Phytochemical characterization and sensory acceptability of sweet herbal tea blend I: moringa, yerba mate, and chamomile

This study aimed to investigate sweet herbal tea blends commonly consumed in South American countries, focusing on sensory acceptability, sweetening properties, and phenolic compounds with antioxidant potential. The infusion blends studied included stevia (ST), yerba mate (YM), manzanilla (CH), and moringa (MO), in various combinations and proportions. MO from summer and winter harvests was used. Radical scavenging activity ranged from 10.3 to 42.8 µg/mL, from ST : YM to MO : CH infusions. Infusions prepared with summer-harvested MO showed significantly higher antioxidant activity (p < 0.001). Most blends exhibited synergistic effects on in vitro radical scavenging activity, although MO : YM and MO : ST : YM showed antagonistic interactions. Total phenolic content varied from 58.6 to 118.6 mg GAE/g DE, from MO : CH to ST. The content of steviol glycoside sweeteners increased proportionally with the amount of ST in the blends. In general, the recovery of sweeteners and antioxidant compounds followed distinct patterns, but a strong correlation was found between total flavonoids (as quercetin equivalents) and radical scavenging activity. Sensory evaluation showed that the proportion of ST (1:1 vs 1:3) had little effect on acceptability, aroma, or perceived sweetness. Hedonic scale scores ranged from 6.5–7.0 for flavor, 6.0–6.4 for sweetness quality, and 4.4–6.1 for sweetness intensity, evaluated on an unstructured scale; MO : ST : CH had the lowest sweetness score. Sensory perception varied mainly by sex and ST consumption habits. An ST concentration of 0.67–1.0 g per infusion was considered acceptable. These findings suggest that sweet herbal tea blends may offer a healthy, naturally sweet alternative to traditional herbal infusions.