Abstract Quercetin is an antioxidant flavonol very sensible to light and oxidants that can benefit from stabilisation by encapsulation into cyclodextrins. In this work we study the solid inclusion compounds of quercetin with β- and γ-cyclodextrins (β-CD and γ-CD) obtained by freeze-drying. Combined results from microanalysis, FT-IR, powder X-ray diffraction, 13 C{ 1 H} CP/MAS NMR spectroscopy and thermogravimetry demonstrating that γ-CD, having a larger cavity, is the most adequate host to form a stable inclusion complex with quercetin. The anti-peroxidation capacity of the compounds was determined and followed the order β-CD·quercetin ≫ quercetin > γ-CD·quercetin. Both γ-CD·quercetin and β-CD·quercetin are able to inhibit DPPH radicals at a rate three times faster than pure quercetin, but their EC 50 is higher (50 μM vs 17 μM for quercetin). The practical applicability of the two CD·quercetin adducts as nutraceutical additives in fresh cheese was established. Fortified fresh cheese had a firmer texture and yellowish colour, but no significant changes in the overall sensorial qualities were found by a panel of non-trained tasters when compared with the control (non-treated fresh cheese).

中文翻译：

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固体包合物γ-环糊精·槲皮素与β-环糊精·槲皮素的理化性质、抗氧化作用及在新鲜奶酪中的实际应用

摘要 槲皮素是一种抗氧化剂黄酮醇，对光和氧化剂非常敏感，可通过包封到环糊精中而受益于稳定性。在这项工作中，我们研究了通过冷冻干燥获得的槲皮素与 β- 和 γ- 环糊精（β-CD 和 γ-CD）的固体包合物。微量分析、FT-IR、粉末 X 射线衍射、 13 C{ 1 H} CP/MAS NMR 光谱和热重分析的综合结果表明，具有较大腔的 γ-CD 是最适合形成稳定包合物的宿主与槲皮素。测定化合物的抗过氧化能力并遵循β-CD·槲皮素≫槲皮素>γ-CD·槲皮素的顺序。γ-CD·槲皮素和β-CD·槲皮素均能以比纯槲皮素快三倍的速率抑制DPPH自由基，但它们的EC 50 更高（50 μM vs 17 μM槲皮素）。确定了两种CD·槲皮素加合物作为新鲜干酪营养添加剂的实际适用性。强化新鲜奶酪质地更硬，颜色偏黄，但与对照（未经处理的新鲜奶酪）相比，未经培训的品尝者小组未发现整体感官品质发生显着变化。