牛血清白蛋白与花青素纳米颗粒的特性及稳定性研究

目的：研究牛血清白蛋白（bovine serum albumin，BSA）与花青素相互作用形成的纳米颗粒的特性，及其对花青素的氧化稳定性的影响。方法：采用扫描透射电子显微镜和纳米粒度仪，研究BSA与笃斯越橘花青素形成纳米颗粒的表观形态及粒径大小，用盐析法测定BSA对花青素的结合量，并用自由基（DPPH自由基、ABTS＋·）清除方法和胃肠模拟体系分别研究BSA对花青素氧化稳定性的影响。结果：BSA-花青素在磷酸盐缓冲液（pH 7.4）中能通过自组装形成纳米颗粒，其纳米颗粒较BSA的粒径变小，由30～35 nm减小到15～20 nm。BSA对花青素的结合量是每摩尔BSA分子上结合的花青素为10 mol。BSA-花青素纳米颗粒较花青素的DPPH自由基、ABTS＋·清除能力明显增强。在胃模拟体系中，BSA与花青素结合对花青素稳定性没有显著性影响；在肠模拟体系中，BSA与花青素结合对花青素稳定性有显著性影响，未结合的花青素在6 h后含量降低70%左右，而有BSA结合的花青素含量几乎保持不变，表明BSA与花青素结合对花青素的氧化稳定性有明显的保护作用。

Characteristics of Bovine Serum Albumin-Anthocyanin Bioactive Nanoparticles

The nanoparticle formation between bovine serum albumin (BSA) and anthocyanin (ACN) was characterized
using scanning transmission electron microscope (STEM) and nanoparticles size analyzer. The anthocyanin-binding capacity
of BSA was studied by ammonium sulfate salting-out method. DPPH and ABTS radical scavenging capacities and release
characteristics in both simulated intestinal fluid (SIF) and simulated gastric fluid (SGF) systems were investigated for
oxidation stability of BSA-bound anthocyanin system. The results showed that both BSA and anthocyanin-bound BSA could
be self-assemble and form nanoparticles in phosphate buffer (pH 7.4), and the particle size (15–20 nm) of the anthocyaninbound
BSA was smaller than that of the BSA (30–35 nm). The molar binding ratio between BSA and antocyanin was 1:10.
The DPPH radical and ABTS＋· scavenging abilities of BSA-bound anthocyanin were significantly stronger than those
of unbound anthocyanin. There was no significant difference in stability between unbound anthocyanin and BSA-bound
anthocyanin in SGF system, while significant difference in SIF system was observed. The content of unbound anthocyanin
decreased by approximately 70% after 6 hours; however, no significant change was observed for BSA-bound anthocyanin.
BSA revealed remarkable stabilizing effect on anthocyanin oxidation.