High Voltage Electrostatic Field Research Articles

Biochemistry behind firmness retention of jujube fruit by combined treatment of acidic electrolyzed water and high-voltage electrostatic field.

Harvested jujube (Zizyphus jujuba Mill) is prone to softening due to active metabolism. This study investigated the effects of acidic electrolyzed water (AEW), high-voltage electrostatic field (HVEF) and their combination (AEW+HVEF) on softening and associated cell wall degrading enzymes (CWDEs), cell membrane integrity and antioxidant system of 'Huping' jujube during storage at 0±1°C. The results indicated that fruit subjected to AEW+HVEF, AEW or HVEF treatments maintained firmness 15.7%, 10.7%, and 5.3% higher than that of untreated control fruit at the end of 90days cool storage. Fruit treated with AEW+HVEF could better maintain cell membrane integrity and exhibit lower activities of CWDEs and higher antioxidant capacity than that treated with either AEW or HVEF. Correlation analysis suggested that inhibition of softening was associated with reduction of CWDEs activities, and maintenance of membrane integrity and antioxidant system.

Valorization of meat and bone residue by ultrasound and high voltage electrostatic field assisted two-stage enzymatic hydrolysis: Nutritional characteristics and flavor analysis

Enzymatic hydrolysis has been used to extract protein and bioactive compounds. Choosing appropriate enzymes can improve the hydrolysis of meat and bone proteins and enhance the flavor of the final product. In this study, the by-products of meat and bone residue after cooking in food processing plants were hydrolyzed by a two-stage method of complex protease (neutral protease, flavor protease and alkaline protease), and the effects of ultrasound (US) and high voltage electrostatic field (HVEF) pretreatment before enzymatic hydrolysis on the nutritional characteristics and flavor of the enzymolysis solution were investigated. The results showed that pretreatment by US alone and combined with US and HVEF could promote proteolysis and increase the content of free amino acids. HVEF pretreatment alone had no significant effect on protein hydrolysis. The enzymatic hydrolysate pretreated by US-HVEF had the strongest umami flavor, the highest flavor nucleotide content and the strongest antioxidant capacity. And electronic nose and GC-MS analysis showed that the combination of US-HVEF pretreatment could enhance the flavor characteristic intensity of enzymatic hydrolysate and increase the volatile compound content, but the compound types decreased slightly. Therefore, physical field pretreatment before enzymatic hydrolysis can help to produce high value-added enzymatic hydrolysis products.

Effects of high voltage electrostatic field and weak magnetic field assisted refrigeration on preservation of spinach

Effects of high voltage electrostatic field and weak magnetic field assisted refrigeration on preservation of spinach

Intermittent high voltage electrostatic field and static magnetic field assisted modified atmosphere packaging alleviate mildew of postharvest strawberries after simulated transportation by activating the phenylpropanoid pathway

The mildew is a typical symptom of strawberries during storage. The effectiveness of intermittent high voltage electrostatic field combined with static magnetic field (HVEF-SMF) technique in inhibiting the mildew of strawberries (before and after simulation of transport vibrations) was investigated. Intermittent HVEF, SMF and HVEF-SMF treatments inhibited spoilage fungal growth on the surface of strawberries by increasing the membrane permeability and leakage of intracellular materials of spoilage fungal. The HVEF-SMF alleviated mildew in strawberries, which probably via the increase of antifungal compounds (total phenolics and lignin), phenylpropanoid biosynthetic enzyme activities (Phenylalanine ammonia-lyase, 4-coumarate-CoA ligase) and pathogenesis-related proteins enzymes activities (chitinase and β-1,3-glucanase). Overall, HVEF-SMF contributed to alleviating the mildew and disease incidence of strawberries, improving the levels of antimicrobial activity, as well as extending their shelf life from 6 d to 12 d. Therefore, HVEF-SMF treatment is a promising technology for alleviating postharvest mildew in strawberries after transportation.

Hierarchical Cellulose Aerogel Reinforced with In Situ-Assembled Cellulose Nanofibers for Building Cooling.

