Effect of blow molded type ice cream on autonomic nervous system activity and mental fatigue

Abstract

Currently, consumers expect not only functional value such ascooling but also emotional value such as relaxation or healing when consuming ice cream. In this study, we focused on the effect of blow molded type ice cream on autonomic nervous system activity and mental fatigue. Heart rate variability was employed to assess autonomic nervous system activity. To measure the degree of mental fatigue, the flicker test was performed before and after a simple calculation task, the Uchida Kraepelin Test, for 30 minutes. Next, the flicker test was performed after eating ice cream samples. Subjective assessment of emotional state was also conducted using the Visual Analog Scale (VAS). The difference between maximum and minimum postprandial palmer skin temperatures was calculated using data collected from thermography. As a result, heart rate decreased and parasympathetic nervous activity increased significantly in volunteers who consumed a smooth textured sample. In addition, only the group who consumed a smooth textured sample showed a reduction in subjective fatigue, as calculated from VAS. The hard textured sample showed larger decreases in thermography-measured palmer skin temperature than the smooth texture sample. These results suggested that the smooth textured sample has the highest relaxation effects, and the coolness and smooth texture interacted with each other for a relaxation effect. Furthermore, the refreshing effect of the smooth textured sample was also supported by the results of autonomic nervous system activity and mood states.