Analysis of Hordeins in Barley Grain and Malt by Capillary Electrophoresis-Mass Spectrometry

Gluten is comprised of a set of wheat, barley, rye, and oat proteins, and it is widely present in the regular diet of the majority of western countries. However, gluten may cause serious health issues, such as celiac disease (CD). In barley, there are four hordein groups: γ-, B-, C-, and D-hordeins. Here, we describe a novel methodology to separate and characterize hordeins in barley grain and malt by capillary electrophoresis-mass spectrometry (CE-MS). Under the optimized conditions, characteristic electrophoretic profiles were obtained using capillaries permanently coated with hydroxypropyl celullose (HPC), after a simple hordein extraction using 50% (v/v) propan-2-ol. Furthermore, different barley proteins were tentatively identified as γ-, B-, and C-hordeins and hordein fragments. The proposed analytical approach demonstrated the potential to rapidly obtain a reliable and enhanced characteristic fingerprint of barley hordeins for quality control of gluten-containing foodstuff.