Pulsed Electric Field Research Articles

Pulsed Electric Fields Effects on Proteins: Extraction, Structural Modification, and Enhancing Enzymatic Activity.

Pulsed electric field (PEF) is an innovative physical method for food processing characterized by low energy consumption and short processing time. This technology represents a sustainable procedure to extend food shelf-life, enhance mass transfer, or modify food structure. The main mechanism of action of PEF for food processing is the increment of the permeability of the cell membranes by electroporation. However, it has also been shown that PEF may modify the technological and functional properties of proteins. Generating a high-intensity electric field necessitates the flow of an electric current that may have side effects such as electrochemical reactions and temperature increments due to the Joule effect that may affect food components such as proteins. This article presents a critical review of the knowledge on the extraction of proteins assisted by PEF and the impact of these treatments on protein composition, structure, and functionality. The required research for understanding what happens to a protein when it is under the action of a high-intensity electric field and to know if the mechanism of action of PEF on proteins is different from thermal or electrochemical effects is underlying.

Treating Scars After Burns With Pulsed Electric Fields in the Rat Model.

Reducing scar size after severe burn injuries is an important and challenging medical, technological, and social problem. We have developed a battery-powered pulsed electric field (PEF) device and surface needle electrode applicator to deliver PEFs to the healing dorsal burn wound in rats. The pulsed electric field was used to treat residual burn wounds caused by metal contact in rats starting 10 days after the injury for 4 months every 11 or 22 days for 4 months using varying time applied voltages at 250-350 V range, 400 mA current, 40 pulses, 70 μs duration each, delivered at pulse repetition frequency 10 Hz at 5 locations inside the wound. We found 40%-45% reduction in the scar size in comparison with untreated controls in both upper and lower dorsal locations on rats' backs 2 months after the last PEF application. We have not detected significant histopathological differences in the center of the scars besides the thickness of the newly generated epidermis, which was thicker in the PEF-treated group. We showed that minimally invasively applied PEFs through needle electrodes are effective method and device for treating residual burn wounds in the rat model, reducing the size of the resulting scars, without any adverse reaction.

Development of an Ion Mobility Spectrometer Based on a Pulsed Photoelectric Effect Ionization Source.

Ion mobility spectrometry (IMS) is a compact and sensitive trace gas analysis instrument that ionizes the sample into ions for detection. Typically, an ion gate is used to cut the continuous ion beam into ion packets for separation and detection. However, commonly used ion gates suffer from complex structures or low ion transmission rates, making the gateless IMS a viable alternative. In this study, an IMS based on a pulsed photoelectric effect ionization source was designed. The photoelectrons were generated by irradiating a photoelectric material with a back-illuminated pulsed xenon lamp. This allows for low-energy photoelectron generation and the production of simple reactant ions (O2-(H2O)n) and thus negative product ions. The photoelectron current generated by this ionization source was analyzed, which can reach an intensity of a few microamperes and can be converted into an ion signal exceeding 10 nA. The introduction of the pulsed photoelectric effect ionization source makes it possible to generate separate ion packets and complete ion injection when a constant electric field is maintained in the ionization region. And with an assisted pulsed electric field in the ionization region, the resolving power of the system can be effectively improved to 1.85 times that of the constant electric field. The IMS developed in this study was used for the detection of common volatile hazardous chemicals, yielding effective results. The detection limit for phenol was below 1 ppb, and the dynamic response range exceeded 1 order of magnitude, which implies the potential applications of this IMS to detect substances with high electron affinity, such as explosives detection in public safety.

Integrating electromagnetic cancer stress with immunotherapy: a therapeutic paradigm.

