## 1 Introduction
The consumer is increasingly aware that nutrition and health are closely interconnected and directly dependent on each other. The Mediterranean diet is a recognized formula for wellness and, starting from it, in recent years various European and extra-European campaigns have been aimed at inviting consumers to eat well and consume larger portions of fresh or minimally processed fruit and vegetables to maintain a good health status. Regarding blood orange juices, in this context, the consumer is increasingly persuaded to consume fresh or fresh-like products that maintain the health benefits and the nutritional and sensory characteristics of the fresh fruit. Accordingly, in the last two decades, scientific research has been committed to the experimentation and validation of new non-thermal technologies, defined as mild technologies, with the aim of achieving optimal microbial and enzymatic inactivation without producing thermal damage and variations in sensory and nutritional values of the fresh juice. All mild food technologies share the same main objectives: (i) ensuring microbiological safety, (ii) preserving nutritional and sensory quality, and (iii) being sustainable in terms of both investment costs and energy consumption. Some examples include ohmic and microwave heating, ultrasound, high-pressure carbon dioxide, high hydrostatic pressures, and high-intensity pulsed electric fields [9]. Among these non-thermal inactivation technologies, high hydrostatic pressure (HHP) and pulsed electric fields (PEFs) can be considered as the most investigated [10,11]. HHP offers great opportunities for food preservation, and at present, cold-extracted juices from fruit and/or vegetables stabilized with HPP technology are available on both national and international markets. Indeed, HPP application forces significant investment costs due to the high pressures required. High-intensity PEF involves the application of high-voltage electrical pulses for a very short time, generally less than a second. Microbial inactivation in the food, which is placed between two electrodes, is ensured by the electroporation and also electric lysis (dielectric breakdown) of the cell membrane of the microorganisms through the formation of electrical charges on the cell membrane itself [12]. For more than two decades, PEF processing effects on different fruit juices have been tested, with promising results for the inactivation of microbial communities and the preservation of nutritional and sensory characteristics of fresh fruit juices. Indeed, several authors evaluated PEF treatment efficacy by applying different operative parameters, such as electric field strength, number of pulses, pulse shape, pulse time, and total treatment time (t = number of pulses \(\times\) pulse duration), in lab-scale apparatuses or pilot plants, including series of static and continuous collinear treatment chambers in either continuous or batch mode [13; 14; 15; 16; 17; 18; 19; 20; 21]. It has also been demonstrated that this technology, in addition to preserving the nutritional and sensorial characteristics of the fresh product, can also improve its health potential as the electroporation, induced on the cells of the food itself, increases the extraction of bioactive constituents in the medium [22; 23]. In recent years, different commercial-scale systems have been released in the United States, European countries, and China [23]. However, large industrial-scale application of this technology still requires extensive research efforts. Indeed, besides the fact that PEF parameters must be optimized for each food matrix based on its conductivity (limited to low conductivity and air-bubble-free products), pH, type, concentration, and growth stage of the natural microflora, it is widely known that the main drawback of this technology is the ohmic heating due to the joule effect that can be generated under high-intensity PEF treatment, producing \"hot spots\" with adverse implications for the quality of food products, such as degradation of heat-sensitive bioactive compounds [24].