College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, Jiangsu, China.
Department of Bioengineering, College of Life Science, Huaibei Normal University, Huaibei 235000, Anhui, China.
Food Funct. 2020 Jun 24;11(6):5133-5141. doi: 10.1039/d0fo00755b.
The applications of carvacrol are limited due to its poor stability and water solubility, and high volatility; however, ovalbumin can be used to encapsulate hydrophobic molecules, improve their aqueous solubility, and reduce their volatility. In this study, we fabricated ovalbumin-carvacrol nanoparticles (OCGns) under different pH (2, 5, 7, and 9) conditions using a gel embedding method and investigated their physicochemical and antibacterial properties. Rheological experiments revealed that the G' of ovalbumin gels (OGs) prepared under different pH conditions were OG-2 > OG-7 > OG-9 > OG-5. Carvacrol addition reduced the tight structure of ovalbumin and carvacrol under pH 5 and 7 conditions, with hardness first decreasing and then increasing, but increasing under pH 2 and 9 conditions. Fluorescence and infrared spectroscopy indicated complex formation, with carvacrol increasing the average diameter of nanoparticles prepared at pH 2, 5, 7, and 9. Encapsulation reached 89.34 and 91.86% at pH 2 and 9, respectively; however, inhibition experiments revealed that the minimum inhibitory concentration of OCGn-2 against Gram-positive Bacillus cereus and Salmonella (0.08 and 0.16 mg mL-1, respectively) was lower than that of OCGn-9 (both 0.28 mg mL-1). Moreover, OCGn-2 possessed a better dense gel structure and a higher stability, encapsulation rate, and antibacterial activity, suggesting that pH affects gel microstructure and thus the encapsulation efficiency and bacteriostatic properties of the prepared nanoparticles. These results contribute to our knowledge of the design and fabrication of polymeric nanoparticle delivery systems for bioactive compounds with beneficial properties.
香芹酚的应用受到其较差的稳定性、水溶性和高挥发性的限制；然而，卵清蛋白可用于包封疏水分子，提高其水溶解度并降低其挥发性。在本研究中，我们采用凝胶包埋法在不同 pH（2、5、7 和 9）条件下制备了卵清蛋白-香芹酚纳米颗粒（OCGns），并研究了它们的物理化学和抗菌性质。流变学实验表明，不同 pH 条件下制备的卵清蛋白凝胶（OGs）的 G'值为 OG-2>OG-7>OG-9>OG-5。香芹酚的加入降低了 pH 5 和 7 条件下卵清蛋白和香芹酚的紧密结构，硬度先降低后增加，但在 pH 2 和 9 条件下则增加。荧光和红外光谱表明形成了复合物，香芹酚增加了在 pH 2、5、7 和 9 条件下制备的纳米颗粒的平均直径。在 pH 2 和 9 时，包封率分别达到 89.34%和 91.86%；然而，抑菌实验表明，OCGn-2 对革兰氏阳性菌蜡样芽孢杆菌和沙门氏菌的最小抑菌浓度（0.08 和 0.16 mg mL-1）均低于 OCGn-9（均为 0.28 mg mL-1）。此外，OCGn-2 具有更好的致密凝胶结构和更高的稳定性、包封率和抗菌活性，表明 pH 影响凝胶的微观结构，从而影响所制备纳米颗粒的包封效率和抑菌性能。这些结果有助于我们了解设计和制造具有有益特性的生物活性化合物的聚合物纳米颗粒给药系统。
