Sensory Characterization of Licorice Extract in Formulated Spirits and the Intervention of Puerarin on Sweetness Lingering

Glycyrrhizic acid (GA), a high-potency natural sweetener derived from licorice, has long been limited in alcoholic beverages due to its characteristic lingering sweetness in both aqueous and ethanol matrices. From an industrial perspective, licorice extract offers superior economic viability and processing efficiency compared to high-purity monomers. To clarify the sensory behaviour of licorice extract in formulated spirits, this study characterized the sensory attributes of licorice extract (containing 23.75% GA) in 42% and 52% vol base spirits. Quantitative results showed that the detection thresholds, recognition thresholds, and upper limits of comfort were 2.23, 15.45, and 75.13 mg/L in the 42% vol base spirit, and 5.28, 25.64, and 72.98 mg/L in the 52% vol base spirit, respectively. Suitable addition levels were identified as 30 mg/L for 42% vol and 40 mg/L for 52% vol base spirits. The relative sweetness of GA was determined to be 175.83 times that of sucrose. Sucrose showed a sweetness duration of 10 to 12 s, whereas licorice extract exceeded 16 s. Puerarin showed the strongest effect in mitigating lingering sweetness, reducing the sweetness duration to values comparable to those of sucrose at 50 mg/L in the water system and 30 mg/L in the 10% vol edible alcohol system. Molecular docking suggested that puerarin may interact more favourably with the sweet taste receptor than GA, with a binding energy of −52.72 kJ/mol, and may weaken the predicted GA–receptor interaction, as reflected by the shift in GA binding energy from −41.00 to −21.30 kJ/mol. Overall, this study provides sensory parameters specific to different ethanol matrices for applying licorice extract in formulated spirits and offers a plausible receptor-level explanation, supported by molecular docking, for the ability of puerarin to mitigate GA-induced lingering sweetness, thereby supporting the development of formulated spirits with reduced sugar content.