Barley and their hybrids and derivatives, barley contains gluten, which makes it an unsuitable grain for consumption by people with gluten-related disorders, such as celiac disease, non-celiac gluten sensitivity and wheat allergy sufferers, among others. Nevertheless, some wheat allergy patients can tolerate barley or rye. Barley is a key ingredient in beer and whisky production. Two-row barley is traditionally used in German and English beers. Six-row barley was traditionally used in US beers, but both varieties are in common usage now. Distilled from green beer, whiskey has been made primarily from barley in Ireland and Scotland, while other countries have used
Gluten immunochemistry include: LTP (albumin/globulin), thioredoxin-hB, and wheat flour peroxidase. A particular 5 residue peptide, Gln-Gln-Gln-Pro-Pro motif, has been found to be a major wheat allergen. New immunogenic motifs appear in the literature almost monthly and new gliadin and "Triticeae" protein sequences appear that contain these motifs. The HLA DQ2.5 restricted peptide "I I Q P Q Q P A Q" produced approximately 50 hits of identical sequences in NCBI-Blast search is one of a several dozen known motifs whereas only a small fraction of Triticeae gluten variants have been examined. For this reason the immunochemistry is best discussed at the level