An array of published cell-based and small animal studies have demonstrated a variety of exposures of cancer cells or experimental carcinomas to electromagnetic (EM) wave platforms that are non-ionizing and non-thermal. Overall effects appear to be inhibitory, inducing cancer cell stress or death as well as inhibition in tumor growth in experimental models. A variety of physical input variables, including discrete frequencies, amplitudes, and exposure times, have been tested, but drawing methodologic rationale and mechanistic conclusions across studies is challenging. Nevertheless, outputs such as tumor cytotoxicity, apoptosis, tumor membrane electroporation and leak, and reactive oxygen species generation are intriguing. Early EM platforms in humans employ pulsed electric fields applied either externally or using interventional tumor contact to induce tumor cell electroporation with stromal, vascular, and immunologic sparing. It is also possible that direct or external exposures to non-thermal EM waves or pulsed magnetic fields may generate electromotive forces to engage with unique tumor cell properties, including tumor glycocalyx to induce carcinoma membrane disruption and stress, providing novel avenues to augment tumor antigen release, cross-presentation by tumor-resident immune cells, and anti-tumor immunity. Integration with existing checkpoint inhibitor strategies to boost immunotherapeutic effects in carcinomas may also emerge as a broadly effective strategy, but little has been considered or tested in this area. Unlike the use of chemo/radiation and/or targeted therapies in cancer, EM platforms may allow for the survival of tumor-associated immunologic cells, including naïve and sensitized anti-tumor T cells. Moreover, EM-induced cancer cell stress and apoptosis may potentiate endogenous tumor antigen-specific anti-tumor immunity. Clinical studies examining a few of these combined EM-platform approaches are in their infancy, and a greater thrust in research (including basic, clinical, and translational work) in understanding how EM platforms may integrate with immunotherapy will be critical in driving advances in cancer outcomes under this promising combination.

Physicochemical, structural and functional properties of pomelo peel pectin extracted by combination of pulsed electric field and cellulase hydrolysis

In this study, pectin extracted from pomelo peel was investigated using three different combination methods of pulsed electric field (PEF) and cellulase. Three action sequences were performed, including PEF treatment followed by enzymatic hydrolysis, enzymatic hydrolysis followed by PEF treatment, and enzymatic hydrolysis simultaneously treated by PEF. The three corresponding pectins were namely PEP, EPP and SP. The physiochemical, molecular structural and functional properties of the three pectins were determined. The results showed that PEP had excellent physiochemical properties, with the highest yield (12.08 %), total sugar (80.17 %) and total phenol content (38.20 %). The monosaccharide composition and FT-IR analysis indicated that the three pectins were similar. The molecular weights of PEP, EPP and SP were 51.13, 88.51 and 40.00 kDa, respectively. PEP showed the best gel properties, emulsification stability and antioxidant capacity among the three products, due to its high galacturonic acid and total phenol content, appropriate protein and low molecular weight. The mechanism of PEF-assisted cellulase hydrolysis of pomelo peel was also revealed by SEM analysis. These results suggested that PEF pretreatment was the best method, which not only improved the efficiency of enzymatic extraction, but also reduced resource waste and increased financial benefits.

Effect of pulsed electric field on viability of Fusarium micromycetes

Effect of pulsed electric field on viability of Fusarium micromycetes

How pulse electric field treatment affects anti-nutritional factors and plant protein digestibility: A concise review

Consumption of foods rich in anti-nutritional factors (ANFs) can lead to inadequate absorption of vitamins and minerals. Pulsed electric field (PEF) treatment is a non-thermal food processing technology that uses short bursts of high voltage electric fields to induce structural modifications in biomolecules, including proteins, through electrochemical reactions and polarization of structural moieties. PEF offers potential benefits in enhancing the nutritional quality of food products by altering the structure and function of ANFs. However, the effects of PEF on ANFs in food have not been well established. Additionally, PEF-treated samples may undergo protein structural orientation modification due to electroporation and free radical species, potentially unfolding the native structure and influencing protein digestibility. Moreover, by increasing the mass transfer rate, electroporation can enhance the extraction of the initially trapped fractions into the solvent medium, which may include target compounds that affect protein functionality and digestibility. However, the protein digestibility of PEF-treated food products is yet to be thoroughly explored. Therefore, this review objectively investigates the possible mechanisms involved and the effectiveness of PEF in reducing different ANFs and modifying plant protein digestibility. This review also provides in-depth information about the possible applications of PEF-treated food items in the food industry.

