Wan Jin-Yan, Long Yu, Zhang Yu-Lu, Xiang Yan, Liu Song-Yu, Li Nan, Zhang Ding-Kun
College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
Chin Herb Med. 2021 May 28;13(3):421-429. doi: 10.1016/j.chmed.2021.05.003. eCollection 2021 Jul.
Tea polyphenols are natural extracts used widely throughout the world. However, the severe astringency of tea polyphenols has reduced patient compliance. Based on the analysis of the formation mechanism of astringency, this paper hopes to propose a new method to control the astringency of tea polyphenols and improve patient compliance without changing its effect.
Artificial saliva was used to prepare the tea polyphenols solution with different pH, using β-casein to imitate salivary protein, and preparing 1.2 mg/mL β-casein solution. A fluorescence quenching test was used to study the interaction between tea polyphenols and β-casein, combined with the stability test results of the compound, we can choose the pH with weak binding but good stability as the best pH for masking astringency. The taste-masking tablets were prepared under the best pH conditions, and the Xinnaojian Original Tablets were prepared according to the conventional preparation method. The disintegration time limit and solubility were tested respectively. The astringency of Xinnaojian original tablets and taste-masking tablets was evaluated by visual analogue scale (VAS).
The result of the fluorescence quenching test prompted that the combination force was the weakest when the pH was 4.9. Further synchronous fluorescence analysis showed that an increase in pH resulted in a decrease of the binding sites between tea polyphenols and β-casein, and this decrease was closely related to changes in tryptophan residues in β-casein. Both original and taste-masking Xinnaojian Tablets were prepared. Volunteers' VAS scores illustrated that the astringency improved significantly with the masking tablets ( < 0.05).
This pH-adjusting masking treatment had little effect on the recovery of polyphenols from the tablets or the dissolution of the tablets. This study provides a novel and feasible astringency masking technology for tea polyphenols and its preparation.
茶多酚是在全球广泛使用的天然提取物。然而，茶多酚的严重涩味降低了患者的依从性。基于对涩味形成机制的分析，本文希望提出一种控制茶多酚涩味的新方法，在不改变其效果的情况下提高患者依从性。
用人工唾液制备不同pH值的茶多酚溶液，用β-酪蛋白模拟唾液蛋白，制备1.2mg/mL的β-酪蛋白溶液。采用荧光猝灭试验研究茶多酚与β-酪蛋白之间的相互作用，结合复合物的稳定性试验结果，选择结合较弱但稳定性良好的pH值作为掩盖涩味的最佳pH值。在最佳pH条件下制备掩味片，并按照常规制备方法制备心脑健原片。分别测试崩解时限和溶解度。用心脑健原片和掩味片的视觉模拟评分法（VAS）评价涩味。
荧光猝灭试验结果表明，pH为4.9时结合力最弱。进一步的同步荧光分析表明，pH升高导致茶多酚与β-酪蛋白之间的结合位点减少，这种减少与β-酪蛋白中色氨酸残基的变化密切相关。制备了心脑健原片和掩味片。志愿者的VAS评分表明，掩味片的涩味明显改善（<0.05）。
这种pH调节掩味处理对片剂中多酚的回收率或片剂的溶出度影响很小。本研究为茶多酚及其制剂提供了一种新颖可行的涩味掩盖技术。
