Pulsed Field Research Articles

Numerical Investigations into the Homogenization Effect of Nonlinear Composite Materials on the Pulsed Electric Field

Pulsed power equipment is often characterized by high energy density and field intensity. In the presence of strong electric field intensity, charge accumulation within insulators exacerbates electric field non-uniformity, leading to potential insulation breakdown, thereby posing a significant threat to the safe operation of pulsed power equipment. In this manuscript, we introduce nonlinear composite materials with field-dependent conductivity and permittivity to adaptively regulate the distribution of the pulsed electric field in insulation equipment. Finite-element modeling and analysis of the needle-plate electrodes and high-voltage bushing are carried out to comprehensively investigate the non-uniformity of the distribution of the electric field and the homogenization effect of various nonlinear materials in the presence of pulsed excitations of different timescales. Numerical results indicate that the involvement of nonlinear composite materials significantly improves the electric field distribution under pulse excitations. In addition, variations in the rising time of the pulses affect the maximum electric field intensity within the insulators considerably, but for pulses of nanosecond and microsecond scales, the tendencies are the opposite. Finally, via the simulations of the bushing, we illustrate that some measures proposed for improving the uniformity of the electric field under low frequencies, e.g., increasing the length of the electric field equalization layer and the distance of the underside of the electric field equalization layer from the grounding screen, are still effective for the homogenization of pulsed electric field.

Ventricular tachycardia ablation with pentaspline pulsed field technology in two patients with ischemic cardiomyopathy.

Due to its unique features, pulsed field ablation (PFA) could potentially overcome some limitations of current radiofrequency (RF) ventricular tachycardia (VT) ablation. However, data on the use of PFA in this setting are currently scarce. Two patients with ischemic cardiomyopathy and previously failed RF VT ablations were treated with PFA. A total of 18 bipolar applications (case1) and seven bipolar applications (case2) were delivered to the infero-lateral and infero-septal areas (case1) and to the apical lateral left ventricular (LV) wall (case2), placing the catheter adjacent to the LVwall in the flower configuration. A rapid cessation of VT and restoration of sinus rhythm were observed during PFA delivery in both cases. Further applications were delivered to achieve complete elimination of late potentials. In case 1, during the in-hospital stay, ECG monitoring did not show VT recurrences. Six-month follow-up was uneventful, with no VT recurrences at ICD interrogation. In case 2, due to postdischarge VT recurrences, a second RF procedure was scheduled 1 month later. The voltage map performed in sinus rhythm showed a low-voltage zone located at the anterolateral wall, near the previous ablation site. Numerous late potentials were recorded. At the 6-month follow-up, no further VT recurrences were documented after RF redo ablation. While the speed of application and potential transmural effect can facilitate the ablation of large diseased endocardial areas, early loss of contact due to difficult pentaspline catheter manipulation in the LV could lead to insufficient contact force and, consequently, inadequate energy penetration.

Pulsed dynamic electrolysis enhanced PEMWE hydrogen production: Revealing the effects of pulsed electric fields on protons mass transport and hydrogen bubble escape

The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway, with renewable energy-powered proton exchange membrane water electrolysis (PEMWE) emerging as the preeminent pathway for hydrogen production. Despite remarkable advancements in this field, confronting the sluggish electrochemical kinetics and inherent high-energy consumption arising from deteriorated mass transport within PEMWE systems remains a formidable obstacle. This impediment stems primarily from the hindered protons mass transfer and the untimely hydrogen bubbles detachment. To address these challenges, we harness the inherent variability of electrical energy and introduce an innovative pulsed dynamic water electrolysis system. Compared to constant voltage electrolysis (hydrogen production rate: 51.6 mL h−1, energy consumption: 5.37 kWh Nm−3 H2), this strategy (hydrogen production rate: 66 mL h−1, energy consumption: 3.83 kWh Nm−3 H2) increases the hydrogen production rate by approximately 27% and reduces the energy consumption by about 28%. Furthermore, we demonstrate the practicality of this system by integrating it with an off-grid photovoltaic (PV) system designed for outdoor operation, successfully driving a hydrogen production current of up to 500 mA under an average voltage of approximately 2 V. The combined results of in-situ characterization and finite element analysis reveal the performance enhancement mechanism: pulsed dynamic electrolysis (PDE) dramatically accelerates the enrichment of protons at the electrode/solution interface and facilitates the release of bubbles on the electrode surface. As such, PDE-enhanced PEMWE represents a synergistic advancement, concurrently enhancing both the hydrogen generation reaction and associated transport processes. This promising technology not only redefines the landscape of electrolysis-based hydrogen production but also holds immense potential for broadening its application across a diverse spectrum of electrocatalytic endeavors.

