Dong Fang, Dong Zhiye, Mao Long, Yao Jin, Wang Chengyu
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. 2024 Oct;277(Pt 2):134095. doi: 10.1016/j.ijbiomac.2024.134095. Epub 2024 Jul 24.
In order to improve the functionality of natural gelatin films for active food packaging applications, a combined strategy of crosslinking via Maillard reaction and blending enhancement incorporated with poly(vinyl alcohol) (PVA) was explored. In this study, when the mass ratio of gelatin to glucose was 10:1, Maillard reaction of crosslinked gelatin films was the highest, UV absorption and browning index reached the maximum. Infrared analysis showed that PVA could form strong interfacial interactions with gelatin matrix. The presence of PVA could significantly improve the toughness, water absorption, transparency, and oxygen barrier properties of crosslinked gelatin films. When the amount of PVA reached 5 %, elongation at break and oxygen barrier properties of crosslinked gelatin films were improved by 76.7 % and 47.9 % compared with pure crosslinked gelatin film. Even when the amount of PVA reached 10 %, UV absorption (at 315 nm) of crosslinked gelatin films still exceeded 98.7 %. The addition of PVA could accelerate the dissolution and swelling of crosslinked gelatin films, promoting the migration and release of active substances (Maillard reaction products (MRPs)). The two antioxidant activities tests (DPPH and ABTS method) achieved the highest radical scavenging rates of 71.6 % and 91.2 %, respectively, with corresponding PVA addition of 5 % and 7.5 %. After continuing to add PVA, antioxidant activities began to significantly decrease, which was directly related to the decrease in the generation of MRPs. Therefore, crosslinked gelatin films reinforced with appropriate amount of PVA can be considerable potential as active films for renewable food packaging applications.
为了改善天然明胶薄膜在活性食品包装应用中的功能，探索了通过美拉德反应交联和与聚乙烯醇（PVA）共混增强的组合策略。在本研究中，当明胶与葡萄糖的质量比为10:1时，交联明胶薄膜的美拉德反应最高，紫外线吸收和褐变指数达到最大值。红外分析表明，PVA能与明胶基质形成强界面相互作用。PVA的存在能显著改善交联明胶薄膜的韧性、吸水性、透明度和氧气阻隔性能。当PVA用量达到5%时，交联明胶薄膜的断裂伸长率和氧气阻隔性能相比纯交联明胶薄膜分别提高了76.7%和47.9%。即使PVA用量达到10%，交联明胶薄膜在315nm处的紫外线吸收仍超过98.7%。PVA的添加能加速交联明胶薄膜的溶解和溶胀，促进活性物质（美拉德反应产物（MRPs））的迁移和释放。两种抗氧化活性测试（DPPH和ABTS法）分别在PVA添加量为5%和7.5%时达到了最高的自由基清除率，分别为71.6%和91.2%。继续添加PVA后，抗氧化活性开始显著下降，这与MRPs生成量的减少直接相关。因此，用适量PVA增强的交联明胶薄膜作为可再生食品包装应用的活性薄膜具有相当大的潜力。
