Food Structure


Development of (1,3;1,4)-B-D-glucan and (1,3)-B-D-glucan in kernels of Himalaya and Bonanza barley has been followed by fluorescence microscopy using calcofluor and aniline blue fluorochromes. Specific enzymes were used to confirm the identity of these two polysaccharides in sections of endosperm tissue. All barley lines tested contained both types of B-glucan but (1,3;1,4)-B-glucan was synthesized at an earlier stage of development than was (1,3)-BGlucan. Small bead-like deposits of (1,3)-B-glucan were detected in all cultivars examined. These deposits were present throughout the endosperm and appeared to be associated with the inner walls of endosperm cells. After treatment of sections with (1,3)-B-glucanase, these deposits could not be detected with aniline blue. Himalaya barley contained, in addition to these bead-like deposits, larger deposits of (1,3)-B-glucan that appeared to be associated with the inner surface of the cell walls of the outermost cells of the starchy endosperm, The deposits were concentrated at the aleurone-endosperm junction and those present in immature kernels were susceptible to hydrolysis by (1,3)-B-glucanase. Enzymic analysis indicated that, in mature Himalaya kernels, the large deposits also contained (1,,3;1,4)-B-glucan and the other material of, as yet, unknown identity.

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