Understanding consumer liking for sustainable products: insights from EsSense25 and the Emotional Index

Rapid population growth and resource depletion necessitate exploring sustainable food solutions, and brewery spent grain (BSG), rich in fiber, presents a promising approach. This study investigated consumer acceptance of BSG-enriched bread, pasta, and chocolate milk combining explicit self-reported and implicit physiological measures of emotional states. For the explicit measures, 100 consumers rated product liking and completed the EsSense25 questionnaire; while for the implicit measures, 30 participants underwent psychophysiological measurements with a Shimmer3 GSR system to record Galvanic Skin Response (GSR) and heart rate (HR) for each product, which were used to calculate the Emotional Index (EI). Results showed BSG's impact on liking was product-dependent. "Satisfied" and "interested" correlated positively with liking, while "disgusted" and "bored" correlated negatively. PCA revealed distinct emotional profiles for BSG-enriched pasta. Regression models identified "disgusted" and "satisfied" as key liking predictors. The EI was higher during tasting, but didn't correlate significantly with liking. This study shows partial value in integrating traditional hedonic and emotional factors into sustainable food product development, demonstrating the feasability of combining conventional sensory methods with techniques like the EI and EsSense25 to deepen understanding of consumer acceptance, although EI showed only weak alignment with liking.