Ines Thamke1,  K. Duerrschmid2, H. Rohm1

1 Technische Universität Dresden, Institute of Food Technology and Bioprocess Engineering

2 University of Natural Resources and Applied Life Sciences, BOKU Vienna, Department of Food Science and Technology, Division of Food Quality Assurance


Free Choice Profiling tests were carried out to find out whether and to what extent 39 test persons from two different locations (Vienna and Dresden), having the sensory knowledge of the critical consumer, are able to characterize dark chocolate. The cocoa content of the chocolate samples investigated in this study ranged from 60 % to 75 %.  General Procrustes Analysis and subsequent Principal Component Analysis were used for data analysis.

Despite the different local background, both panels used an identical vocabulary for the description of the samples; on average, only five descriptors were elicited from each assessor. Although differently assigned to Principal Components (PC) 1 and 2 which, together with PC3, accounted for approximately 85 % of the total variance, the panels distinguished between the samples on a comparable level. A combined data evaluation revealed that the easily perceivable taste descriptors were useful for sample separation, whereas flavour descriptors only supported these data. With respect to mouthfeeling, chocolate with a lower cocoa content were characterized as melting and creamy, whereas the product with the highest cocoa content was characterized as dry, mealy and sticky.

In conclusion it can be said, that the interested consumer is limited in his vocabulary to describe the sensory properties of dark chocolate. The grouping of the taste and mouthfeeling data showed a distinct relation with the cocoa content of the investigated products. Our data do also indicate that the panellists apply a particular strategy for finding and describing sensory properties. First, they construct a sensory frame of easily perceivable sensory properties which are, in case of chocolate, the basic tastes sweet, sour, and bitter. In a second step, they try to identify further and more subtle properties of aroma and flavour which fit into this frame and which are based on their sensory memory and their actual sensory experience.