多糖基广谱抗菌薄膜的制备及性能研究

Preparation and properties of polysaccharide-based broad-spectrum antibacterial films

目的:开发具有优良抗菌、理化性能的多糖基复合抗菌薄膜,提高食品的货架期。方法:以卡拉胶、琼脂、魔芋胶及果胶为成膜基材,纳他霉素、纳米MgO为抗菌剂,考察抗菌剂对薄膜物理、力学、抗菌等性能及葡萄保鲜的影响。结果:加入抗菌剂后,薄膜厚度、拉伸强度、雾度增大,透气性升高,断裂伸长率降低;水溶性、溶胀度、透湿性下降;透光率及光泽度降低,颜色趋向黄绿色;与薄膜填料间相容良好;能有效抑制毛霉、根霉、黑曲霉、金黄色葡萄球菌、大肠杆菌、志贺氏菌和沙门氏菌的生长繁殖,其中各指标良好的卡拉胶/纳他霉素/纳米MgO复合薄膜(CNM)、琼脂/纳他霉素/纳米MgO复合薄膜(ANM)均能延缓葡萄的失水速率、改善硬度下降和可溶性固形物含量减少的状况,保证葡萄的外观及营养品质。结论:ANM膜和CNM膜适用于延长食品保质期的抗菌包装材料,可开发成具备抗菌保鲜功能的果蔬保鲜膜。

Objective:This study aimed to develop polysaccharide-based composite antibacterial films with excellent antibacterial and physicochemical properties to effectively improve the shelf life of food.Methods:Carrageenan,agar,konjac gum and pectin were used as film-forming substrates and natamycin and nano-MgO were used as antibacterialagents to investigate the effects of adding antimicrobial agents on the physical,mechanical and antibacterial properties of the films and the preservation of grapes.Results:After the addition of antibacterial agents,the film thickness,tensile strength and haze increased,air permeability increased and elongation at break decreased,water solubility,swelling and moisture permeability decreased,light transmission and gloss decreased and the color tended to yellow-green,good compatibility with the film filler.It can effectively inhibit the growth and reproduction of Trichoderma,Rhizopus,Aspergillus,Staphylococcus aureus,Escherichia coli,Shigella and Salmonella,among which carrageenan/natamycin/nano-MgO composite membrane(CNM)and agar/natamycin/nano-MgO composite membrane(ANM)with good indicators can delay the water loss rate of grapes,improve the decline in hardness and the reduction of soluble solids content,and ensure the appearance and nutritional quality of grapes.Conclusion:ANM and CNM films are suitable for use as antibacterial packaging materials to extend the shelf life of food products,and are expected to be developed into fruit and vegetable preservation films with antibacterial preservation functions.