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This study aimed to explore the effect of induced electric field (IEF) treatment on acid hydrolysis of corn starch by altering the connection modes of sample coils of a 4-reactor IEF system. Results suggested that IEF treatment could enhance the hydrolysis of corn starch and series connection (1. RRRR, η = 16 E Si 2 P in 4 Z Si + Z load ) exhibited higher energy efficiency than parallel (9. (RRRR), η = 4 E Si 2 P in Z Si + 4 Z load ), thus contributing to more extensive hydrolysis. Although no new functional group was formed, the starch granules were partially cracked into pieces and the crystallinity was slightly increased after IEF-assisted hydrolysis. Differential scanning calorimetry results indicated that IEF-assisted hydrolysis increased the gelatinization temperatures but decreased the enthalpy of starch, with a greatest variation was observed by series connection. Rapid visco-analysis showed that IEF-assisted hydrolysis greatly decreased the pasting viscosity of corn starch and also series connection showed the strongest reduction. The obtained results could provide a theoretical guide for the applications of IEF technology in biomaterial processing. [Display omitted] • Induced electric field (IEF) could enhance the acid hydrolysis of corn starch. • IEF-assisted hydrolysis highly depends on the energy efficiency of IEF system. • Series connection of IEF reactors showed the highest energy efficiency. • IEF-assisted hydrolysis largely decreased the pasting viscosity of corn starch. • IEF-assisted hydrolysis increased gelatinization temperatures but decreased enthalpy. [ABSTRACT FROM AUTHOR]

A disposable continuous-flow system was established by treating apple juice with induced electric field (IEF). Under synchronous alternating magnetic flux, rather than electrodes, the electrical treatment was implemented in multi-series coils consisting of the flowing sample. An activation effect at 50 °C and inactivation effect at 70 °C were observed under IEF. High excitation voltage (900 V) caused a significant decrease in the residual activities (RA). As the flow rate decreased from 87.5 to 17.5 mL/min, RA of PPO and POD were changed without applying IEF indicated shear effect of the pump had an impact on the RAs. At 17.5 mL/min, PPO was inactivated after IEF treatment for 7.6 min. In compared with the control (0 V), the fluid impedance was increased at 70 °C and 80 °C under IEF, whereas it was decreased at 30 °C and 40 °C. IEF had no adverse influence on the color and volatile compounds of apple juice in this system. [ABSTRACT FROM AUTHOR]

Compared to traditional heating methods by static immersion or stirring, induced electric field (IEF) treatment can significantly increase hydrolysis rate of potato starch. The aim of this study was to examine the characterization of acid hydrolysis of granular potato starch under IEF. Potato starch was hydrolyzed using 0.15 mol/L HCl combined with IEF (IEF-HCl) at an excitation voltage of 75 V from 4 h to 120 h. The changes in granular, crystal, and molecular structure of starch granules during IEF-HCl hydrolysis were investigated. Scanning electron microscope analysis showed the outer surface of potato starch was firstly attacked by free ions and then the inner structures was completely disrupted and broken into pieces. X-ray diffraction studies indicated that the crystallinity decreased from 38.92% to 34.9% after 4-h hydrolysis, and then gradually increased to 41.88% as hydrolysis time increased to 96 h, but decreased thereafter. The weight-average molecular weight dramatically decreased from 104.7 × 10 6 Da to 9.291 × 10 6 Da in the first 24 h and then decreased gradually. These results suggested that there were three steps in the catalytic process of IEF-HCl hydrolysis. Initially, hydrogen ions destroyed the external crystalline shell of granules. Next, hydrogen ions attacked the loose amorphous region and dense crystalline part within starch granules simultaneously. Finally, the remaining crystalline region was hydrolyzed slowly. [ABSTRACT FROM AUTHOR]