Triboelectric Nanogenerators Using Recycled Disposable Medical Masks for Water Wave Energy Harvesting

AbstractIn the current daily life of people, the usage for disposable medical masks (DMMs) continues to be high. Discarded DMMs eventually become plastic pollution, threatening the marine environment seriously. At present, the common plastic recycling methods are extensive and not completely applicable for DMM recycling. In this work, according to the special structural and material characteristics of DMMs, a simple and effective recycling solution is proposed based on triboelectric nanogenerators (TENGs). First, a pulsed electric field system is designed and fabricated to treat the recycled films. The sterilizing rate reaches 91.8%, and the film surface potential is enhanced at the same time. Then, the feasibility of the treated films to be applied as the friction layers of TENGs is verified. Moreover, the recycled films are upgraded by chemical and physical methods, improving the output current of the basic TENG by 3.28 times. Finally, a complete TENG device is constructed to harvest water wave energy, 93.75% of which is made from recycled DMM materials. Under water waves, the power density of 18.22 W m−3 is achieved. Starting from TENG technology, this study combines circular economy and clean energy development, which is of significance for carbon neutralization.

Nanosecond pulse electric field treatment initiates mitochondrial apoptosis pathway by inducing mitochondrial morphological changes in myocardial cells.

As an emerging myocardial ablation technique, the mechanism of nanosecond pulse electric field (nsPEF) ablation is currently less studied. Mitochondria are one of the important membrane structure organelles in cells, participating in numerous life activities within the cell. This study aimed to explore the morphological changes of mitochondria in living cells following nsPEF treatment. Myocardial cells were treated with a self-made solid-state LTD high-voltage nanosecond pulse generator with a pulse width of 100ns for 80 times. The changes in mitochondrial membrane potential and cell apoptosis in rat myocardial cells after nsPEFs were investigated using JC-1 assay kit, apoptosis double staining assay kit, and mitochondrial fluorescence probe. The results showed that after nsPEF treatment, the mitochondrial membrane potential decreased, apoptosis increased, and the average mitochondrial area decreased from 0.48 µm2 in live myocardial cells to 0.16 µm2. The average circumference ranges from 3.17µm dropped to 1.60µm. The shape factor decreased from 1.92 to 1.41. The aspect ratio has decreased from 2.16 to 1.59. nsPEF treatment induces changes in the morphology of myocardial cell mitochondria. Based on the results of mitochondrial membrane potential and apoptosis, it can be inferred that under this equipment and parameter conditions, nsPEF treatment first causes changes in mitochondrial morphology, and then initiates the mitochondrial apoptosis pathway, which may provide experimental basis for investigating the potential mechanism of nsPEF ablation of myocardial cells.

Enhancing catechins, antioxidant and sirtuin 1 enzyme stimulation activities in green tea extract through pulse electric field-assisted water extraction: Optimization by response surface methodology approach

