ABSTRACT

A novel and smart hydrogel was synthesized from N, N dimethyl acrylamide (DMAAm), gelatin, and citric acid (CA) red apple peel extract (RApE) to be utilized as a multi-functional food packaging material. The p(Gelatin-co-DMAAm)/CA-RApE was prepared through a redox polymerization technique in film form in petri dishes. Mechanical and water resistance of the p(Gelatin-co-DMAAm)/CA-RApE was improved by the addition of citric acid and N, N, methylenebisacrylamide (MBA) as cross linker. The characterization of p(Gelatin-co-DMAAm)/CA-RApE was carried out by Fourier transform infrared spectroscopy (FT-IR), thermo gravimetric analyzer (TGA), scanning electron microscopy (SEM), and dynamic and mechanical analyzer (DMA). FT-IR revealed the existence of bonding interactions between the functional group of RApE and gelatin, carbonyl groups of DMAAm, and carboxylic acid groups of CA. TGA results found that p(Gelatin-co-DMAAm)/CA-RApE was stable up to 565°C. It was observed that RApE improved thermal stability and decreased the elasticity of the p(Gelatin-co-DMAAm)/CA-RApE. When tested against Escherichia coli, Bacillus subtilis and Staphylococcus aureus, p(Gelatin-co-DMAAm)/CA-RApE was observed to have antimicrobial activity. Total antioxidant and anthocyanin effect of p(Gelatin-co-DMAAm)/CA-RApE was analyzed. Additionally, to monitor the color changes of p(Gelatin-co-DMAAm)/CA-RApE, it was studied at different pH values. Furthermore, p(Gelatin-co-DMAAm)/CA-RApE was applied to real samples such as whole pasteurized milk and cheese. It was found to have a good color indicator and antimicrobial activity for pasteurized whole milk and cheese. It was concluded that p(Gelatin-co-DMAAm)/CA-RApE is a very good candidate to be used in food packaging and biomedical materials, along with other potential applications.

摘要

由N，N二甲基丙烯酰胺（DMAAm），明胶和柠檬酸（CA）红苹果皮提取物（RApE）合成了一种新颖而智能的水凝胶，可用作多功能食品包装材料。p（明胶-co-DMAAm）/ CA-RApE通过氧化还原聚合技术在皮氏培养皿中以膜形式制备。通过添加柠檬酸和N，N，亚甲基双丙烯酰胺（MBA）作为交联剂，可以改善p（明胶-co-DMAAm）/ CA-RApE的机械性能和耐水性。通过傅立叶变换红外光谱（FT-IR），热重分析仪（TGA），扫描电子显微镜（SEM）以及动态和机械分析仪（DMA）对p（明胶-co-DMAAm）/ CA-RApE进行表征）。FT-IR揭示了RApE的功能基团与明胶，DMAAm的羰基，和CA的羧酸基团。TGA结果发现，p（明胶-co-DMAAm）/ CA-RApE在565°C时稳定。观察到，RApE提高了热稳定性并降低了p（明胶-co-DMAAm）/ CA-RApE的弹性。当针对大肠杆菌，枯草芽孢杆菌和金黄色葡萄球菌进行测试时，观察到p（明胶-co-DMAAm）/ CA-RApE具有抗菌活性。分析了p（明胶-co-DMAAm）/ CA-RApE的总抗氧化剂和花青素作用。另外，为了监测p（明胶-co-DMAAm）/ CA-RApE的颜色变化，在不同的pH值下进行了研究。此外，将p（明胶-co-DMAAm）/ CA-RApE应用于真实样品，例如全巴氏灭菌的牛奶和奶酪。已发现它对巴氏消毒的全脂牛奶和奶酪具有良好的颜色指示剂和抗菌活性。