Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista, UNESP, Campus São José do Rio Preto, Departamento de Química e Ciências Ambientais, Laboratório de Biomateriais e Nanotecnologia, Cristóvão Colombo, 2265, São José do Rio Preto, Estado de São Paulo 15054-00, Brazil.
Empresa Brasileira de Pesquisa Agropecuária, EMBRAPA, Rua XV de Novembro, 1452, São Carlos, Estado de São Paulo 13560-970, Brazil.
Int J Biol Macromol. 2020 Dec 1;164:3411-3420. doi: 10.1016/j.ijbiomac.2020.08.145. Epub 2020 Aug 20.
Edible films and coatings can enhance the quality of food products, protecting them from biological deterioration, especially against fungal diseases and pathogenic microorganisms. In this study, films from chitosan, diethylaminoethyl-chitosan (DEAE-CH) and its hydrophobicized derivative DEAE-CH-DD were prepared by casting and their physicochemical and antimicrobial properties evaluated. The grafting with DEAE and dodecyl groups resulted in films with an elasticity modulus up to five times higher than commercial chitosan and increased water vapor permeability. Field emission gun - scanning electron microscopy and atomic force microscopy techniques showed films with smooth surfaces and the contact angle measurements revealed a correlation between the grafted group and hydrophilic/hydrophobic nature of the surface of the film. The amphiphilic derivatives exhibited better antimicrobial activity than unmodified chitosan against Penecillium expansum, Alternaria alternata and Alternaria solani. The amphiphilics DEAE-CH and DEAE-CH-DD showed no toxicity and delayed rotting and loss of water in strawberries and bananas, suggesting that this kind of film has great potential for increasing the shelf-life of different fruits.
可食用薄膜和涂层可以提高食品的质量，保护它们免受生物降解，特别是防止真菌疾病和病原微生物的侵害。在这项研究中，通过浇铸法制备了壳聚糖、二乙氨基乙基壳聚糖（DEAE-CH）及其疏水性衍生物 DEAE-CH-DD 的薄膜，并对其物理化学和抗菌性能进行了评估。用 DEAE 和十二烷基接枝导致薄膜的弹性模量比商业壳聚糖高五倍，并增加了水蒸气透过率。场发射枪扫描电子显微镜和原子力显微镜技术显示，薄膜具有光滑的表面，接触角测量表明接枝基团与薄膜表面的亲水性/疏水性之间存在相关性。与未改性壳聚糖相比，两亲性衍生物对扩展青霉、链格孢属和茄病镰刀菌表现出更好的抗菌活性。两亲性的 DEAE-CH 和 DEAE-CH-DD 没有显示出毒性，并且可以延缓草莓和香蕉的腐烂和水分流失，这表明这种薄膜在延长不同水果的保质期方面有很大的潜力。
