The results of the present study show that cats performed behaviors indicative of a pleasant taste experience whilst sampling L-Proline at 50 and 500 mM. During Experiment 1, the cats were observed to differ significantly between L-Proline and water in behaviors such as: sniffing at the spouts, eyes less than 50% open, tongue protrusions, nose licks and mouth smacks.

In Experiment 2, significant differences in the behavior of the cats between QHCl and water included; the occurrence of tongue protrusions and tongue protrusions gapes. A preference for solutions of L-Proline without the addition of QHCl was observed during Experiment 3.

Only with the strongest concentration of L-Proline at 500 mM in the mixture with 50 µM QHCl was there no significant difference in how often the cats licked at the spouts between the mixture and the 50 mM L-Proline control. However, no masking effect for L-Proline could be confirmed as rather thanthe cats starting to accept the mixture, they instead decreased in the number of times they licked at the spout containing the control. The cats were observed to differ significantly between the L-Proline and QHCl mixtures and the L-Proline control in behaviors such as: eyes less than 50% open and tongue protrusion gapes.