Green tea is an economic resource in Thailand because it is derived from smallholder agriculture and has expanded into food production. The purpose of this study is to optimize the parameters of pulsed electric field (PEF) assisted green tea extraction to produce a natural health product. A central composite design was involved to determine the effect of independent variables, including the intensity of electric field (I; 3–5 kV/cm), number of pulses (Np; 1000 to 3000 pulses) and green tea-to-water ratio (GT/W; 0.05–0.15 g/mL) on catechin (C), epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC) and epigallocatechin gallate (EGCG), total phenolic compound, antioxidant and sirtuin 1 enzyme stimulating activities. The results indicated that the Np had the most significant impact (p < 0.05) on the content of catechin and its derivatives and sirtuin 1 enzyme stimulating activity. The observations revealed that the I had a greater impact on antioxidant activities compared to the Np. The optimal conditions for PEF using the response surface method were determined to be I of 5 kV/cm, Np of 3000 pulses, GT/W of 0.14 g/mL and specific energy of 27 kJ/kg. Under the optimized conditions, the content of C, EC, ECG, EGC and EGCG were 7.34 ± 0.33, 11.26 ± 0.25, 3.75 ± 0.13, 7.53 ± 0.77 and 37.78 ± 0.58 mg/g extract, respectively. Furthermore, it was observed that green tea extract exhibited the ability to modulate the deacetylation activity of the sirtuin 1 enzyme, with a value of 22.63 ± 0.17 FIR. The results emphasized that the PEF led to achieving better responses compared to without pre-treatment using the PEF. Therefore, innovative technologies as PEF can be utilized for green tea extraction to produce natural ingredients, which can contribute to improved accessibility to healthcare. Additionally, the implementation of innovation techniques, such as PEF, in the extraction industry can enhance productivity growth and economic development.

Technical Feasibility and Safety of Image-Guided Biphasic Monopolar Pulsed Electric Field Ablation of Metastatic and Primary Malignancies

PurposeTo assess the technical feasibility and safety of image-guided percutaneous biphasic monopolar pulsed electric field (PEF) ablation of primary and metastatic tumors. Materials and MethodsWith institutional review board (IRB) approval and Health Insurance Portability and Accountability Act (HIPAA) compliance, this retrospective, single-institution study cohort of 17 patients (mean age, 53.5 years; range, 20–94 years) with overall progressive disease underwent 26 PEF ablation procedures for 30 metastatic (90%) and primary (10%) target lesions in the thorax (n = 20), abdomen (n = 7), and head and neck (n = 3). Concurrent systemic therapy was used in 14 of the 17 patients (82%). Follow-up imaging was scheduled for 1, 3, and 6 months after PEF ablation, and target and off-target lesion sizes were recorded. The overall response was assessed by the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria with imaging immediately before PEF serving as baseline. Adverse events (AEs) were determined by the Society of Interventional Radiology (SIR) classification. ResultsPEF ablation procedures were well tolerated and technically feasible for all 17 patients. The mean initial sizes of the target and off-target tumors were 2.6 cm (standard deviation [SD] ± 1.5; range, 0.4–6.9 cm) and 2.2 cm (SD ± 1.1; range, 1.0–5.2 cm), respectively. Overall, 15 of the 30 (50%) target lesions and 12 of the 24 (50%) off-target lesions were unchanged or decreased in size at the patient’s last follow-up. Eight patients had overall stable disease (47%) at the last follow-up. Of the 26 AEs, there were 9 mild (35%) and 1 moderate (4%) AE. ConclusionsAll PEF procedures were technically feasible with 1 moderate AE and stable disease for 47% of patients with a median follow-up period of 3 months.

Review on endobronchial therapies-current status and future.

There is a growing demand for lung parenchymal-sparing localized therapies due to the rising incidence of multifocal lung cancers and the growing number of patients who cannot undergo surgery. Lung cancer screening has led to the discovery of more pre-malignant or early-stage lung cancers, and the focus has shifted from treatment to prevention. Transbronchial therapy is an important tool in the local treatment of lung cancers, with microwave ablation showing promise based on early and mid-term results. To improve the precision and efficiency of transbronchial ablation, adjuncts such as mobile C-arm platforms, software to correct for computed tomography (CT)-to-body divergence, metal-containing nanoparticles, and robotic bronchoscopy are useful. Other forms of energy such as steam vapor therapy, pulsed electric field, and photodynamic therapy are being intensively investigated. In addition, the future of transbronchial therapies may involve the intratumoral injection of novel agents such as immunomodulating agents, gene therapies, and chimeric antigen receptor T cells. Extensive pre-clinical and some clinical research has shown the synergistic abscopal effect of combination of these agents with ablation. This article aims to provide the latest updates on these technologies and explore their most likely future applications.