The development of new structural materials for passive daytime radiative cooling (PDRC) of buildings will significantly reduce global building energy consumption. Cellulose aerogels are potential PDRC materials for building cooling, but the cooling performance and mechanical strength of cellulose aerogels are considered as challenges for their practical applications. Herein, a bio-inspired hierarchically structured cellulose aerogel (HSCA) was fabricated through an assembly strategy assisted by a high-voltage electrostatic field. The HSCA possesses outstanding PDRC performance and moderate mechanical strength owing to aligned hierarchical porous network microstructures reinforced with in situ-assembled crystalline cellulose nanofibers. Promisingly, the HSCA achieves a max cooling temperature of 7.2 °C and exhibits 1.9 MPa axial compressive strength. There was no significant cooling performance degradation after the hydrophobically modified HSCA was placed outdoors for 3 months. A simulation of potential cooling energy savings shows that by using HSCA as the building envelopes (side wall and roof), it can save 52.7% of cooling energy compared to the building baseline consumption. This new strategy opens up the possibility of developing advanced functionally regenerated cellulose aerogel, which is expected to provide a revolutionary improvement in aerogel materials for building cooling.

Physicochemical properties of rainbow trout (Oncorhynchus mykiss) filet treated with high-voltage electrostatic field under different storage temperatures

The post-mortem rigid of farmed rainbow trout (Oncorhynchus mykiss) affects the texture of the meat and might even be risky for microorganisms, undermining the popularity of frozen filets among consumers. This study investigated the importance of different conditions (0°C, 4°C, and 25°C for 0–4 days) and physicochemical characteristics of rainbow trout filet storage on fish’s characteristics, freshness, quality, and shelf-life. Results showed that the fish easily underwent rigor mortis and resolution of rigor mortis when stored at 25°C. However, rigor mortis was more likely to occur under storage at 0°C than at 4°C [with 100 kV/m high voltage electrostatic fields (HVEF)] due to low-temperature stimulation, but resolution of rigor mortis began to appear after 24 h of storage at either temperature. The protein solubility and gel strength of fish stored at 25°C continued to decrease due to thermal denaturation, and those of fish stored at 4°C and 0°C also showed a decrease owing to rigor mortis and then an increase when rigor mortis disappeared. The K values increased rapidly at 25°C and reached 61% at 14 h. Under storage at 4°C and 0°C, the K values only slightly increased before resolution of rigor mortis. However, the K-values did not exceed 40% for 4 days post-resolution of rigor mortis. Differential Scanning Calorimetry analysis and tissue sectioning showed that protein denaturation and separation between muscle fibers persisted during storage at various temperatures, most notably at 25°C. It is important to note that storing at 0°C for 96 h did not result in any significant changes in the molecular protein composition. Moreover, the muscle tissue remained in excellent condition compared to storage at 25°C and 4°C. Additionally, there was no significant difference in the total viable count (TVC) and psychrophilic bacteria between storage at 0°C and 4°C, considered safe for food consumption. These promising findings are conveyed in a circular economy based on the food industry, particularly adequate raw materials, stable prices, measures to reduce food loss and waste, and contributing to developing efficient, diverse, and sustainable food processing systems.

Combined Treatment of Acidic Electrolyzed Water and High-Voltage Electrostatic Field Improves the Storage Quality of Huping Jujube (Ziziphus jujuba Mill. cv. Huping).

Fresh jujube is prone to rapid deterioration after harvest due to its active metabolism and rich nutrients. This study aimed to investigate the effects of acidic electrolyzed water (AEW), a high-voltage electrostatic field (HVEF) and a combination of AEW and HVEF (AEW + HVEF) treatments on the storage quality of Huping jujube (Ziziphus jujuba Mill. cv. Huping) stored at 0 ± 1 °C for 90 days. The results showed that the fruits treated with AEW + HVEF exhibited better storage quality than those treated with either AEW or HVEF alone. Specifically, the fruits treated with AEW + HVEF maintained higher levels of nutrients and taste compounds, including total soluble solid (TSS), total soluble sugar, reducing sugar and titratable acidity (TA), as well as lower respiration rate, weight loss, decay index and TSS/TA ratio. Additionally, the AEW + HVEF treatment could delay the increase in reddening index, a* and color change (ΔE) values, and the decrease in L* and b* values, by retarding the degradation of chlorophyll and accumulation of carotenoids and flavonoids, thereby preserving the more desirable appearance color. Furthermore, the combined treatment could enhance the glutathione reductase (GR) activity and 2,2'-azino-bis-(3-ethylbenzothizoline)-6-sulfonic acid (ABTS) +-scavenging ability. Thus, the AEW + HVEF treatment is a potential method for Huping jujube preservation.