Investigate the relationship between pulsed field ablation parameters and ablation outcomes.

Pulsed field ablation (PFA) is an emerging non-thermal ablation method. The primary challenge is the control of multiple parameters in PFA, as the interplay of these parameters remains unclear in terms of ensuring effective and safe tissue ablation. This study employs the response surface method (RSM) to explore the interactions between various PFA parameters and ablation outcomes, and seeks to enhance the efficacy and safety of PFA. In vivo experiments were conducted using rabbit liver for varying PFA parameters: pulse amplitude (PA), pulse interval (PI), number of pulse trains (NT), and number of pulses in a pulse train (NP). Ablation outcomes assessed included three ablation sizes, surface temperature, and muscle contraction strength. Additionally, histological analysis was performed on the ablated tissue. We analyzed the relationship between PFA parameters and ablation outcomes, and results were then compared with those from a simulation using an electric-thermal coupling PFA finite element model. A linear relationship between ablation outcomes and PFA parameters was established. PA and NT exhibited extremely significant (P < 0.0001) and significant effects (P < 0.05) on all ablation outcomes, respectively. NP showed an extremely significant impact (P < 0.0001) on surface temperature and muscle contraction strength, while PI significantly influenced (P < 0.05) muscle contraction strength alone. Histological analysis revealed that PFA produces controlled, well-defined areas of liver tissue necrosis. Surface temperature results from simulations and experiments were highly consistent (R2 > 0.97). This study clarifies the relationship between various PFA parameters and ablation outcomes, and aims to improve the efficacy and safety of PFA.

Effect of freeze-thaw and PEF pretreatments on the kinetics and microstructure of convective and ultrasound-assisted drying of orange peel

The main waste generated by juice industry comprises orange peels, which have a great upcycling potential once stabilized. Drying is the most used method for this purpose, but the high energy consumption prompts interest in its intensification. This study assessed the influence of freeze-thaw and pulsed electric field (PEF) pretreatments in conventional and airborne ultrasound-assisted drying (50 °C) of orange peels. None of these pretreatments alone got to reduce processing times significantly, but combined with ultrasound-assisted drying produced a significant shortening of the process. This was particularly important in the lower intensity PEF pretreatment tested (0.33 kJ/kg), indicating the existence of optimum conditions to carry out the pretreatments. Microstructure analysis revealed that the application of ultrasound during drying led to better preservation of the sample structure. Thus, the integration of pretreatment techniques to ultrasound-assisted drying may not only shorten the process but also help to preserve the original structure.

Advancements in Non-Thermal Processing Technologies for Enhancing Safety and Quality of Infant and Baby Food Products: A Review.

Breast milk is the main source of nutrition during early life, but both infant formulas (Ifs; up to 12 months) and baby foods (BFs; up to 3 years) are also important for providing essential nutrients. The infant food industry rigorously controls for potential physical, biological, and chemical hazards. Although thermal treatments are commonly used to ensure food safety in IFs and BFs, they can negatively affect sensory qualities, reduce thermosensitive nutrients, and lead to chemical contaminant formation. To address these challenges, non-thermal processing technologies such as high-pressure processing, pulsed electric fields, radio frequency, and ultrasound offer efficient pathogen destruction similar to traditional thermal methods, while reducing the production of key process-induced toxicants such as furan and 5-hydroxymethyl-2-furfural (HMF). These alternative thermal processes aim to overcome the drawbacks of traditional methods while retaining their advantages. This review paper highlights the growing global demand for healthy, sustainable foods, driving food manufacturers to adopt innovative and efficient processing techniques for both IFs and BFs. Based on various studies reviewed for this work, the application of these novel technologies appears to reduce thermal processing intensity, resulting in products with enhanced sensory properties, comparable shelf life, and improved visual appeal compared to conventionally processed products.

