Visualization of α-Amylase Movement and Cell Wall Breakdown during Barley Malting—Practical Application of Current Research

Two of the main events occurring during barley malting are the de novo synthesis and transport of α-amylase and the breakdown of the endosperm cell walls, which are rich in β-glucans. A monospecific antibody was raised against the isoenzyme group of α-amylase produced de novo during germination. It was thereby possible to follow the synthesis and transport of the α-amylase protein moiety immunohistochemically rather than following “amylase activity,” which may be influenced by other factors. Following α-amylase localization, the sections were further treated with Calcofluor™, thus effecting a fluorescent staining of the major endosperm cell wall components. Optimized exciter and barrier filters and a new macrofluorescence microscope unit were developed to observe α-amylase and cell walls. The new method provides an accurate determination of the physiological stage of the germinating seeds. The synthesis and transport of α-amylase and the breakdown of the β-glucan-rich endosperm cell wall material were studied in maltings at the Carlsberg Breweries, and the results are compared with classical malt analyses.