## 1 Introduction
The main advantages of microwave processing are minor changes in sensory quality, reduced enzymatic activity, shortened processing time, and the possibility of cooling the product as it flows [25; 26; 27; 28]. In the context of our work, the research aimed to comprehensively analyze the quality of the nutritional properties of apple-peach and apple-chokeberry juices, using an innovative multifunctional device as a novel tool for juice pasteurization. Our experiments focus on industrial-scale juice pasteurization. We utilized a specially designed prototype of a technological installation at Wosana Company. This installation was dedicated to pasteurizing juices and was crucial in production. The attempt to scale the process to an industrial level was evident in the use of this installation. Additionally, we compared two pasteurization technologies: microwave flow pasteurization and the traditional flow pasteurization process. These results make it possible to evaluate the effectiveness and efficiency of both methods on an industrial scale. The installation has practical applications in the food industry, particularly in juice production. This further confirms that our research has real industrial significance. Furthermore, comparing energy consumption between the innovative microwave pasteurization process and the traditional flow pasteurization process enables an assessment of energy optimization in an industrial context. Numerous studies have been conducted on the application of microwave flow methods in the processing of fruit juices. One of the latest studies is the work of [PERSON]. [29]. This research focused on a microwave heating system for orange juice, aiming to investigate the impact of microwave treatment as an alternative to conventional methods. The experiments were conducted at various temperatures, with a power of 900 W. The analysis of the physicochemical properties of orange juice showed a decrease in pH and a slight increase in acidity. The results also indicated higher temperatures raised the browning index, turbidity, and haze value. Different treatment methods did not significantly affect the Brix content, acidity, and pH during the holding phase. However, the rise in temperature accelerated the degradation rate of vitamin C.  
In another research conducted by [PERSON] et al., the authors used a hybrid technique that combines a microwave system with ultrasound [30]. The study aimed to inactivate Escherichia coli bacteria in orange juice. As part of the experiment, microwave power ranging from 300 to 900 W was applied for a variable processing time, ranging from 15 to 35 s, while the ultrasound exposure time was 10 to 30 min. Observations showed that the hybrid technique had a greater, more significant impact on the inactivation of E. coli compared to a substantial effect on the inactivation of _E. coli_ than the separate processing of each method. These studies have shown that combining ultrasound and microwave processing can be a potential alternative to traditional methods of processing beverages based on orange juice. It is also worth noting that a study by [PERSON] et al. showed that microwave heating technology can be an effective alternative to traditional heating methods [31]. These experiments were conducted on guava juice. In one experiment, 100 mL of guava juice was exposed to microwaves at 1450 MHz for 30 s. The results indicate that using the microwave method not only ensures the product's microbiological safety but also saves energy and reduces processing time while preserving the nutrients in juices and allowing products to retain their natural sensory properties.