The induced electric field assisted hydrochloric acid (IEF-HCl) hydrolysis of potato starch was investigated in a fluidic system. The impact of various reaction parameters on the hydrolysis rate, including reactor number (1–4), salt type (KCl, MgCl 2 , FeCl 3 ), salt concentration (3–12%), temperature (40–55 °C), and hydrolysis time (0–60 h), were comprehensively assessed. Under optimal conditions, the maximum reducing sugar content in the hydrolysates was 10.59 g/L. X-ray diffraction suggested that the crystallinity of IEF-HCl-modified starches increased with the intensification of hydrolysis but was lower than that of native starch. Scanning electron microscopy indicated that the surface and interior regions of starch granules were disrupted by the hydrolysis. The solubility of IEF-HCl-modified starches increased compared to native starch while their swelling power decreased, contributing to a decline in paste viscosity. These results suggest that IEF is a notable potential electrotechnology to conventional hydrolysis under mild conditions without any electrode touching the subject. [ABSTRACT FROM AUTHOR]

Creating a fluidic system with an induced electrical field is regarded as an innovative, eco-friendly practice for the hydrolysis of lignocellulosic biomass at mild conditions. A multi-series, reconfigurable fluidic reactor was developed based on the transformer concept for the efficient hydrolysis of sugarcane bagasse via the interconversion of magnetic and electrical energy. A secondary coil comprised of a mixture of sulfuric acid (or other metal electrolyte) and the sample in continuous flow was exposed to an induced electric field at 400–700 Hz to accelerate the hydrolysis. The results showed that using an induced electric field to assist hydrolysis is indeed beneficial in the production of reducing sugar (RS). The total reducing sugar (TRS) yield is positively impacted by the excitation voltage but is negatively impacted by voltage frequency and the sample solution impedance. The hydrolysis efficiency improves as the number of reactors increases in both series and parallel modes of the system. The mode of connection of the reactors has varying effect on the TRS yield owing to differences in the equivalent impedance, output power, and load power factor. Increased number of secondary coil turns also improves hydrolysis efficiency under the same input power and primary coil turns and thus increasing the TRS yield. Induced-electric-field-assisted hydrolysis (IEFAH) substantially enhances the yield (by 756% approximately, at 300 V, 400 Hz in a 4-series reactors for 24 h) compared to continuous flow heating hydrolysis (CFHH) at mild conditions (50 °C and 1% H 2 SO 4 ). The proposed fluidic system combined with an induced electric field shows remarkable potential as a green technology for the efficient hydrolysis of lignocellulosic biomasses without the use of metal electrodes. [ABSTRACT FROM AUTHOR]

A multi-series fluidic system based on the transformer concept was designed and built for the induced-electric-field-assisted extraction (IEFAE) of mulberry leaves polysaccharides (MLPs). Extraction was accelerated by exposing a secondary coil, made from a flowing mixture of sample grains and extractant, to a 20–80 kHz induced alternating electric field. The results indicate that this method benefits the release of polysaccharides without significantly affecting the quality of the products as evidenced by carbohydrate, protein, uronic acid, sulfuric radical and total polyphenol contents as well as average molecular weights and FT-IR . The polysaccharide yield improved as the excitation voltage increased, but the voltage frequency had a negative impact on the yield. At a solid-liquid ratio of 1:20 (g/mL), pH of 2.5, 60 °C temperature, 1000 V excitation voltage, and 20 kHz frequency, the 16-series system is performed optimally with a yield increased by 225.95% compared to the control (0 V). The relatively low environmental pH is conducive to extraction under the electric field, making the proposed system efficient for the extraction of valuable compounds without using metal electrode. [ABSTRACT FROM AUTHOR]

The effects of induced electric field (IEF) on the crystal structure and physicochemical properties of potato starch were investigated by subjecting identically treated control and electrically-modified samples to the same temperature history. Additionally, a method of combining IEF with heating for efficient modification of native polymer was also proposed. Results showed that the application of IEF at an electric voltage of 75 V has a statistically significant effect on starch gelatinization and pasting properties, especially when combined with heating at 50 °C. After treatment by the combination method for 96 h, the gelatinization temperatures increased, which can be explained by the slight increase in the ratio of 1044/1015 cm −1 and relative crystallinity. Furthermore, IEF reduced granular swelling and therefore contributed to decreasing the peak, breakdown, and setback viscosity of potato starch. This study explores the potential of IEF as innovative technology for starch modification. [ABSTRACT FROM AUTHOR]

