Effects of Pregermination on Germination Properties of Barley and Resultant Malt Quality

Abstract

A simple and easily workable method for assessing pregermination in barley relies on microscope-assisted examination of tetrazolium-stained bisected embryos from the rapid germinative capacity test. Growth of root and/or shoot that extends beyond the confines of the embryo area is taken to be a positive indicator of unacceptable pregermination. The method proved practical at barley intake points without adding significantly to the workload. Using the procedure, barleys containing various levels of pregerminated corns were selected, as were appropriate non-pregerminated controls. Dried barleys were stored in the laboratory at 15°C for 42 weeks and buried in a bulk bin for 26 weeks. Samples were tested for germinative energy at monthly intervals and micromalted after longer intervals to determine the effects on malt analysis. Pregerminated barleys lose germinative energy in storage, with death of some pregerminated corns, take up more water during steeping, produce mold during germination, and produce malts of progressively inferior quality, depending on the level of pregerminated corns present.