可食性抗菌肽-明胶复合膜的制备及性能表征

Preparation and Characterization of Edible Antibacterial Peptide-gelatin Composite Films

摘要:

为了研究新型的可食性抗菌包装材料，以明胶、甘油、不同浓度的抗菌肽为抗菌剂制备了抗菌肽-明胶复合膜。以光学性能等指标以及傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）和差示扫描量热仪（DSC）对复合膜的性能进行表征。结果表明：添加了抗菌肽的明胶复合膜在250~300 nm波长范围内吸收显著提高，抗菌肽的添加使膜的颜色偏黄，机械性能得到一定的改善，如50 mg/mL的抗菌肽添加量使水蒸气透过率具有一定程度降低（与纯明胶相比降低了17.30%），膜的抗拉强度（TS）和断裂伸长率（EAB）与纯明胶膜相比，分别增加了11.40%和42.90%）。当抗菌肽的添加量为50 mg/mL时，薄膜抗菌能力最为显著（对大肠杆菌和金黄色葡萄球菌的抑菌圈直径分别为14.60 mm和12.30 mm）。FT-IR和SEM显示复合膜有良好的相容性。DSC数据显示抗菌肽对复合膜的热稳定性有一定程度的降低作用。

Abstract:

In order to study novel edible antibacterial packaging materials, antibacterial peptide-gelatin composite films were prepared using gelatin, glycerol, and different concentrations of antibacterial peptides as antibacterial agents. The properties of the composite films were characterized based on optical properties and by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and differential scanning calorimeter (DSC). The results showed that the addition of the antibacterial peptide to the gelatin-based composite films increased the absorption in the wavelength range of 250~300 nm, made the film color slightly turn yellow, and improved film’s mechanical properties. Adding 50 mg/mL of antibacterial peptide reduced the water vapor permeability to a certain extent (17.30% reduction compared to the film made with gelatin alone), increased film tensile strength (TS) and elongation at break (EAB) by 11.40% and 42.90%, respectively (compared to the film made with gelatin alone), and enabled the highest film antibacterial activity (the diameters of the inhibition zones against Escherichia coli and Staphylococcus aureus were 14.60 mm and 12.30 mm, respectively). The FT-IR and SEM examinations revealed the good compatibility of the composite films. DSC results showed that antimicrobial peptides might reduce the thermal stability of the composite films to some extent.