Tohamy Hebat-Allah S
Cellulose and Paper Department, National Research Centre, 33 El Bohouth Str., P.O. 12622, Dokki, Giza, Egypt.
Sci Rep. 2025 Jul 26;15(1):27311. doi: 10.1038/s41598-025-10294-6.
This study presents a new type of intelligent food packaging material. The film is created using hydroxyethyl cellulose (HEC) and carbon dots that have been modified with sulfur and nitrogen (S,N-CQDs). These S,N-CQDs are produced from discarded onion peels waste, making the packaging eco-friendly and versatile for food preservation with naked eye response.. The S,N-CQDs within the HEC film (HEC-S,N-CQDs) exhibit remarkable fluorescent change when contact with Salmonella. When applied to chicken meat, the film effectively monitors spoilage by changing color from red to light red. This color change is attributed to the film's pH sensitivity and its interaction with the increasing pH associated with meat deterioration. The color change which visualized by the naked-eye was an indication of the chicken meat spoilage. These make the film capable of visually detecting changes in food quality, such as spoilage, and inhibiting the growth of foodborne pathogens like Salmonella. Additionally, the antimicrobial properties of S,N-CQDs contribute to extending the shelf life of the packaged meat by 12 days which is more longer than the film without S,N-CQDs (3 days). DFT calculations and decreased the energy gap (0.02664 eV) prove the strong chemical reaction between HEC and S,N-CQDs within the film. The low bond length between the ligand and Salmonella (2.43 A°) compared to the HEC film without S,N-CQDs (2.54 A°) prove the high efficiency of antimicrobial activity for the film which containing S,N-CQDs.
本研究提出了一种新型智能食品包装材料。该薄膜是用羟乙基纤维素(HEC)和经硫和氮修饰的碳点(S,N-CQDs)制成的。这些S,N-CQDs由废弃洋葱皮废料制成,使包装具有环保性且在肉眼可见的反应下对食品保鲜具有多功能性。HEC薄膜(HEC-S,N-CQDs)中的S,N-CQDs与沙门氏菌接触时会表现出显著的荧光变化。应用于鸡肉时,该薄膜通过从红色变为浅红色来有效监测变质情况。这种颜色变化归因于薄膜的pH敏感性及其与肉类变质相关的pH值升高之间的相互作用。肉眼可见的颜色变化表明鸡肉已经变质。这些特性使该薄膜能够直观地检测食品质量的变化,如变质,并抑制沙门氏菌等食源性病原体的生长。此外,S,N-CQDs的抗菌性能有助于将包装肉类的保质期延长12天,这比不含S,N-CQDs的薄膜(3天)长得多。密度泛函理论计算和减小的能隙(0.02664 eV)证明了薄膜中HEC与S,N-CQDs之间存在强烈的化学反应。与不含S,N-CQDs的HEC薄膜(2.54 Å)相比,配体与沙门氏菌之间较低的键长(2.43 Å)证明了含S,N-CQDs的薄膜具有高效的抗菌活性。