Using the mutual conversion between electric energy and magnetic energy, we designed and built an experimental device based on the o-core transformer structure for extraction of garlic polysaccharides. That is, an acidic solvent acted as the secondary coil conductor under the action of alternating magnetic flux and then induced an electric field in the biochemical medium (the sample and extractant) at 20-60 kHz. The polysaccharide yield improved, in comparison to the conventional heating method, when the excitation voltage applied on the primary coil was increased. Low pH helps to improve the polysaccharide yield due to the enhancement of the ionic conduction resulting from the induced electric field. However, the polysaccharide yield decreases with the increase of partial frequency due to the resulting decrease in the input power of the system. The orthogonal experiments showed that the excitation voltage, frequency, pH, and temperature all significantly affected the polysaccharide yield. The garlic polysaccharide extracted by using the induced electric field method had a DPPH radical scavenging ability and a ferric-reducing power. This novel system is a potential alternative for the extraction of garlic polysaccharides without the use of powered electrodes inserted into solutions, unlike other electric-field-assisted techniques. [ABSTRACT FROM AUTHOR]

An experimental system based on the o-core transformer structure was established and used to extract pectin from orange peel waste. Unlike other electric-field-assisted techniques, it avoids the use of powered electrodes. The acidic solvent acts as the secondary coil connected to a purpose-made glass chamber which forms a closed loop. Then the induced electric field in the system appears to be under the influence of alternating magnetic flux based on Faraday's law of induction . We found that an increase in the excitation voltage causes enhancement of the pectin yield. Increasing frequency from 20 to 200 kHz had a negative impact on pectin yield partially due to the increased impedance of the primary coil. The ionic conduction was enhanced at the same excitation voltage since there are more free ions in the mixture at lower pH. This means that a lower impedance in the mixture is conducive to extraction. This multidisciplinary technique combines the transformer concept with the electric-field-assisted process, thus providing a reference for the application into agricultural by-products treatment. [ABSTRACT FROM AUTHOR]

• A novel technique-Induced Electrical Field (IEF) for liquid sterilization was proposed. • The sterilization effects of IEF could be amplified with special structure. • The IEF treatment with moderate heat kept higher total phenol and reducing sugar. • A significant thermal effect and reduction of S. cerevisiae about 4.6 log (CFU/mL) were observed. The non-conventional technologies about continuous sterilization of liquid food were focused on recently, which is benefits for industrialization. In this study, the machine with an induced electric field was used to sterilize S. cerevisiae in apple juice and the juice quality also was researched. The optimal condition is 800 V, 400 Hz, 5 rpm and 2 mm. Furthermore, the sterilization of the IEF was attributed to non-thermal and thermal effects. The IEF treatment group has a reduction of about 4.6 logs (CFU/mL) in S. cerevisiae at 400 Hz, 800 V, and 2 mm, while the non-thermal group is nearly 2 logs (CFU/mL). The improvement of conductivity and the reduction of pH value imply that IEF might destroy the cell structure. Meanwhile, polyphenol compounds and amino acids in the IEF group were protected well than other groups. Generally, IEF is a potential technology for industrial sterilization of liquid beverages. [ABSTRACT FROM AUTHOR]

The novel, previous unreported induction heating technique developed here uses the inverse process of the existing induction heating techniques. The theoretical basis for developing this technique is to determine whether the induced current passing through a winding food coil would induce a magnetic flux or cause an increase in primary current. Therefore, to develop this technique and implement it in the food industry, it is necessary to understand its technical details and engineering characteristics. This study presents the design and development process of the technique, as well as the calculation formulas, including load voltage, induced electric field, induced current density, heating power and energy utilization rate during the heating process. The results reveal that although the application of this innovative inner heating technique has been achieved, the energy efficiency of the current system is low. The thermal effect and non-thermal effect of the induced electric field decreased the total bacterial counts in the samples of grapefruit juice and raw milk. Image 10083 • Innovative induction heating is a sister technology to ohmic heating in the food industry. • Liquid food can act as the secondary winding of a transformer for inner heating. • A thermal effect on liquid foods by an alternating magnetic field was observed. • The development and design process of this novel technique are presented. • Continuous-flow pasteurization of liquid food was achieved by an induced electric field. [ABSTRACT FROM AUTHOR]