Bioelectret poly(lactic acid) membranes with simultaneously enhanced physical interception and electrostatic adsorption of airborne PM0.3

Traditional polymeric fibrous membranes have been extensively used to reduce the health risks caused by airborne particulate matter (PM), leading to the dramatically increasing pollution of plastics and microplastics. Although great efforts have been made to develop poly(lactic acid) (PLA)-based membrane filters, they are frequently dwarfed by their relatively poor electret properties and electrostatic adsorptive mechanisms. To resolve this dilemma, a bioelectret approach was proposed in this work, strategically involving the bioinspired adhesion of dielectric hydroxyapatite nanowhiskers as a biodegradable electret to promote the polarization properties of PLA microfibrous membranes. In addition to significant improvements in tensile properties, the incorporation of hydroxyapatite bioelectret (HABE) enabled remarkable increase in the removal efficiencies of ultrafine PM0.3 in a high-voltage electrostatic field (10 and 25 kV). This was exemplified by the largely increased filtering performance (69.75%, 23.1 Pa) for PLA membranes loaded with 10 wt% HABE at the normal airflow rate (32 L/min) compared to the pristine PLA counterpart (32.89%, 7.2 Pa). Although the filtration efficiency of PM0.3 for the counterpart dramatically decreased to 21.6% at 85 L/min, the increment was maintained at nearly 196% for the bioelectret PLA, while an ultralow pressure drop (74.5 Pa) and high humidity resistance (RH 80%) were achieved. The unusual property combination were ascribed to the HABE-enabled realization of multiple filtration mechanisms, including the simultaneous enhancement of physical interception and electrostatic adsorption. The significant filtration applications, unattainable with conventional electret membranes, demonstrate the bioelectret PLA as a promising biodegradable platform that allows high filtration properties and humidity resistance.

Effect of high-voltage electrostatic field-assisted freeze-thaw pretreatment on the microwave freeze drying process of hawthorn

High-voltage electrostatic field assisted freezing (HVEF) and freeze-thaw (H-FT) pretreatment were conducted before the microwave freeze drying to improve the quality of freeze-dried hawthorn. The hawthorn samples were frozen at electric field intensities of 0, 1, 3, and 5 kV/cm (C, HVEF1, HVEF3, and HVEF5, respectively), and freeze-thawed in one to three cycles (H-FT1, H-FT2, and H-FT3, respectively) under the selected electric field intensity of 3 kV/cm. The control group was freeze-thawed in two cycles and without electric field treatment (CFT2). The results showed that the drying time of HVEF- and H-FT-treated hawthorn was reduced by 8–25% compared with that of the untreated hawthorn. The HVEF and H-FT pretreatments also affected the quality of hawthorn. Among the samples treated with HVEF, the total phenolic content of HVEF3 samples was the highest (46.31 mg GAE/g), followed by that of HVEF5 (41.87 mg GAE/g) and HVEF1 (37.25 mg GAE/g) samples. Similarly, among the samples treated with H-FT, the total anthocyanin content of H-FT2 samples was the highest (1.50 mg C-3-G eqiv/g), followed by that of H-FT1 (1.34 mg C-3-G eqiv/g) and H-FT3 (0.87 mg C-3-G eqiv/g) samples. Additionally, the H-FT2 treatment led to higher hardness (16.60 N), rehydration capacity (3.47 g/g), and total phenolic content (38.19 mg GAE/g) than the CFT2 treatment. In conclusion, H-FT2 improved the quality of hawthorn. This study lays a foundation for producing high-quality dried hawthorn using H-FT pretreatment, reducing the drying time and thereby improving drying efficiency.

