Mao Long, Dong Zhiye, Dong Fang, Dai Xianglong, Cao Zhiming
Fujian Provincial Key Laboratory of Functional Materials and Applications, Xiamen University of Technology, Xiamen 361024, PR China.
Fujian Provincial Key Laboratory of Functional Materials and Applications, Xiamen University of Technology, Xiamen 361024, PR China.
Int J Biol Macromol. 2025 Mar;296:139738. doi: 10.1016/j.ijbiomac.2025.139738. Epub 2025 Jan 10.
Natural polymer based food packaging has attracted more and more attention, but the lack of active functions of natural polymer hinders its application in the field of active packaging. In this study, chlorogenic acid carbon dots (CGA-CDs) was synthesized mildly using natural plant polyphenol CGA as carbon source, and CGA functionalized layered clays (LDHs@CGA) was introduced as reinforcing agent. Alg active films were fabricated by solution casting method using natural polysaccharide-alginate (Alg), CGA-CDs and LDHs@CGA. The results showed that the average particle size of the synthesized CGA-CDs was ∼2.0 nm, with obvious graphitized structure inside and active groups (-OH and -NH, etc.) outside, showing obvious UV absorption and antibacterial activity. With the addition of CGA-CDs, UV barrier, antibacterial, thermal stability, hydrophobicity and flexibility of Alg active films were significantly improved. When the amount of CGA-CDs reached 2 %, UV transmission (280 nm) and of Alg active films was only 2.66 %, which was reduced by 88.1 % compared with pure Alg film. The highest antibacterial rate against Escherichia coli and Staphylococcus aureus reached 86.0 % and 91.6 %, respectively. Freshness preservation experiment of fresh-cut apples indicated that Alg active coating incorporating CGA-CDs maintained the lowest browning index and mildew. These results indicate that the excellent active functions of CGA-CDs can promote the application of Alg matrix in the field of natural polymer active packaging.
基于天然聚合物的食品包装越来越受到关注，但天然聚合物缺乏活性功能阻碍了其在活性包装领域的应用。在本研究中，以天然植物多酚绿原酸（CGA）为碳源温和合成了绿原酸碳点（CGA-CDs），并引入CGA功能化层状粘土（LDHs@CGA）作为增强剂。采用天然多糖海藻酸钠（Alg）、CGA-CDs和LDHs@CGA通过溶液浇铸法制备了Alg活性薄膜。结果表明，合成的CGA-CDs平均粒径约为2.0 nm，内部具有明显的石墨化结构，外部有活性基团（-OH和-NH等），表现出明显的紫外吸收和抗菌活性。随着CGA-CDs的加入，Alg活性薄膜的紫外线阻隔性、抗菌性、热稳定性、疏水性和柔韧性均得到显著提高。当CGA-CDs的用量达到2%时，Alg活性薄膜在280 nm处的紫外线透过率仅为2.66%，与纯Alg薄膜相比降低了88.1%。对大肠杆菌和金黄色葡萄球菌的最高抗菌率分别达到86.0%和91.6%。鲜切苹果的保鲜实验表明，含有CGA-CDs的Alg活性涂层保持了最低的褐变指数和霉菌数。这些结果表明，CGA-CDs优异的活性功能可以促进Alg基体在天然聚合物活性包装领域的应用。
