卵清蛋白包封山奈酚和单宁酸纳米颗粒的理化性质和抗氧化活性

Physicochemical Properties and Antioxidant Activity of Ovalbumin-encapsulated Nanoparticles of Kaempferol and Tannic Acid

摘要:

为探究卵清蛋白（Ovalbumin, OVA）包封对多酚类物质的稳定性和抗氧化活性的影响，该文以OVA作递送载体，疏水性多酚山奈酚（Kaempferol, KAE）与亲水性多酚单宁酸（Tannic acid, TA）为活性包埋成分，制备OVA-TA、OVA-KAE和OVA-TA-KAE复合纳米颗粒，对其理化性质和抗氧化活性进行表征。结果表明，OVA对KAE和TA具有较好的包封效果；KAE提高了纳米颗粒的热稳定性；TA提高了其结构稳定性和抗氧化活性，使OVA更好地包埋两种多酚。粒径和zeta电位、内源性荧光分析、傅里叶变换红外光谱、X射线衍射和扫描电镜结果表明，KAE/TA被很好的包封于OVA中，三种纳米颗粒结构稳定、均匀分散；OVA与TA结合较好，蛋白质结构稳定性最高，且蛋白质保持了稳定的三维结构。差示扫描量热法分析表明，KAE增强了纳米颗粒空间结构的热稳定性。总酚含量和抗氧化活性分析表明，OVA包封抑制了多酚降解，其中OVA-TA-KAE的总酚含量和DPPH清除能力分别为141.33 mg/g和4909.36 μmol Trolox/g。该研究为OVA纳米颗粒负载KAE/TA提供了新见解，评估了OVA封装保护KAE和TA抗氧化活性的有效性和可行性。

Abstract:

To investigate the effect of ovalbumin (OVA) encapsulation on the stability and antioxidant activity of polyphenolic compounds, OVA was used as a delivery carrier, with the hydrophobic polyphenol kaempferol (KAE) and the hydrophilic polyphenol tannic acid (TA) as the active compounds. OVA-TA, OVA-KAE, and OVA-TA-KAE composite nanoparticles were prepared, and their physicochemical properties and antioxidant activities were characterized. The results indicated that OVA exhibited good encapsulation efficiency for both KAE and TA. KAE enhanced the thermal stability of the nanoparticles, while TA improved their structural stability and antioxidant activity, leading to better encapsulation of the two polyphenols by OVA. Particle size, zeta potential, intrinsic fluorescence analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) results showed that KAE/TA were effectively encapsulated within OVA, and the three nanoparticles were structurally stable and uniformly dispersed. OVA formed a good bond with TA, resulting in the highest protein structural stability, with the protein maintaining a stable three-dimensional structure. Differential scanning calorimetry (DSC) analysis indicated that KAE enhanced the thermal stability of the nanoparticle's spatial structure. The total phenol content, DPPH radical scavenging activity, ABTS+ radical scavenging activity, and FRAP antioxidant activity, measured by the Folin-Ciocalteu method, revealed that OVA encapsulation inhibited the degradation of polyphenols. Among them, OVA-TA-KAE exhibited total phenol content and DPPH scavenging activity of 141.33 mg/g and 4909.36 μmol Trolox/g, respectively. This study provides new insights into the loading of KAE/TA in OVA nanoparticles and evaluates the effectiveness and feasibility of OVA encapsulation in protecting the antioxidant activity of KAE and TA.