Tissue Radiologic and Pathologic Response to Biphasic Pulsed Electric Field Technology in a Porcine Model

PurposeTo evaluate the radiologic, pathologic, and safety characteristics of a commercially available pulsed electric field (PEF) ablation system in a porcine model. Materials and MethodsMonopolar biphasic PEF ablation was delivered to the liver, kidney, and longissimus dorsi muscle through a single needle via a percutaneous or open approach with the Aliya System (Galvanize Therapeutics, Redwood City, California). Six animals were ablated and evaluated in 2 cohorts (Day 3 and Day 28). Muscle, kidney, and liver were ablated in each animal. Intraprocedural cone-beam computed tomography (CT), follow-up weekly CT, blood serology, gross pathology, and histopathology were performed to characterize the radiographic evolution and tissue response. ResultsThere were no adverse events and no findings of electrocardiographic abnormalities, and serologic values returned to baseline by Day 28. Ablation zones were visible on noncontrast CT images during follow-up. Most identified zones became radiographically smaller over time, with some fully resolved by Day 28. The relative decrease in gross ablation zone volume in the liver and skeletal muscle was 20% and 26%, respectively, whereas kidney sites grew by 22%. Ablation sites were focal and contained within the intended target tissue without extension to nontarget tissues or collateral structures. ConclusionsThe biphasic PEF system evaluated here resulted in a safe and predictable ablation response, with preservation of structural tissues in an animal model, offering an alternative to thermal ablative modalities, particularly near critical structures.

Enhancement of pork marinating efficiency through pulsed electric field pretreatment: Integration of parameter optimization, kinetic modeling and quality characteristics

Marination is an important part of meat processing, the disadvantage is that the process of marinating is slow and prone to losing nutrients. In this study, pork tenderloins were pretreated with pulsed electric field (PEF) before being immersed in the marinade at 4 °C. The aim was to investigate the effect of PEF pretreatment (PEFP) on the marination process, specifically mass transfer and the quality of the pork. Additionally, the response surface method (RSM) was employed to explore the optimal conditions for PEFP. Results showed that under the best condition (2 kV/cm, 141.2 Hz and 2.3% duty cycle), the NaCl content of pork cured for 6 h reached 3.31%, which could effectively shorten the marinating time of pork (up to 40%). After marinating for 6 h with PEFP, the weight, moisture, and salt changes increased significantly. The effective diffusion coefficient (De) was raised to 1.71 × 10−10 (PEFP) from 1.36 × 10−10 (control) and the kinetic model of mass transfer over time has good linear correlation. The scanning electron microscopy (SEM) results indicate that PEFP altered the muscle fibre structure of pork to some extent, resulting in loosely arranged muscle fibre bundles. The total bacterial colony count results showed that PEFP had a good sterilization effect on microorganisms in pork. Furthermore, PEFP does not alter the colour or pH of marinated pork while improving its tenderness. These results showed that PEFP could effectively promote salt diffusion to shorten marinating time and improve meat tenderness.

The Use of Bronchial Rheoplasty in Emphysema Patients Previously Treated with Endoscopic Lung Volume Reduction: A Case Series.

