The study focuses on potential differences between trained and untrained female subjects with regard to their ability to recognize sweet and bitter. Seventy-six European female students (mean age 22.1) were recruited. They were randomly classified into a control group (n = 35) and an intervention group (n = 41), who were trained. Matching test, intensity testing, and threshold measurements were conducted for all and quantified at t0 (baseline), t1 (after intervention), and t2 (6 months after intervention). The intervention group's performance was enhanced after training: Panelists tended to match more taste samples correctly. Bitter samples were matched better at t1 in comparison with t0. Intensity of sweet and bitter samples was rated higher after intervention, too. The performance was reproduced at t2. Threshold results were ambiguous. Intervention increased the ability to detect tastes. However, in the control group, the recognition thresholds were improved during repeated testing (t1 and t2). The intervention group's performance in perception of sweet and bitter increased because of training. The performance in the control group also improved while the subjects gained experience over the course of the three testing sessions.
The study offers new insight into the effects of sensory training or sensory experiences on the perception of the basic tastes, sweet and bitter. Because many sensory laboratories follow the advice of the International Organization for Standardization (ISO) when conducting sensory training or developing special test designs, the study design was geared to the specifications given in ISO 8586-1 (Sensory analysis – General guidance for the selection, training and monitoring of assessors), and in ISO 3972 (Sensory analysis – Methodology – Method of investigating sensitivity of taste). Of special interest may be the fact that the study focuses on monitoring the effects of training in women over a period of half a year to show how long training effects can last. Training and monitoring of sensory panelists is time consuming and expensive. Simplifying the procedures would be advantageous for panel leaders as well as for the panelists themselves.