Physiological Responses to Basic Tastes for Sensory Evaluation of Chocolate Using Biometric Techniques

Area of Science:

• Sensory Science
• Neuroscience
• Food Science

Background:

• Facial expressions are physiological reactions to basic tastes.
• Understanding autonomic nervous system (ANS) responses to taste is crucial for sensory analysis.
• Objective assessment of taste perception, including emotional responses, is valuable for product development.

Purpose of the Study:

• To evaluate autonomic nervous system (ANS) responses to basic tastes in chocolate.
• To correlate conscious sensory perceptions with unconscious physiological and emotional responses.
• To explore the relationship between taste, liking, and emotional expression in chocolate consumers.

Main Methods:

• Forty-five panelists tasted chocolates with five basic tastes: sweet, salty, sour, umami (monosodium glutamate), and bitter.
• An integrated camera system and Bio-Sensory application captured thermal images, videos, and sensory data.
• Physiological responses (skin temperature, heart rate) and facial expressions were analyzed alongside self-reported emotions and liking.

Main Results:

• Sweet chocolate received the highest liking score (9.01), while salty chocolate received the lowest (3.61).
• No significant differences were found in heart rate (HR) or skin temperature (ST) across tastes.
• Sweet chocolate consumption was linked to positive emotions and inversely associated with anger, while salty chocolate was associated with sadness.

Conclusions:

• Taste preferences for chocolate are significantly influenced by basic taste profiles.
• While physiological measures like HR and ST showed no significant variation, facial expressions and self-reported emotions reflected taste preferences.
• This research provides a foundation for objectively assessing novel chocolate tastes based on integrated conscious, emotional, and physiological responses.