da Costa Borges Marco Antonio, Sorigotti Amanda Rinaldi, Paschoalin Rafaella Takehara, Júnior José Alberto Paris, da Silva Lucas Henrique Domingos, Dias Diógenes Santos, Ribeiro Clóvis Augusto, de Araújo Elmo Silvano, Resende Flávia Aparecida, da Silva Barud Hernane
Laboratory of Biopolymers and Biomaterials (BIOPOLMAT), University of Araraquara (UNIARA), Araraquara, São Paulo 14801-340, Brazil.
Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCAR), São Carlos, São Paulo 13565-905, Brazil.
Polymers (Basel). 2023 Feb 11;15(4):914. doi: 10.3390/polym15040914.
Sterilization is a fundamental step to eliminate microorganisms prior to the application of products, especially in the food and medical industries. γ-irradiation is one of the most recommended and effective methods used for sterilization, but its effect on the properties and performance of bio-based polymers is negligible. This work is aimed at evaluating the influence of γ-radiation at doses of 5, 10, 15, 25, 30, and 40 kGy on the morphology, properties, and performance of bioplastic produced from onion bulb ( L.), using two hydrothermal synthesis procedures. These procedures differ in whether the product is washed or not after bioplastic synthesis, and are referred to as the unwashed hydrothermally treated pulp (HTP) and washed hydrothermally treated pulp (W-HTP). The morphological analysis indicated that the film surfaces became progressively rougher and more irregular for doses above 25 kGy, which increases their hydrophobicity, especially for the W-HTP samples. In addition, the FTIR and XRD results indicated that irradiation changed the structural and chemical groups of the samples. There was an increase in the crystallinity index and a predominance of the interaction of radiation with the hydroxyl groups-more susceptible to the oxidative effect-besides the cleavage of chemical bonds depending on the γ-radiation dose. The presence of soluble carbohydrates influenced the mechanical behavior of the samples, in which HTP is more ductile than W-HTP, but γ-radiation did not cause a change in mechanical properties proportionally to the dose. For W-HTP, films there was no mutagenicity or cytotoxicity-even after γ-irradiation at higher doses. In conclusion, the properties of onion-based films varied significantly with the γ-radiation dose. The films were also affected differently by radiation, depending on their chemical composition and the change induced by washing, which influences their use in food packaging or biomedical devices.
灭菌是在产品应用前消除微生物的基本步骤，尤其在食品和医疗行业。γ射线辐照是最推荐且有效的灭菌方法之一，但它对生物基聚合物的性能和表现的影响可忽略不计。本研究旨在评估5、10、15、25、30和40千戈瑞剂量的γ射线辐照对用两种水热合成方法由洋葱鳞茎（L.）制备的生物塑料的形态、性能和表现的影响。这两种方法的不同之处在于生物塑料合成后产品是否洗涤，分别称为未洗涤水热处理纸浆（HTP）和洗涤水热处理纸浆（W-HTP）。形态分析表明，对于剂量高于25千戈瑞的情况，薄膜表面逐渐变得更粗糙且更不规则，这增加了它们的疏水性，尤其是对于W-HTP样品。此外，傅里叶变换红外光谱（FTIR）和X射线衍射（XRD）结果表明，辐照改变了样品的结构和化学基团。结晶度指数增加，并且除了取决于γ射线辐照剂量的化学键断裂外，辐射与羟基的相互作用占主导地位——羟基更容易受到氧化作用的影响。可溶性碳水化合物的存在影响了样品的机械性能，其中HTP比W-HTP更具延展性，但γ射线辐照并未使机械性能与剂量成比例变化。对于W-HTP薄膜，即使在高剂量γ射线辐照后也没有致突变性或细胞毒性。总之，基于洋葱的薄膜的性能随γ射线辐照剂量有显著变化。这些薄膜受辐射的影响也因它们的化学组成以及洗涤引起的变化而不同，这影响了它们在食品包装或生物医学设备中的应用。