Overview of physics results from the ADITYA-U tokamak and future experiments

The ADITYA upgrade (ADITYA-U), a medium-sized (R0=75 cm,a=25 cm) conventional tokamak facility in India, has been consistently producing experiments findings by using circular and shaped-plasmas. Recognizing the plasma parameters aligning closely with the design parameters of circular limited plasmas, ADITYA-U shifted its focus toward exploring the operational regime for experimentation on saw-tooth and MHD phenomena. Moreover, ADITYA-U has made consistent advancements toward conducting preliminary plasma shaping experiments through the activation of top and bottom divertor coils utilizing hydrogen as well as deuterium fuels. Confinement is improved by a factor of ∼1.5 in D2 plasmas when compared to H 2 plasmas of ADITYA-U. Further, ADITYA-U operations emphasize preventing disruptions and runaway electrons (REs) to ensure safe operations for future fusion devices. Significant suppression of REs has been achieved in ADITYA-U with the application of pulsed localized vertical magnetic field (LVF) perturbation, thereby establishing the technique’s independence from the tokamak device. The successful RE mitigation requires a critical threshold of LVF pulse magnitude, which is approximately 1% of the toroidal magnetic field, and a minimum duration of ∼5 ms. Apart from this, several novel findings have been achieved in the ADITYA-U experiments, including the modification of sawtooth duration through gas-puff, the emergence of MHD-induced geodesic acoustic mode-like oscillations, the propagation of fast heat pulses induced by MHD activity, the control of RE dynamics through Gas-puffs, the propagation of pinch-driven cold-pulses, the transport and core accumulations of argon impurities, the mass dependency of plasma toroidal rotation and the detection of ‘RICE’ scaling, as well as the characterization of edge plasma using wall conditioning methods, such as glow discharge cleaning using a combination of Ar-H 2 mixture, localized wall cleaning by electron cyclotron resonant plasma, and the development of machine learning-based disruption predictions, will be discussed in this paper.

Protein enrichment of the red macroalga Palmaria palmata using pulsed electric field and enzymatic processing

Protein enrichment of the red macroalga Palmaria palmata using pulsed electric field and enzymatic processing

First Report of Bean Leafroll Virus in Pea and Chickpea, in Canada.

Bean leafroll virus (BLRV; Bean leafroll virus), a single-stranded RNA virus in the genus Luteovirus, is phloem-limited and primarily transmitted by aphids in a non-propagative, persistent manner (Rashed et al., 2018; Kidanemariam and Abraham, 2023). BLRV infects various legumes and has been reported from major pulse-growing regions worldwide (Agindotan et al., 2019) but not in the Canadian Prairies. Its impact on crop yield varies with plant and virus genotypes and the timing of infection. Some pea fields have experienced disease rates of up to 80% (Clement et al., 2020; Hampton, 1983). Throughout the 2022 growing season (June and July), pulse fields from across Saskatchewan were randomly selected and surveyed, and symptomatic plants demonstrating leaf yellowing and chlorosis were collected and stored at -80°C before processing. Observed symptoms included necrotic spots, chlorosis, leaf mottling, leaf rolling in peas, severe bright yellowing, and leaf marginal necrosis in chickpeas. BLRV detection was performed on 35 leaves of the collected samples using both Enzyme-Linked Immunosorbent Assay (ELISA) and Reverse transcription polymerase chain reaction (RT-PCR). ELISA testing followed the manufacturer's protocol using a commercial kit (Nano Diagnostics, San Jose, CA, USA). Total RNAs were extracted from the frozen samples using TRIzol (Invitrogen, Carlsbad, CA, USA). For the detection of the diverse BLRV isolates, sequences of various isolates were aligned and primers were specifically designed in-house, targeting the virus's highly conserved regions on the GP3 and 3' UTR (see Supplementary material). Additional primers were also designed targeting coat protein (CP) coding regions which were previously used for BLRV detection (Agindotan et al. 2019; Larsen & Webster 1999). PCR testing of 35 symptomatic samples including 12 pea plants and 23 chickpea plants, identified the presence of BLRV in two symptomatic samples, one each from a field pea (Pisum sativum L. var. CDC Inca) and a desi-type chickpea (Cicer arietinum L. var. CDC Leader). The infected pea and chickpea samples were found in Saskatoon, SK (Coordinates: 52°9'27''N,106°34'14"W), and the Leader area, southwest of Saskatchewan, SK (Coordinates: 50°52'14"N,109°23'11"W), respectively. PCR amplicons were purified and sent for Sanger sequencing. The reads were assembled to generate 1666 and 323 nucleotides from pea and chickpea, respectively, with a minimum of 2X coverage. Partial nucleotide sequences of the BLRV isolates obtained from pea (PsSK1) and chickpea (CaSK1) (GenBank accession numbers: PP240429, PP266588) showed (1521/1574 bp) 96.63% and (316/323 bp) 97.83% similarity with a BLRV reference isolate sequence (NC_003369) and to an isolate from Argentina (KR261610) which was reported on Medicago sativa L. with (1555/1574 bp) 98.79% and (319/323 bp) 98.76% similarity, correspondingly. Both infected samples were confirmed to be BLRV-infected through the ELISA and exhibited a high interaction ratio (PsSK1: 0.319 and CsSK1: 0.245) compared to a positive control (0.292) after 30 minutes as measured at 450 nm. This is the first report of BLRV in the pulse-growing region of the Canadian Prairies. In Saskatchewan, there is no history of BLRV despite the large amount of area growing susceptible crops. Therefore, the survey project that this study was part of was not intended to evaluate the severity of BLRV but rather to determine if there is any virus present that might have been overlooked. The samples were therefore taken randomly, with a focus on the number of fields and geographic coverage rather than focusing on multiple plants per field. Moreover, fields were not chosen based on symptoms but rather at random. Although, plants within fields were chosen because they displayed symptoms. Typically, a disease note includes estimates of severity and potential risk; however, that is not possible for this study. Rather, the fact that it was detected indicates a greater risk than previously perceived, since it was assumed that BLRV was not present. These findings highlight the need for further research on the virus's current status, its impact on crop production, and the resistance of pulse varieties grown in Saskatchewan.

