Honey raspberry juice, a popular beverage made from fresh raspberries and raw honey, is known for its rich bioactive compounds and distinct taste and texture (Farias et al., 2020). It effectively addresses the challenge of preserving fresh raspberries. However, the global issue of food spoilage, often caused by Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), poses significant food safety concerns (Hill et al., 2012; Raybaudi-Massilia et al., 2009) and can lead to severe human illnesses. Hence, the efficacy of sterilization techniques can be assessed using E. coli and S. aureus as key indicators. To meet FDA requirements, traditional thermal sterilization is widely adopted in the food industry due to its cost-effectiveness and minimal equipment and operator demands. Current thermal sterilization methods include ultra-high-temperature sterilization (Zhang et al., 2023a), microwave sterilization (Piasek et al., 2011) and ohmic sterilization (Tiravibulsin et al., 2021), among others. While thermal sterilization is effective at eliminating microorganisms and preserving juice quality during storage, it does result in the loss of vitamin C and flavor components, affecting the nutritional value and overall quality of the product. This fails to meet the consumer demand for natural, nutritious, and healthy juices. Consequently, alternative juice processing methods have emerged. Non-thermal sterilization approaches, such as induced electric fields (IEF) (He et al., 2021), high hydrostatic pressure (Xu et al., 2023), and plasma (Hou et al., 2019), have gained popularity as a new trend to meet the demands for food safety, extend the shelf life of food, and maintain its nutritional and sensory qualities.

In recent years, electrospray technology has emerged as a valuable method for creating a dynamic electric field that atomizes substances (Xie et al., 2015). It has found widespread applications in various fields, including biomedicine (Boda et al., 2018; Handan and Topuz, 2023), materials science (Jayasekara and Cebe, 2023), and chemistry (Anderson et al., 2007). In food processing, electrostatic atomization is commonly employed to produce uniform micron and nanoparticles. When used for sterilization, adjusting the parameters of the electrostatic spraying device allows for achieving electrostatic repulsion on the surface of droplets exceeding the surface tension, eventually leading to droplet fragmentation and the generation of charged microparticles or nanoparticles (Rosell-Llompart et al., 2018) Previous studies have shown that electrospray technology holds the potential for inactivating microorganisms and inhibiting enzymes (Wang et al., 2022; Wang et al., 2023a). In terms of inhibiting enzyme activity, electrospray technology was capable of altering the conformation of oxidases, resulting in the aggregation of enzyme molecules and subsequent reduction in their activity. In the context of microbial inactivation, electrospray technology was employed to disrupt intracellular enzyme activity, increase cellular permeability, and modify membrane potential, thereby influencing the normal metabolic processes and biological activities of bacteria. Importantly, this method has minimal impact on food quality and the environment, offers high safety, and shows promise for future applications. However, the traditional electrospray device primarily employs a high-voltage DC power supply and metal needles for laboratory-scale microbial inactivation, limiting its use to small batches. The challenge is how to industrialize this technology and enhance its inactivation efficiency. Therefore, we have modified the electrospray device to facilitate the large-scale application of this technology. The modified pressure spray combined with high-voltage electrospray (PS-ES) device not only homogenized and sterilized the liquid but also effectively resolved issues such as blockages due to sample viscosity and large particles, needle blockages, and low flow efficiency encountered in previous electrospray treatments. These improvements make the system more suitable for industrial production.

The enhanced PS-ES technology shows promise for the continuous, scalable, and efficient processing of honey raspberry juice. This study aimed to examine the inactivation mechanism of PS-ES on microorganisms in a simulated system by assessing microbial activity, membrane permeability, membrane integrity, membrane potential, and membrane structure. We also explored the impact of PS-ES treatment on the microbial activity and flavor of the honey raspberry juice application system. Furthermore, we discussed the alterations in microbial growth and color during storage at both 4 °C and room temperature over a 30-day period.