Contribution of stevia to the perception of sweetness and bitterness in fruit drinks

Abstract

The rise of healthy living trends has increased the popularity of natural sweeteners like stevia, derived from the Stevia rebaudiana plant. This study aimed to examine stevia’s impact on the sweetness and bitterness perceptions of apricot and sour cherry drinks. Initially, fruit drinks with 0% stevia (control group sugar source: saccharose) were produced using an optimal formulation (100 g sugar, 20% fruit puree, 0.3% citric acid, 1 L distilled water) based on Karhan et al.’s experiment (2024). In the earlier panel reviews, a 75% stevia substitution ratio was found to be the best. This study also tested that ratio, and all stevia-substituted fruit drinks (75 and 100%) were made using Karhan et al.'s formula. In the post-production stage, the drinks underwent pH and total soluble solids (Cemeroğlu, 2007), and sensory analyses with panelists (N = 12) using intensity scale (1: Very low, 9: Very high) and ranking (1: Most liked, 6: Least liked) tests (Lawless & Heymann, 2010). Results showed that increasing stevia concentrations decreased the pH values of apricot drinks more than sour cherry drinks. High stevia levels significantly lowered soluble solids in both drinks. Sensory analysis indicated that higher stevia concentrations reduced sweetness perception, especially in apricot drinks, and increased bitterness as sucrose-derived sugar content decreased. This shift in the balance between sweetness and bitterness resulted in a less sweet and more bitter flavor profile. The apricot drink with 0% stevia was the most favored, but the 75% stevia apricot drink also performed well, suggesting effective harmonization with apricot at appropriate ratios. However, drinks totally sweetened with stevia, particularly apricot, were least favored, indicating high stevia doses might adversely affect the authentic taste of apricot. Sour cherry drinks with 100% stevia received slightly better scores than their apricot counterparts. Overall, acceptance of stevia as a sweetener varied by fruit type and concentration. Apricot drinks were preferred more with 75% stevia, while sour cherry drinks were less preferred at the same concentration. The data suggest that stevia can create a favorable taste profile when used in suitable compositions and ratios. In summary, panelists rated sweeter drinks as less bitter, indicating sweetness masks bitterness. The effect of stevia on bitterness was less pronounced in sour cherry drinks, suggesting a better blend with sour cherries. The findings of this study highlight that 20

Uluslararası Tüketici ve Duyusal Bilimler Konferansı Bildiriler Kitabı stevia has good potential when applied in the right proportions. The desired amount of this natural sweetener should be specifically designed for each product. The study also emphasizes the significance of optimizing stevia concentrations to effectively balance sweetness and bitterness. To ensure consumer acceptability, it is essential to maintain this balance, as an excessive amount of bitterness can diminish the overall enjoyment of the drink.