Endoscopic lung volume reduction (ELVR) is an established treatment option for patients with severe emphysema. Not all patients are candidates for this type of intervention, and in the context of significant airway secretions, they may be excluded from treatment. Bronchial Rheoplasty (BR) was developed to treat mucus hypersecretion by delivering nonthermal pulsed electric fields to the airway epithelium and submucosa. The literature to date demonstrates that patients treated with BR in clinical studies have a reduction in airway goblet cell hyperplasia as well as substantive clinical improvement in the setting of chronic bronchitis (CB). In this case series, we present four patients treated at three different institutions who had previously undergone ELVR with beneficial outcome. However, over time, these patients subsequently developed worsening clinical issues, including complaints of increased and thickened mucus, along with exacerbations in the setting of a loss of some ELVR-associated benefits. These patients then underwent exploratory treatment with BR with the intent of reducing their secretion burden and potentially restoring the efficacy associated with the initial placement of the airway valves. All BR procedures were well tolerated, and three of the four patients showed substantial improvement in their symptom burden. Airway examinations during the second of the two BR procedures also revealed what appeared to be less airway mucosal inflammation and a decrease in the quantity of airway secretions. Therefore, treatment with BR may have the potential to improve and restore the initial benefits associated with ELVR, thus enhancing long-term outcomes. Further clinical studies with sufficient follow-up are warranted to assess this in a larger cohort of patients, and to determine whether treatment with BR prior to ELVR may make more patients eligible for this treatment through reduction in their secretions and/or symptoms.

Pulsed electric field treatment applied to barley before malting reduces Fusarium pathogens without compromising the quality of the final malt

The growth of micromycetes and the associated production of mycotoxins during malting represents a potential safety issue and an economic challenge regarding the quality of beer as a product manufactured from malt. The treatment of malted cereals with a pulsed electric field (PEF) may be one method to overcome this issue. In this work were tested PEF conditions that would lead to a reduction in fungal growth without suppressing germination and thus causing deterioration in the technological parameters of the malt. Pre-soaking the grain for more than 3.5 h prior to PEF treatment was found to significantly reduce the germination energy and, compared to the untreated sample, enzymatic activity of the resulting malt. Therefore, a modification consisting of a short pre-soaking (10 min) and PEF treatment (field intensity 3.8 kV/cm, 100 pulses with peak width 20 μs) in a high conductivity environment (0.05 mol/L phosphate buffer) was implemented. This treatment led to a reduction (up to 80%) in growth of some Fusarium species (F. sporotrichoides and F. poae) and the production of corresponding mycotoxins, mainly trichothecenes A and ennianthins. Moreover, the treated malt did not differ significantly from the control malt in terms of enzymatic activity.

Tenderization of giant squid (Dosidicus gigas) meat pretreated with pulsed electric field and Asian seabass trypsin with the aid of vacuum impregnation

Giant squid (Dosidicus gigas) meat (GSM) generally has a tough texture, significantly lowering its acceptability by consumers. To enhance tenderness, GSM was pretreated with pulsed electric field (PEF) at 250 V for 5 min (PEF-GSM). Thereafter, PEF-GSM was soaked in partially purified trypsin (PPT) from pyloric caeca of Asian seabass obtained from ammonium sulfate precipitation (40%–60% saturation). The soaking was done at various concentrations of PPT (0, 5, 10 and 20 units/mL) with the aid of vacuum impregnation (VI) (2 cycles). Subsequently, PPT-soaked GSM samples were incubated at 60 °C for 5 and 10 min, followed by cooking at 100 °C for 2 min. For quality assessment, untreated cooked GSM (CON-GSM) was also prepared. Lightness of PEF-GSM samples increased (p < 0.05), compared to that of CON-GSM. After hydrolysis with PPT, myofibrillar proteins were degraded with coincidental upsurge in AAGC (α-amino group content). Protein degradation and AAGC became more pronounced with increasing PPT concentration and incubation time. PEF-GSM treated with PPT at 20 units/mL (PEF-GSM-20) and incubated for 10 min had the decreased firmness and toughness values, however its cooking loss slightly increased. Degradation of myofibrillar proteins was reconfirmed by FTIR spectra and microstructure alteration. PEF-GSM-20 with incubation at 60 °C for 10 min showed higher overall likeness score (p < 0.05), indicating a significant improvement in acceptability of consumers. Thus, combined application of PEF, PPT (20 units/mL) and VI before incubation at 60 °C for 10 min significantly enhanced the eating quality of GSM, making it more preferable for consumers.

