Polyolefins Journal, Vol. 12, No. 1 (2025) IPPI DOI: 10.22063/POJ.2025.35579.1336 Effect of lysozyme and glucose oxidase on the physical-mechanical and barrier properties of linear low-density polyethylene Ali Yakoub Alkhair * , Emiru Yidnekachew Melesse, Irina Anatol'evna Kirsh, Yulia Aleksandrovna Filinskaya, Izabella Sergeevna Tveritnikova, Oleg Igorevich Mihryachev Department of Industrial Design Packaging Technologies and Expertise, Federal State Budgetary Educational Institution of Higher Education Russian Biotechnology University, Moscow, Russia Federation Received: 21 October 2024, Accepted: 26 January 2025 ABSTRACT B iocomposites were synthesized from linear low-density polyethylene (LLDPE) with lysozyme, mixed lysosome, and glucose oxidase enzyme via a melt extrusion system. The aim of this work was to evaluate and characterize the effect of lysosome, mixed lysosome and glucose oxidase enzymes on the mechanical, water vapor transfer rate, and structural appearance of LLDPE biocomposite films. In this regard, 50 g of LLDPE pellets were applied along with 1%, 5%, and 10% (w/w) of lysozyme alone and lysosome mixed with glucose oxidase. Pure LLDPE was used as a control. Overall, the biocomposite with 5 and 10% (w/w) of mixed lysosome and glucose oxidase enzymes did not perform well and was not even sufficient for characterization. The surface structure of the biocomposites was examined through a digital microscope to identify the dispersion of enzymes within the LLDPE matrix, and it was found that at higher concentrations (10% w/w) a dense and large surface was formed. However, good dispersion and reinforcing ability of enzymes in the LLDPE matrix were observed at low concentrations of lysosomal enzymes (1 and 5% w/w). It was found that the mechanical strength and elongation-at-break of the biocomposite films increased at low enzyme concentrations (1 and 5 wt.%), but decreased with increasing enzyme concentration. On average, vapor permeability increased with increasing enzyme concentration. Besides, the Fourier transform infrared spectroscopy (FTIR) was used to determine the structural configuration of the enzymes in the LDPE matrix. Single sharp stretching breaks at 570 cm -1 (1, 5 and 10 wt.%) was corresponded to the existence of enzyme bands. Overall, the addition of lysosomes and glucose oxidase at low concentrations has great potential in the development of biocomposites compared to traditional plastic composites. Polyolefins J (2025) 12: 53-60 Keywords: Linear low-density polyethylene; lysosome and glucose oxidase enzymes; water vapor permeability; mechanical and barrier properties; FTIR spectroscopy. * Corresponding Authors - E-mail: alkhaira@mgupp.ru ORIGINAL PAPER INTRODUCTION Packaging in the food industry is essential to maintaining the quality of products and ensuring their safety for consumers and helps control the shelf life of products. Packaging can solve many of the problems associated with currently used food preservation methods, and this has been proven by research in the last decade of this century [1,2]. Extending the shelf life of food products using active packaging does not require exposing food products to high temperatures, which leads to the destruction of heat-sensitive nutrients as traditional drying and pasteurization [3]. Creating active packaging also does not require a huge amount of energy or high costs, as is the case with the sublimation method [4]. Consumer safety will be guaranteed when using safe polymeric materials and natural antimicrobial additives in appropriate concentrations in the food industry. This cannot be guaranteed if traditional preservatives added directly to food are used [5]. There is also no need to release air from the packaging and destroy the structure of the food product, as is the case with vacuum packaging.