ABSTRACT

Early work by E. Kneen and R. M. Sandstedt demonstrated the existence of soluble proteins in wheat and rye flours that inhibited alpha-amylases. These and similar inhibitors from other species are active against mammalian and some bacterial alpha-amylases but have no action against higher plant alpha-amylases. Heat stable inhibitors of cereal alpha-amylases have been reported in durum and winter wheat and maize kernels. The inhibitor protein is distributed throughout the mature barley endosperm. It is also present in the aleurone and embryo. Concentrations of the inhibitor vary widely amongst barley cultivars and comprise from 0.3 to 1.3 per cent of the seed protein. The physiological function of the inhibitor protein remains an enigma. According to L. Mttnck et al., who looked at variation in alpha-amylase inhibitor levels amongst barley cultivars of differing degrees of dormancy, there is no correlation between pregermination incidence and level of alpha-amylase inhibitor.