Zili Zhou, Qing Jiang, Xiuying Liu, Zhihua Pang, Qian Shen, Lei Chen, Xinqi Liu, Wenping Ding, Lijie Zhu
These findings provide a theoretical basis of the mechanisms underlying bitterness perception by saponins.
Soyasaponins (Ssa) are strongly bitter, limiting food applications. In this study, acid hydrolysis generated secondary Ssa and aglycones, characterized by HPLC-TOF-MS. Bitterness decreases upon hydrolysis, with the sensory score increasing from 71.3 for native Ssa to 85.8 after complete hydrolysis. This reduction is attributed to the lower binding affinity of hydrolyzed Ssa for bitter taste receptors and mucin. Cellular assays demonstrated that Ssa Bb activated TAS2R14 (EC50 = 23.60 ± 16.53 μM) and TAS2R16 (EC50 = 451.8 ± 241.3 μM). Astringency changes correlated with interfacial and lubricating alterations. ITC indicates increased hydrophobicity of the complexes formed between salivary mucin and the samples, with the enthalpy decreased from 80.0 to 1.75 kcal/mol with hydrolysis temperature. Oral friction profiles show that Ssa and its hydrolysates reduce the friction coefficient of saliva. These findings provide a theoretical basis of the mechanisms underlying bitterness perception by saponins.