Combined pulsed electric field-ultrasound assisted extraction of yarrow phenolic-rich ingredients and their nanoliposomal encapsulation for improving the oxidative stability of sesame oil

In this research, yarrow phenolic-rich extract was produced using pulsed electric field (PEF)-ultrasound assisted technology. The highest extraction efficiency (5.99 %) was obtained at 6.25 kV/cm of PEF and the sonication time of 60 min. As the PEF intensity and sonication time rose, the total phenolic content (TPC) and ferric-reducing power (RP) of the extracts increased. The PEF intensity of 2.70 kV/cm and sonication time of 45.83 min were the optimum extraction conditions resulting in the highest extraction efficiency, TPC, and RP. Then, this optimum extract was loaded into nanoliposomes. At higher extract levels, the encapsulation efficiency lowered, while the particle size, polydispersity index (PDI), and zeta potential of the nanoliposomal samples elevated. The results of Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) confirmed the successful encapsulation of yarrow extract into nanoliposomal carriers; the sample containing the extract had the highest enthalpy (3600 J/g) and nanoliposomes loaded with yarrow antioxidant extract (0.11 mL/mg) was the optimum sample. Finally, the sesame oil containing 500 ppm free and nanoliposome extract, as well as the sample with 200 ppm BHT were evaluated for oxidative stability. The highest oxidation stability (14.21 h) belonged to the oil containing nanoliposomal yarrow phenolic extract.

Selective extraction of biomolecules from Saccharomyces cerevisiae assisted by high-pressure homogenization, pulsed electric fields, and heat treatment: Exploring the effect of endogenous enzymes

Saccharomyces cerevisiae contains valuable compounds sought by the industry, prompting the exploration of effective extraction methods. Three physical methods were compared—High-Pressure Homogenization (HPH), Pulsed Electric Fields (PEF), and Heat Treatment (HT)—for releasing diverse bioproducts (amino acids, glutathione, proteins, and mannoproteins) from S. cerevisiae. Treatments (HPH: 2 passes at 100 MPa, PEF: 15 kV/cm for 100 μs (44.9 kJ/kg), HT: 60 °C for 5 min) affected over 90% of S. cerevisiae cells. Despite permeabilization, HT exhibited low efficacy in releasing compounds. HPH led to complete cell disruption, extracting maximum glutathione (1.09 ± 0.04 g/100 gdw) and proteins (68.95 ± 0.96 g/100 gdw) after 2 h. PEF facilitated the gradual extraction of low molecular weight compounds while leaving high molecular weight compounds unreleased initially. After 48 h, 72% of the total protein and amino acid content was released through hydrolysis catalyzed by endogenous yeast proteases. Furthermore, 64.1% of mannoproteins were obtained after 72 h of incubation. This study highlights the efficacy, scalability, and industrial potential of HPH and PEF, demonstrating their ability to produce tailored extracts over time and underscoring the significant role of endogenous enzymes in optimizing extraction yields. These findings provide valuable insights for enhancing efficiency and sustainability in bioproduct extraction from S. cerevisiae.