Changes in water holding capacity of chilled fresh pork in controlled freezing-point storage assisted by different modes of electrostatic field action

Electrostatic field-assisted low-temperature preservation is considered a novel technology, which provides an effective means of extending the shelf-life of meat. This study aimed to investigate the effects of different output time modes of a high voltage electrostatic field (HVEF) on the water holding capacity (WHC) of chilled fresh pork during controlled freezing-point storage. Under a direct current HVEF generator, chilled fresh pork samples were treated by the single, interval, or continuous HVEF treatment, with a control check group receiving no HVEF treatment. It was determined that the WHC of the continuous HVEF treatment higher than the control check group. This difference was proven by analyzing the moisture content, storage loss, centrifugal loss, cooking loss, and nuclear magnetic resonance imaging. Furthermore, the mechanism behind HVEF-assisted controlled freezing-point storage reduced the moisture loss was conducted by examining the changes in the hydration characteristics of myofibrillar protein. The study revealed that myofibrillar proteins exhibit high solubility and low surface hydrophobicity under continuous HVEF. Additionally, continuous HVEF has been demonstrated to effectively maintain the higher WHC and lower hardness of myofibrillar protein gel by inhibiting the water molecule migration. The demonstration of these results showcases the effectiveness of electrostatic fields for the future physical preservation of meat.

The effect of high-voltage electrostatic field on the interactions between duck myofibrillar protein and inulin: An underlying mechanisms study

This study investigated the effect of high-voltage electrostatic field (HVEF) treatment on the interactions between duck myofibrillar protein (MP) and inulin, as well as explored the gel properties of adding inulin to duck MP. Hence, different inulin content (0–30 mg mL−1) were added to duck MP and HVEF treatment was applied in the gelation process.The results revealed that HVEF combined with the addition of 30 mg mL−1 inulin treatment significantly increased (P < 0.05) the water holding capacity and gel strength by 0.20 and 2.61 times, respectively. Moreover, the rheological characteristics and the formation of the three-dimensional network structure was promoted after added inulin and applied HVEF treatment. The HVEF treatment in modifying MP-inulin interaction promoted the conversion of α-helix to β-sheet, β-turn and random coil, significantly increased (P < 0.05) the content of R–SH groups and surface hydrophobicity, thus revealing the underlying mechanisms of the enhancement of duck MP gel performance. Principal component analysis revealed these interrelationships. This data demonstrated that inulin addition combined with HVEF treatment might be a new and effective strategy to enhance the duck MP gel properties.

Preparation of sodium-containing coacervates via high-voltage electrostatic field treatment: Saltiness perception of prefabricated chicken patties

Sodium-containing soy protein isolates (SPI)/apple pectin (AP) coacervate dispersion were prepared via high-voltage electrostatic field (HVEF) application to inhomogeneous spatial distribution of sodium as a strategy for reduction of salt content and enhancing the saltiness of prefabricated chicken patties. SPI/AP coacervates were prepared by HVEF processing at pH of 4.0, HVEF voltage of 32 kV, and ratio of SPI: AP to 5:1 which was optimized according to Artificial neural network (ANN)-coupled with genetic algorithm. Fluorescence intensity and FTIR analysis demonstrated that the HVEF treatment caused alteration of protein conformation, improved hydrogen bonding and electrostatic interactions between SPI and AP. At the NaCl concentration of 100 mM, HVEF treated sodium-containing SPI/AP coacervates achieved maximum phase separation as well as coacervate yield (85.23 ± 0.51%). HVEF treated sodium-containing SPI/AP coacervates displayed increased sodium fluorescence intensities, higher sodium concentration difference between coacervate phase and supernatant, and smaller particle sizes. Furthermore, HVEF treated coacervate dispersion showed higher sodium release in vitro during oral digestion. The saltiness of prefabricated chicken patties prepared using HVEF treated coacervates dispersion allowed a reduction in the sodium content of 43.59%. The increase of saltiness perception and sodium release in prefabricated chicken patties is attributed to enhanced water mobility in the matrix and distribution of inhomogeneous sodium.

