Caracterización de patrones de hordeínas en variedades mexicanas de cebada maltera

Abstract

A group of storage proteins highly abundant in cereal seeds are the prolamins, characterized by the frequent presence of proline in their sequence. The barley prolamins are known as hordeins. The aim of this study was to obtain the hordein banding patterns for five different Mexican barley cultivars in mature seeds. In addition, the hordein patterns in processed malt of four mexican and a canadian (Metcalfe) barley cultivars were obtained. Mass Spectrometry (MS), using distinct digestion protocols, identified differential bands in the patterns. Major differences in the seed patterns between cultivars consisted in discrete bands at 100 kDa, 65 kDa and in the range of 37 to 45 kDa. In malt, the patterns were highly contrasting among Mexican cultivars as well as in Metcalfe, suggesting that hordein processing during germination and malt processing is particular to each cultivar. Finally, the MS identification demonstrated that trypsin digestion is appropriate to distinguish B and γ hordeins in malt, whereas sequential digestion with chymotrypsin and trypsin allows the identification of C hordeins in seed.