The effect of electromagnetic fields on tendinopathies : Study on the effect analysis of asingular application of high-energy pulsed electromagnetic fields

Tendinopathies are diseases that often entail long-term treatment consisting of analgesics, physiotherapy, orthotics, and sparing. The aim of this study was to investigate the effect of asingle application of ahigh-energy PEMF (pulsed electromagnetic field) on pain perception and blood born inflammation parameters. 34patients were randomly assigned to averum group (10 min PEMF, 0,78 T) or aplacebo group (10 min sham condition). Prior to and up to one week after the patient blinded treatment (t1-t5), local pain state was assessed by means of algometry as pain pressure threshold (PPT). Accordingly, heat-shock protein70 (HSP70) levels were analysed. Statistical analyses included 2‑way ANOVA (2 × 5). The clinical trial was registered (DRKS00031321). After randomization and drop-out (verum n = 17, placebo n = 13) baseline-analyses did not reveal significant between-group differences for PPT (p = 0,096), for HSP70 (p = 0,524), or any other sample characteristics (p > 0,05). Pain reduction during one week of observation showed to be significantly higher (p = 0,045, η2 = 0,013) for the PEMF group (PPT: +83 bis +139%) compared to the placebo group (PPT: +10 bis +36%). There were no HSP70 associated effects. Asingle bout of high energy PEMF led to an immediate pain relief in tendinopathy patients lasting at least for one week, but the hypothesized underlying HSP70 associated inflammatory pathway could not be confirmed.

Pacific white shrimp (Litopenaus vannamei) treated with chitooligosaccharide-catechin conjugate with the aid of prior pulse electric field and vacuum impregnation: Quality and microbial diversity during refrigerated storage

Quality of Pacific white shrimp (PWS) soaked in chitooligosaccharide-catechin (CHOS-CAT) conjugate at varying concentrations (1.0 and 2.0%, w/v) and those treated with CHOS-CAT conjugate at aforementioned concentrations with the aid of pulsed electric field (PEF) and vacuum impregnation (VI) was studied when stored at 4 °C for 15 days. Among all treatments, a lower melanosis score of 7 was found in the samples when pre-treated with PEF, followed by soaking in CHOS-CAT conjugate at 2% (w/v) with VI (CC-PV-2) than other samples after 15 days of storage (p < 0.05). Total viable bacteria, psychrotrophic bacteria, presumptive Pseudomonas, Vibrio parahaemolyticus, other Vibrio sp., H2S-producing bacteria, and Enterobacteriaceae counts of CC-PV-2 were lower than other samples at the end of storage (day 15). CC-PV-2 exhibited the lowest TVB-N and TMA-N contents, PV, and TBARS value when compared to the control and other treated samples throughout the storage (p < 0.05). Polyunsaturated fatty acids were retained at a substantial amount in the CC-PV-2 at the end of storage. In addition, next generation sequencing revealed a low percentage of spoilage bacteria such as Shewanella and Pseudomonas and pathogenic bacteria namely Vibrio sp. in the CC-PV-2. Also, CHOS-CAT conjugate showed hydrogen bonding with various targeted proteins of bacteria, as elucidated using molecular docking, verifying its bacterial inhibitory potential. CC-PV-2 had a shelf-life of at least 12 days, while the control could be kept only for 3 days. Overall, the application of CHOS-CAT conjugate with the aid of PEF and VI led to the enhanced quality and extended shelf-life of refrigerated PWS.

Industrial Production of Bioactive Nutrient-Enhanced Extra Virgin Olive Oil under Continuous-Flow Ultrasound and Pulsed Electric Field Treatment.

