The analysis was performed at the Lithuanian University of Health Sciences Sensory laboratory, which is equipped with sensory booths. Dark chocolate samples were evaluated by 30 panelists (age from 25 till 50 years, 15 women and 15 men). Mammasse and Schlich [32 (link)] reported that the suitable number of panelists could range from 20 to 150. depending on the level of complexity among test samples. Therefore, it should be noted that a small number of panelists might be a limitation of this study. Chocolate samples were prepared as pieces and presented in four separate serving plates with different codes. The panelist tasted the presented samples one by one in front of a webcam (Microsoft Corporation, Redmond, WA, USA). The tasting procedure was recorded. After tasting each sample, the panelist raised their hand and visualized the taste experience with a facial expression. The time for that was not limited. After that, the panelist was asked to evaluate the overall acceptability of sample using a 10-point hedonic scale, ranging from 1 (extremely dislike) to 10 (extremely like). Between samples, the panelists were asked to rinse the mouth with warm (40 ± 2 °C) water. To evaluate the chocolate-elicited emotions (neutral, happy, surprised, sad, scared, angry, contempt, arousal, disgusted, and valence), the recorded videos were analysed with FaceReader 8 software (Noldus Information Technology, Wageningen, The Netherlands). Only part of video when panelist raise his hand was used for the analysis of chocolate-elicited emotions. The intensity of each emotion was expressed in a scale from 0 (no emotion) to 1 (highest intensity of emotion). The experimental scheme used to evaluate the emotions elicited by different chocolate samples is given in Figure 2 .
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