeptidase (PEP), which proteolyzes the gluten by cleaving at proline
residues. However, the gluten content of beers brewed in the presence
of PEP cannot be verified since current analytical methods are not
able to accurately quantitate gluten in fermented foods. In this work,
mass spectrometry was used to qualitatively characterize the gluten
in a wheat-gluten-incurred sorghum model beer brewed with and without
the addition of PEP. Hydrolyzed gluten peptides and chymotryptic gluten
peptides produced from intact gluten proteins were detected in beer
brewed in the presence of up to 6 times the manufacturer’s
recommended dosage of PEP. The observation of chymotryptic gluten
peptides indicates that some gluten proteins remained, at least partially,
intact after fermentation and enzymatic treatment. Less intact gluten
was observed in beer brewed in the presence of PEP, but more hydrolyzed
gluten peptides were consequently observed in PEP-containing beer.
Gluten peptides that contained immunogenic sequences known to be associated
with celiac disease were detected in PEP-containing beer.