Optimisation of the partial napping approach for the successful capturing of mouthfeel differentiation between brandy products

Partial napping has been validated as a suitable sensory profiling method for brandy evaluation. However, it was found that, compared to conventional profiling, very little useful information could be extracted on brandy mouthfeel when it was evaluated as part of overall in-mouth perceptions. This study aimed to optimise the partial napping method to improve information output on the mouthfeel of brandies. Panellists’ proficiency in visual, aroma and in-mouth evaluation of brandies were scrutinised after which three partial napping protocols were tested to identify the most effective solution for the successful capturing of mouthfeel differences between brandies. The results showed that panellists were equally efficient in aroma and in-mouth evaluations, but that in-mouth perception (defined as retronasal flavour, basic taste and mouthfeel) was not a useful construct as it did not contribute to the product configuration that could be obtained with visual and colour assessments alone. Instructing panellists to ignore retronasal flavour delivered more useful results. Using dark glasses and nose-clips to eliminate visual, aroma and retronasal flavour perceptions were not necessary to obtain a reliable and interpretable representation of the mouthfeel differences between brandies. Clear glasses and written instructions were sufficient to generate useful mouthfeel information under conditions more representative of the consumer product experience.