High-Voltage Electrostatic Fields Adversely Affect the Performance of Diamondback Moths over Five Consecutive Generations

Changing electrical environments can influence the performance of herbivorous insects and adversely affect their control strategies. The diamondback moth, Plutella xylostella (L.), is a pest that devastates cruciferous vegetables. An age–stage, two-sex life table of P. xylostella over multiple generations was established to describe the effect of varying high-voltage electrostatic field (HVEF) exposure on their performance after the age-cohort eggs were exposed to HVEF at an intensity of 5.0 kV/cm for different durations. The results show that direct HVEF exposure adversely affected the population dynamics parameters of P. xylostella over multiple generations. In particular, the net reproduction rate, intrinsic natural increase rate, and finite increase rate of the P. xylostella population significantly decreased in the third and fifth generations under HVEF exposure for 10 min, while the mean generation time and doubling time significantly increased. Similarly, HVEF exposure for 10 min rapidly reduced the survival rate of adult P. xylostella in the first generation, and subsequently, it declined evenly and slowly. Meanwhile, the fecundity parameters of P. xylostella revealed that HVEF exposure for 10 min had the strongest inhibition effect on reproduction over five consecutive generations. In addition, HVEF exposure significantly increased the superoxide dismutase activity to produce extra hydrogen peroxide; however, increased catalase and peroxidase activity or reduced peroxidase activity triggered the accumulation of malondialdehyde in instar P. xylostella, especially after 10 min of treatment. The present findings provide experimental evidence and a theoretical basis for developing control strategies for P. xylostella under new HVEF environments.

Experimental study on electrostatic atomization effect of capillary-plate electrode

The electrostatic atomization effect of liquid in high voltage electrostatic field was studied under capillary-flat electrodes. The effects of charging voltage, liquid flow rate, and the distance between a capillary and flat electrode on droplet size distribution were analyzed by the DP-02 laser particle size analyzer. The single-factor method was used to analyze the effects. The experimental results show that the charging voltage, the liquid flow rate, and the distance between the capillary and the plate electrode greatly influence the droplet's atomization effect. The median particle size D50 and the distribution span (Span) decrease with the increase of charging voltage, the reduction of liquid flow and the decline of the distance between capillary and plate electrode. That is, the droplet particle size distribution is better, and thus the droplet electrostatic atomization effect is better.

Postharvest storage properties and quality kinetic models of cherry tomatoes treated by high-voltage electrostatic fields

High-voltage electrostatic field (HVEF) is an emerging environment-friendly technology and has great application prospects as a new preservation method for storing fruits and vegetables. Effects of HVEF treatment time on the quality characteristics of cherry tomatoes during storage were determined. The cherry tomatoes were treated continuously for different lengths of time (0, 30, 60, 90, and 120 min) with an electric field strength of 150 kV/m. Multiple physicochemical and microbial indices of treated samples during storage were detected. Finally, the kinetic models of quality indices with storage time were established. The results showed that compared with the control group, the weight loss and the color change of cherry tomatoes treated by HVEF decreased by 8.48%–23.00%, and 25.08%–58.57%, respectively. HVEF treatment resulted in higher hardness and Vitamin C content, stronger antioxidant capacity, lower microbial loads and microstructure. The zero-order reaction model had a good fit to the changes in most physicochemical indices of cherry tomatoes treated with HVEF. The modified Gompertz equation better described the growth curve of microorganisms in treated cherry tomatoes. These findings may provide a basis in establishing a shelf-life prediction model for cherry tomatoes.

Effects of high-voltage electrostatic field (HVEF) on frozen shrimp (Solenocera melantho) based on UPLC-MS untargeted metabolism

Shrimp meat is prone to autolysis and decay due to the abundance of endogenous enzymes and contamination from microorganisms. HVEF freezing can slow the spoilage of shrimp, producing small and uniform ice crystals, resulting in less damage to muscle tissue. In this study, HVEF technique was used to freeze the shrimp (Solenocera melantho), and the UPLC-MS metabolic technique was used to investigate the metabolites of frozen shrimp meat. Compared with the control group, 367 differential metabolites were identified in the HVEF group. Mapping them to the KEGG database, there were 108 with KEGG ID. Purine metabolism and pyrimidine metabolism were the most enriched pathways. In addition, phosphatidylcholines (PCs), inosine (HxR), and l-valine were identified as potential biomarkers associated with lipid, nucleotide, and organic acid metabolism, respectively. Overall, HVEF can improve freezing quality of shrimp meat by slowing down the metabolism of substances in the muscle of S. melantho.

