Sakai Takahiro, Akagi Yumiko, Suzuki Hisashi, Irie Mitsuki, Nakamura Tetsuya, Sato Hisako, Kawamura Izuru
R&D Center, T. Hasegawa Co., Ltd., 29-7 Kariyado, Nakahara, Kawasaki, Kanagawa, 211-0022, Japan.
Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama, Kanagawa, 240-8501, Japan.
Anal Sci. 2020 Nov 10;36(11):1337-1343. doi: 10.2116/analsci.20P120. Epub 2020 Jun 19.
Hydrophobic and volatile flavor molecules can be encapsulated inside cyclodextrins (CyDs). Inclusion complexes are frequently used in solid or dispersed states in preserved food and cosmetics. In this study, the solid-state structures of spray-dried inclusion complexes of l-menthol in α-CyD and β-CyD were analyzed using C solid-state NMR and vibrational circular dichroism (VCD). The NMR signals of l-menthol and CyDs were identified in the physical mixture and the l-menthol inclusion complex of α- and β-CyD. The NMR signal of the isopropyl-methyl group of menthol in the α-CyD inclusion complex exhibited a large low-field shift, which suggested a steric hindrance between menthol and α-CyD. VCD exhibited specific changes in the intensity of bands corresponding to C-C vibrations in α-CyD and O-C stretching vibrations in l-menthol. Our results indicated that l-menthol specifically fitted the narrow space within α-CyD. The combined solid-state NMR and VCD analysis provided structural insights into the flavor inclusion complex in the solid-state.
疏水性和挥发性风味分子可以被包封在环糊精（CyDs）内部。包合物常用于保藏食品和化妆品的固态或分散态中。在本研究中，使用碳固态核磁共振（C 固体核磁共振）和振动圆二色性（VCD）分析了喷雾干燥的 l-薄荷醇与α-环糊精和β-环糊精包合物的固态结构。在物理混合物以及α-环糊精和β-环糊精的 l-薄荷醇包合物中鉴定出了 l-薄荷醇和环糊精的核磁共振信号。α-环糊精包合物中薄荷醇异丙基甲基的核磁共振信号表现出较大的低场位移，这表明薄荷醇与α-环糊精之间存在空间位阻。VCD 在对应于α-环糊精中 C-C 振动和 l-薄荷醇中 O-C 伸缩振动的谱带强度上表现出特定变化。我们的结果表明，l-薄荷醇能特异性地适配α-环糊精内的狭窄空间。固态核磁共振和 VCD 的联合分析为固态风味包合物提供了结构上的见解。
