College of Bioscience and Biotechnology, Fuzhou Univ., Fuzhou, 350108, China.
Guangdong Food and Drug Vocational College, Guangzhou, 510520, China.
J Food Sci. 2019 Jun;84(6):1411-1419. doi: 10.1111/1750-3841.14650. Epub 2019 May 27.
To improve the mechanical and antibacterial properties of chitosan (CS) films, a ternary blend edible film was prepared by incorporating CS, gelatin (GE), and natural cinnamon essential oil (CEo). Scanning electron microscopy (SEM), Atomic force microscopy (AFM), Fourier transform infrared spectroscopy, and X-ray diffraction were performed to evaluate the films. The mechanical properties, light transmission, thermal stability, hydrophilicity, and antibacterial activity of the films were also determined. The results confirmed all of the films exhibited excellent UV protection with low transparency at 600 nm. Compared with the CS films, the ternary composite film (CSGEo film, containing CS, GE, and CEo) had a higher elongation at break but a lower tensile strength. SEM images revealed that all films had smooth surfaces, although some obvious differences between CS and CSGEo films were observed by AFM. Additionally, the incorporation of GE and CEo to the films enhanced their thermal stability and contact angle, but decreased their crystallinity and wettability. The antimicrobial activity results showed that CSGEo films had excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus, for which the antibacterial rate exceeded 98%. The minimum inhibitory concentrations of the CSGEo solution against E. coli and S. aureus were both 52.06 µg/mL, and the minimal bactericidal concentrations were 104.12 and 52.06 µg/mL, respectively. These results suggest that CSGEo films possess good mechanical and antibacterial properties, and therefore, their application in the food packaging industry is promising. PRACTICAL APPLICATION: The main raw materials of the edible films developed in this study are aquatic by-products, so the films are edible and biodegradable. The addition of gelatin and CEo improved the UV barrier and thermal properties but decreased the crystallinity and hydrophilicity of the films, making them suitable for use as packaging materials. CEo-incorporated films exhibited excellent mechanical properties and antibacterial activity and can, therefore, be used in the food packaging industry.
为了提高壳聚糖（CS）薄膜的机械性能和抗菌性能，通过掺入 CS、明胶（GE）和天然肉桂精油（CEo）制备了三元共混可食用膜。通过扫描电子显微镜（SEM）、原子力显微镜（AFM）、傅里叶变换红外光谱和 X 射线衍射对薄膜进行了评估。还测定了薄膜的机械性能、透光率、热稳定性、亲水性和抗菌活性。结果证实所有薄膜在 600nm 时均具有出色的紫外线防护性能，透光率低。与 CS 薄膜相比，三元复合膜（CSGEo 薄膜，包含 CS、GE 和 CEo）具有更高的断裂伸长率，但拉伸强度较低。SEM 图像显示所有薄膜均具有光滑的表面，尽管 AFM 观察到 CS 和 CSGEo 薄膜之间存在一些明显差异。此外，将 GE 和 CEo 掺入到薄膜中提高了它们的热稳定性和接触角，但降低了它们的结晶度和润湿性。抗菌活性结果表明，CSGEo 薄膜对大肠杆菌和金黄色葡萄球菌具有出色的抗菌活性，抗菌率超过 98%。CSGEo 溶液对大肠杆菌和金黄色葡萄球菌的最低抑菌浓度均为 52.06µg/mL，最小杀菌浓度分别为 104.12 和 52.06µg/mL。这些结果表明 CSGEo 薄膜具有良好的机械性能和抗菌性能，因此在食品包装工业中有应用前景。实际应用：本研究开发的可食用膜的主要原料是水产副产品，因此该膜是可食用和可生物降解的。明胶和 CEo 的添加提高了薄膜的 UV 阻隔性能和热性能，但降低了薄膜的结晶度和亲水性，使其适合用作包装材料。含有 CEo 的薄膜具有出色的机械性能和抗菌活性，因此可用于食品包装工业。