The effects of freezing under a high-voltage electrostatic field on ice crystals formation, physicochemical indices, and bacterial communities of shrimp (Solenocera melantho)

A high-voltage electrostatic field (HVEF) can affect the formation of ice crystals and improve food quality by inhibiting the growth of some bacteria. In this study, different intensities of HVEF were used to assist in the shrimp ( Solenocera melantho ) freezing process, and the effects of the HVEF were explored using the ice crystal structure, physicochemical indexes, and bacterial communities. The results showed that the HVEF effectively improved the freezing quality of S. melantho . The freezing speed was improved, especially in the zone of maximum crystallization. Small and uniform ice crystals were generated at 15 kV/m and 20 kV/m. The texture of the shrimp muscle improved, and the degeneration of myofibrillar protein isolates decreased. Blackening of the shrimp head and polyphenol oxidase activity were inhibited. High-throughput sequencing analysis showed that the bacterial community structure changed significantly at 15 and 20 kV/m, which was lower than that in the other groups. The HVEF exerted an inhibitory effect on most bacteria, and this effect was related to the intensity of the HVEF. Based on these results and energy consumption considerations, the HVEF at 15 kV/m is more suitable for the auxiliary freezing of S. melantho . • High-voltage electrostatic field (HVEF) was used to treat the S. melantho. • The optimal electric field intensity of HVEF on freezing S. melantho was determined. • Ice crystal structure was investigated to study the change of freezing quality of S. melantho. • The effects of HVEF on the bacterial communities of S. melantho were studied by 16S rRNA.

Physicochemical and Functional Properties Changes in Myofibrillar Protein Extracted from Channel Catfish by a High-Voltage Electrostatic Field

Physicochemical and Functional Properties Changes in Myofibrillar Protein Extracted from Channel Catfish by a High-Voltage Electrostatic Field

A Review on Current Nanofiber Technologies: Electrospinning, Centrifugal Spinning, and Electro‐Centrifugal Spinning

AbstractNanofiber‐based products are widely used in the fields of public health, air/water filtration, energy storage, etc. The demand for nonwoven products is rapidly increasing especially after COVID‐19 pandemic. Electrospinning is the most popular technology to produce nanofiber‐based products from various kinds of materials in bench and commercial scales. While centrifugal spinning and electro‐centrifugal spinning are considered to be the other two well‐known technologies to fabricate nanofibers. However, their developments are restricted mainly due to the unnormalized spinning devices and spinning principles. High solution concentration and high production efficiency are the two main strengths of centrifugal spinning, but beaded fibers can be formed easily due to air perturbation or device vibration. Electro‐centrifugal spinning is formed by introducing a high voltage electrostatic field into the centrifugal spinning system, which suppresses the formation of beaded fibers and results in producing elegant nanofibers. It is believed that electrospinning can be replaced by electro‐centrifugal spinning in some specific application areas. This article gives an overview on the existing devices and the crucial processing parameters of these nanofiber technologies, also constructive suggestions are proposed to facilitate the development of centrifugal and electro‐centrifugal spinning.

Effects of HVEF treatment on the physicochemical properties and bacterial communities of Larimichthys crocea fillets during refrigerated storage

SummaryThis study investigated the effects of a high voltage electrostatic field (HVEF) on the physicochemical properties and bacterial communities of Larimichthys crocea (L. crocea) fillets. HVEF‐treated samples (5, 10 and 15 kV/m) and control samples (0 kV/m) were stored at −1 ± 0.5 °C for 0, 4, 8, 12, 16, 20 and 24 days. Compared with the control group, the HVEF‐treated groups (10 and 15 kV/m) had less muscle fibre damage and better tissue structures. In addition, HVEF treatment delayed the decrease in springiness and hardness, improved the quality of fish during refrigerated storage and effectively extended the shelf‐life of L. crocea fillets. The HVEF‐treated groups had a considerably lower total viable count (TVC) than the control group. Furthermore, high‐throughput sequencing revealed that HVEF treatment reduced the relative abundance of Shewanella by 21.48% at 8th day, implying that spoilage bacteria growth was inhibited. The results indicated that HVEF treatment could be used as a new technology in the fish processing industry to delay L. crocea fillet deterioration.