抗菌肽BCp12保鲜膜在乳扇贮藏保鲜中的应用

为延长乳扇的货架期，以酪蛋白、壳聚糖为原料包裹抗菌肽BCp12制备复合保鲜膜。采用单因素试验和正交试验确定最佳制备工艺，以膜的断裂伸长率、拉伸强度及抑菌活性为指标，结合扫描电子显微镜（scanning electron microscopy,SEM）、傅里叶变换红外光谱（Fourier transform infrared spectroscopy,FT-IR）及分子对接探究复合膜的形成机理，并将其应用于乳扇保鲜。结果表明，可食膜的最佳制备工艺为酪蛋白/壳聚糖质量比1∶1.5、BCp12质量浓度1 mg/mL、甘油质量分数1.5%、干燥温度55℃。SEM观察结果显示复合膜具有良好的相容性；FT-IR分析结果显示1 545.67 cm-1处为C—O伸缩振动吸收峰且结构稳定；分子对接结果表明BCp12与酪蛋白、壳聚糖之间主要通过残基Y4与—NH2活性位点产生氢键相互作用。与对照组相比，BCp12膜组乳扇的过氧化值变化较慢且经4℃贮藏后可使保质期延长60 d。综上，该膜能抑制腐败菌的生长，本实验可为BCp12/壳聚糖/酪蛋白复合膜的应用开发提供一定的技术参考。

Application of Edible Films Containing Antimicrobial Peptide BCp12 in Preservation of Milk Fan

In order to prolong the shelf life of milk fan, casein-chitosan edible films incorporated with antimicrobial peptide BCp12 were prepared. One-factor-at-a-time method combined with orthogonal array design was used to determine the optimum preparation process based on elongation at break and tensile strength. The antimicrobial activity of the composite film was evaluated, and its formation mechanism was explored by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and molecular docking. Finally, the composite film was applied to the preservation of milk fan. The results showed that the optimum preparation conditions were casein/chitosan mass ratio 1:1.5, BCp12 concentration 1 mg/mL, glycerin concentration 1.5% (m/m), and drying temperature 55 ℃. SEM showed good compatibility of the composite film and FT-IR analysis revealed that the film exhibited an absorption peak at 1 545.67 cm–1 attributed to the stretching vibration of C–O. Molecular docking showed that the hydrogen bond interaction between BCp12 and casein and chitosan occurred through the active sites of residues Y4 and –NH2. Compared with the control group, the change of peroxide value of milk fan treated with the antimicrobial film was slower and the shelf life was prolonged by 60 days during storage at 4 ℃, indicating the film could inhibit the growth of spoilage bacteria. The results of this study provide a technical reference for the development and application of chitosan-casein composite films incorporated with BCp12.