Extra virgin olive oil (EVOO) is a cornerstone of the Mediterranean diet. Many studies have highlighted its crucial preventive role against cardiovascular disease, neurodegenerative disorders, metabolic syndrome and cancer, with these effects being due to the synergistic anti-inflammatory and antioxidant activities of minor components, such as polyphenols and tocols. The aim of the present study is to implement new technologies for olive oil mills and develop an efficient large-sized industrial process for the continuous extraction of healthier EVOOs that are enriched with these bioactive compounds. Non-thermal technologies, namely ultrasound (US) and pulsed electric field (PEF), have been tested, separately and in combination, to eliminate the need for traditional malaxation. There is extensive literature to support the efficacy of ultrasound-assisted extraction (UAE) and PEF treatments in EVOO production. A newly designed US device and a PEF industrial chamber have been combined into a single, integrated continuous-flow setup, the performance of which in the extraction of EVOO from green Coratina olives has been evaluated herein. Extraction yields, physico-chemical and organoleptic characteristics, and polyphenol and tocol contents were monitored throughout the trials, and the last three were measured at accelerated aging times (AAT) of 15 and 30 days. The US and combined US-PEF processes not only increased daily oil production (ton/day, by nearly 45%), but also eliminated the need for kneading during malaxation, resulting in significant energy savings (approximately 35%). In addition, these innovations enriched the resulting EVOO with nutritionally relevant minor components (8-12% polyphenols, 3-5% tocols), thereby elevating its quality and market value, as well as overall stability. The introduction of continuous-flow US and PEF technologies is a remarkable innovation for the EVOO industry, as they offer benefits to both producers and consumers. The EVOO resulting from non-thermal continuous-flow production meets the growing demand for healthier, nutrient-enriched products.

Chemical and Thermal Characteristics of PEF-Pretreated Strawberries Dried by Various Methods.

By increasing the permeability of the cell membrane of the treated material, pulsed electric fields (PEF) enhance the internal transport of various chemical substances. Changing the distribution of these components can modify the chemical and thermal properties of the given material. This study aimed to analyze the impact of PEF (1 kV/cm; 1 and 4 kJ/kg) applied to strawberries prior to drying by various methods (convective, infrared-convective, microwave-convective, and vacuum) on the chemical and thermal properties of the obtained dried materials (sugars content, total phenolic content, and antioxidant capacity (ABTS and DPPH assays); thermal properties (TGA and DSC); and molecular composition (FTIR)). PEF could have induced and/or enhanced sucrose inversion because, compared to untreated samples, PEF-pretreated samples were characterized by a lower share of sucrose in the total sugar content but a higher share of glucose and fructose. Reduced exposure to oxygen and decreased drying temperature during vacuum drying led to obtaining dried strawberries with the highest content of antioxidant compounds, which are sensitive to these factors. All PEF-pretreated dried strawberries exhibited a lower glass transition temperature (Tg) than the untreated samples, which confirms the increased mobility of the system after the application of an electric field.

Modeling methods in overlapping electroporation treatments: Pulse number effects on tissue conductivity and ablation area

Irreversible electroporation (IRE) is a non-thermal tissue ablation technique that utilizes high-voltage pulses between electrode pairs to destroy tissue. Numerical models are essential for predicting treatment outcomes and aiding in treatment planning. This paper studies a nonlinear conductivity model (NC) and a multiparametric nonlinear conductivity model (MPNC) to investigate overlapping electroporation treatments using a three-needle electrode configuration. The NC model accounts for the effects of the electric field and temperature on tissue conductivity during multiple pulsed electric field applications. The MPNC model incorporates the influence of pulse number, alongside electric field and temperature, on tissue conductivity. Results indicate that in the MPNC model, tissue conductivity is significantly higher in regions where the electric field intensity is below the threshold for irreversible electroporation, with the maximum difference reaching 0.4S/m. In contrast, tissue conductivity is slightly lower in regions where the electric field intensity exceeds the IRE threshold. Additionally, the MPNC model predicts a smaller area of irreversible electroporation and a larger area of reversible electroporation, with these differences becoming more pronounced as the distance between electrode needles increases. These findings underscore the importance of considering pulse number effects in numerical models to enhance the accuracy of treatment planning for irreversible electroporation-based therapies.