Non-Thermal Technology Approaches to Improve Extraction, Fermentation, Microbial Stability, and Aging in the Winemaking Process

Research into non-thermal wine processing technologies is constantly evolving due to the increasing trend towards high-quality, minimally processed, and preservative-free wines. Technologies such as high-power ultrasound, high hydrostatic pressure, pulsed electric field, ultra-high pressure homogenization, and, more recently, cold plasma are some of the best examples currently being explored. This article provides an overview of the latest scientific research into these five non-thermal technologies and their current status in relation to winemaking. By exploring the potential applications of these technologies, it becomes possible to enhance extraction, shorten maceration time, inactivate microorganisms and oxidative enzymes, reduce the addition of chemical additives, accelerate aging, improve wine quality, and much more. However, further experiments are necessary to better comprehend the short- and long-term impacts on the overall quality of the wines produced, especially in terms of sensory characteristics and consumer acceptance. Optimizing processing conditions and scaling up are also of paramount importance to ensure better performance of these technologies at the various stages of winemaking. Additionally, a combined technologies approach has been highlighted as one of the future directions to overcome the limitations of processing with a single technology.

Exploring Conventional and Green Extraction Methods for Enhancing the Polyphenol Yield and Antioxidant Activity of Hyssopus officinalis Extracts.

Hyssopus officinalis L. (HO) is, as one of the most prevalently utilized plants, used in traditional medicine to cure various diseases as well as the in food and cosmetic industries. Moreover, HO is a rich source of polyphenols with potent antioxidant properties. However, the studies on the extraction of such compounds from HO are scanty and sparse. This study aims to optimize the extraction of polyphenols and maximize the antioxidant activity in HO extracts. A comprehensive experimental design was employed, encompassing varied extraction parameters to determine the most effective ones. Alongside conventional stirring (ST), two green approaches, the ultrasonic treatment (US) and the pulsed electric field (PEF), were explored, either alone or in combination. The extracted polyphenolic compounds were identified with a high-performance liquid chromatography-diode array detector (HPLC-DAD). According to the results, the employment of ST along with an ethanolic solvent at 80 °C for 150 min seems beneficial in maximizing the extraction of polyphenols from HO, resulting in extracts with enhanced antioxidant activity. The total polyphenol was noted at 70.65 ± 2.76 mg gallic acid equivalents (GAE)/g dry weight (dw) using the aforementioned techniques, and the antioxidant activity was noted as 582.23 ± 16.88 μmol ascorbic acid equivalents (AAE)/g dw (with FRAP method) and 343.75 ± 15.61 μmol AAE/g dw (with the DPPH method). The as-prepared extracts can be utilized in the food and cosmetics industries to bestow or enhance the antioxidant properties of commercial products.

Continuous pulsed electric field processing for intensification of aqueous extraction of protein from fresh green seaweed Ulva sp. biomass

The green marine macroalgae Ulva sp. can reach a high protein content and a high composition of essential amino acids. In this study, we have developed a novel device and investigated the parameters for a continuous Pulsed Electric Field (PEF) process, coupled with enzyme treatment followed by a spray drying, to facilitate the aqueous fractionation of Ulva protein. The process demonstrated 8.79 ± 0.58 (% w/w) protein extraction yield. Furthermore, the aqueous fractionation of protein exhibited a substantial 41.45% essential amino acid content and a branched amino acids composition of 17.58%. Additionally, it displayed an in vitro relative digestibility of 87.4 ± 1.36% compared to soy protein, along with a water holding capacity of 7.15 ± 0.17 g water/g sample and an oil holding capacity of 1.76 ± 0.11 g oil/g sample. These findings suggest that employing a continuous PEF process in conjunction with enzyme-induced cell wall degradation could position green marine macroalgae as an important potential source for food protein ingredients.