“…The shelf life is much longer than that of liquid solutions. Although this test has already resulted in a series of publications [14,22,34,36,39] and was proven reliable concerning the investigation of tongue side differences [21,29] and gustatory testing before and after an intervention [30,37], the initially proposed test procedure had some shortcomings. First, the paper by Mueller et al [36] was based on solely 69 observations.…”