Pulsed Electric Field as a Mild Treatment for Extended Shelf-Life and Preservation of Bioactive Compounds in Blood Orange Juice

The agri-food processing industry predominantly relies on fossil fuels, contributing significantly to greenhouse gas emissions and extensive water use. Climate change requires a conversion of food processing technologies towards sustainability. Our research focuses on testing and validating pulsed electric field (PEF) technology as a mild processing method for stabilizing freshly squeezed, not from concentrate, blood orange juice. Experiments were carried out on a continuous pilot plant endowed with a patented treatment chamber that ensures a constant flow of product without “hot spots” for a homogeneous treatment. Once the operative conditions of the process in terms of energy density were optimized, PEF-treated blood orange juice was tested in order to evaluate the effects on physico-chemical parameters (total soluble solids, total acidity, pH, CIE L*, a*, b*, C*, h color indices, cloud, bioactive compounds (ascorbic acid, total anthocyanins, total and individual flavanones), antioxidant activity (ORAC units, total phenolic content), microbial communities (aerobic mesophilic viable count, yeasts and molds, acid-tolerant microorganisms), residual enzymatic pectinmethylesterase activity, and sensory attributes (flavor, off-flavor, off-odor, color, intensity of odor, acidity, sweetness, bitter, freshness, cooked flavor). Then, in order to simulate the commercial refrigerated distribution of PEF-treated blood orange juice and define its refrigerated shelf-life, the PEF-treated freshly squeezed, not from concentrate, blood orange juice was subjected to physico-chemical, antioxidant, microbiological, and sensory evaluations over twenty days of refrigerated storage at 4 ± 1 °C. The PEF treatment effectively ensured excellent microbial inactivation and enhanced the nutritional and health characteristics of the juice, thereby extending its shelf-life. This study demonstrates the significant potential of the PEF treatment to produce blood orange juice suitable for a new retail segment—freshly squeezed juices with superior health quality, fresh-like characteristics, and extended refrigerated shelf-life.

Evaluation of pulsed field ablation lesion characteristics using an in vitro vegetable model.

In vitro models to evaluate cardiac pulsed field ablation (PFA) have not been well established. We sought to create a standardized vegetable model and staining protocol for assessing unipolar PFA using a surface electrode. We exposed potato slabs to unipolar PFA in a saline bath using a 3.5mm electrode catheter and grounding pad connected to a custom-built high-voltage generator. Lesions were clearly visualized after staining with 2,3,5-triphenyltetrazolium chloride (TTC) using a timed protocol to reveal a necrotic center and a periphery of electroporated cells with intact mitochondria. Lesion volume increased linearly with increasing voltage and logarithmically with repetitive PFA applications. The findings observed in this vegetable model using a TTC staining protocol are consistent with findings observed with cardiomyocytes.

P269. Lumbar spine fusion rates increased by utilizing pulsed electromagnetic field stimulation (PEMF) devices as an adjunct to surgery

P269. Lumbar spine fusion rates increased by utilizing pulsed electromagnetic field stimulation (PEMF) devices as an adjunct to surgery

In Vitro Assay Development to Study Pulse Field Ablation Outcome Using Solanum Tuberosum.

Exposing cells to intense and brief electric field pulses can modulate cell permeability, a phenomenon termed electroporation. When applied in medical treatments of diseases like cancer and cardiac arrhythmias, depending on level of cellular destruction, it is also referred to as irreversible electroporation (IRE) or Pulsed Field Ablation (PFA). For ablation device testing, several pulse parameters need to be characterized in a comprehensive manner to assess lesion boundary and efficacy. Overly aggressive voltages and application numbers increase animal burden. The potato tuber is a widely used initial model for the early testing of electroporation. The aim of this study is to characterize and refine bench testing for the ablation outcomes of PFA in this simplistic vegetal model. For in vitro assays, several pulse parameters like voltage, duration, and frequency were modulated to study effects not only on 2D ablation area but also 3D depth and volume. As PFA is a relatively new technology with minimal thermal effects, we also measured temperature changes before, during, and after ablation. Data from experiments were supplemented with in silico modeling to examine E-field distribution. We have estimated the irreversible electroporation threshold in Solanum Tuberosum to be at 240 V/cm. This bench testing platform can screen several pulse recipes at early stages of PFA device development in a rapid and high-throughput manner before proceeding to laborious trials for IRE medical devices.