COMPROMISED ACCEPTANCE THRESHOLD AND HEDONIC REJECTION THRESHOLD TO DETERMINE THE CONCENTRATION OF BEET (Beta vulgaris L. var. rubra) IN YOGURT

Beet is a vegetable rich in betalains, pigments responsible for their purple color and high antioxidant activity. However, its earthy flavor and aroma make this food share opinions about its acceptance and consumption. Yogurt is a versatile and popular product among consumers, being a great vehicle for consuming beet. The objective of this work was to determine the maximum concentration of beet that could be used in the preparation of beet yogurt, by using the Hedonic Threshold Methodology, which was applied to determine the Compromised Acceptance Threshold (CAT) and the Hedonic Rejection Threshold (HRT). Consumers participated in five acceptance sessions, where, in each session, two samples were served; one was the control sample (5% beet) and the other was one of the stimulus samples (five different beet concentrations, from 5.5% to 24%). The CAT was determined applying a paired t-test, using the hedonic scores of the control and stimulus samples in each session. From the t-values obtained, a graphic of the t-value of each session was plotted as a function of the beet concentration in the stimulus samples. The concentration at which a significant difference in acceptance between samples begins to occur (CAT) was determined by adjusting a regression model to the data. The HRT was determined by inserting a second axis in the same graphic, referring to the mean hedonic score of the stimulus samples. A regression model was adjusted to these data. The HRT was calculated, with the concentration of beet addition corresponding to the point at which the mean hedonic score becomes 5. A total of 87 consumers who like beet (LB) and 76 consumers who dislike beet (DB) participated in this analysis. From the determination of CAT and HRT for each of the two consumer groups, a final formulation of beet yogurt was chosen. CAT = 6.71% and HRT = 20.14% of beet were found for the LB group and CAT = 7.15% and HRT = 10.27% for the NGB group. Based on these results, the concentration of 6.71% of beet in yogurt was set as the one that would satisfy a greater number of consumers.