Emulsions are dispersed systems composed of multiple immiscible liquids with various applications in the food industry (Ramsden, 1903). Conventional emulsions are stabilized using surfactants, whereas Pickering emulsions are stabilized by solid particles such as proteins (Lim & Salentinig, 2021), starches (F. Zhu, 2019), chitosan (Shen et al., 2014), cellulose (Tang et al., 2018) and polysaccharide/protein complexes (Yin, Wang, & Zeng, 2023). Pickering emulsions exhibit superior stability characteristics including anti-coalescence and anti-Ostwald ripening properties (McClements & Gumus, 2016). Bacterial cellulose (BC) has been considered as a potential material for numerous biomedical applications due to its non-toxicity, high purity, and biocompatibility (W. Liu et al., 2020; Sommer & Staroszczyk, 2023). The mechanism by which BC stabilizes Pickering emulsions primarily includes two aspects. Firstly, irreversible adsorption of low-length bacterial cellulose nanocrystals (BCNC) and bacterial cellulose nanofibers (BCNF) at the oil-water interface stabilization emulsions (Lu, Li, Ge, Xie, & Wu, 2021), known as steric effect (Chevalier & Bolzinger, 2013). Secondly, large-aspect-ratio BCNF exhibits limited adsorption capability at interfaces but demonstrates a tendency for entanglement and extended-chain conformation in water phase. At high polymer concentrations, the polymer could slow the creaming instability (Wang et al., 2023; Zhang et al., 2022).

Many studies have reported that BC degraded by various methods shows excellent emulsifying properties. For instance, sulfuric acid hydrolysis (Sommer and Staroszczyk, 2023), hydrochloric acid hydrolysis (Gao et al., 2023). High-pressure homogenization (Li et al., 2021; Li et al., 2023) and TEMPO-mediated oxidation (Zhang et al., 2020) have been investigated. However, traditional BC degradation techniques will consume abundant energy and result in resource wastage. In light of environmental concerns, there is a growing interest in exploring green innovative approaches as an alternative to conventional processes. Electron beam irradiation (EBI) emerges as a promising alternative to conventional processes for cellulose degradation, offering numerous advantages such as operational convenience, mild reaction conditions, time and cost savings, oxidation effects without the need for chemical usage, and a reduction in environmental pollutants (Heo et al., 2021; X. H. Dong et al., 2024). EBI has demonstrated successful application in plant cellulose degradation (Bouchard, Méthot, & Jordan, 2006; Hwang, Park, Potthast, & Jeong, 2021; Ponomarev et al., 2011). Impurity removal and carbonyl group formation in cellulose were noticed in the previous study by EBI degradation (Henniges, Hasani, Potthast, Westman, & Rosenau, 2013). Moreover, EBI-degraded irradiated bacterial cellulose nanofibers (IBCNFs) exhibit a higher aspect ratio (micron scale), compared with nanoscale BNCFs (X. Z. Zhang et al., 2022), forming a three-dimensional network that enhances stabilization of Pickering emulsions while adsorbing at the oil-water interface (Wang et al., 2023). To our knowledge, the characteristics of the BC decreased by EBI and its emulsifying properties have not been reported. Thus, this research was significant for advancing green innovative approaches to BC degradation and reducing environmental pollution.

In this study, the IBCNFs were prepared by EBI and their properties were assessed. The emulsification ability and mechanism of IBCNFs prepared by different irradiation dosages were investigated. Additionally, the stability of IBCNFs-based Pickering emulsions was investigated by varying the concentrations of IBCNFs and oil phase contents. Furthermore, the tolerance of IBCNFs-stabilized Pickering emulsions under harsh environments (pH, ionic strength, and temperature) was also examined. This research provided environmentally friendly approaches to BC degradation, while offering a new pathway for achieving highly stable Pickering emulsions stabilized by BCNFs individually in the food industry.