This study aimed to improve induced electric field (IEF)-assisted hydrolysis of polysaccharide by controlling electrical conductivity. As the conductivity of reaction medium was increased, the energy efficiency of IEF was increased because of deceased impedance, as well as enhanced output voltage and temperature, thus the hydrolysis of guar gum (GG) was accelerated under IEF. Changes in weight-average molecular weight (Mw) suggested that IEF-assisted hydrolysis of GG could be described by the first-order kinetics 1/Mw ∝  k t, with the rate constant ( k ), varying directly with the medium conductivity. Although IEF-assisted hydrolysis largely disrupted the morphological structure of GG, it had no impact on the chemical structure. In comparison to native GG, the steady shear viscosity of hydrolyzed GG dramatically declined while the thermal stability slightly decreased. This study extended the knowledge of electrical conductivity upon IEF-assisted acid hydrolysis of GG and might contribute to a better utilization of IEF for polysaccharide modification. [ABSTRACT FROM AUTHOR]

In this study, the effectiveness for induced electric field-assisted alkali pretreatment (IEF-AAP) of wheat straw (WS) was evaluated and compared with hydrothermal assisted alkali pretreatment (HT-AAP). The influence of IEF-AAP and HT-AAP on enzymatic hydrolysis of WS based on physico-chemical changes were investigated. The maximum lignin and hemicellulose removal of residual WS after IEF-AAP were 78.9 % and 70.0 %, remarkably higher than that of HT-AAP (74.4 % and 60.6 %), which can be explained by the electrical effect. The optimized IEF-AAP conditions were alkali concentration 1.5 %, temperature 80 °C and duration 3 h. Under optimized conditions, the enzymatic efficiency of WS after IEF-AAP was 79.7 %, while that after HT-AAP was 74.9 %. The surface morphology, functional groups, porosity characteristics, crystallization as well as thermal stability of residual WS after IEF-AAP and HT-AAP were analyzed. It was found that electrothermal pretreatment had more pronounced effect on the physicochemical properties of WS, mainly manifested as complex morphological structure and pore properties. There was no obvious difference between the lignin prepared by the two processes. Induced electric field, as a novel electrotechnology, has shown potential in the pretreatment of lignocellulose. It also provides an idea for the development of new preprocessing strategies. [Display omitted] • Efficient delignification of WS by IEF-AAP is confirmed via magnetoelectric effect. • Lignin and hemicellulose removal of WS after IEF-AAP are 78.9 % and 70.0 %. • The enzymatic efficiency of WS after IEF-AAP is 79.7 % under optimal conditions. • There is no obvious difference between the lignin prepared by IEF-AAP and HT-AAP. [ABSTRACT FROM AUTHOR]

Non-conventional heating technology based on electric fields can be utilized to process liquid foods. In this study, the induced electric field (IEF) was investigated to clarify its inactivation mechanism on E.coli. Staining results show that inactivation of E.coli by IEF can be attributed to the reversible destruction of the cell membrane, followed by the denaturation of intracellular enzymes, and finally the irreversible rupture of the cell membrane. The increased levels of extracellular proteins and nucleic acids were also observed. IEF treatment at 400 Hz and 800 V (or 53 V/cm) results in a reduction of 4.5 log CFU·mL−1 in the number of E.coli. Storage life analysis shows that IEF treatment can improve the stability of apple juice and the content of bioactive components. Thus, IEF is a potential technique for liquid food processing. • The inactivation mechanism of induced electric field on E.coli was investigated. • A reduction of 4.5 log CFU·mL−1 of E.coli was realized by applying the IEF. • IEF treatment retains bio-active components in fresh apple juice. • The storage stability of apple juice was improved through IEF treatment. [ABSTRACT FROM AUTHOR]

This study evaluated the effectiveness of induced electric field (IEF) as a novel electrotechnology to assist dilute acid pretreatment of wheat straw (WS) at atmospheric pressure and low temperature (90 °C). The effects of acid concentration and duration on cellulose recovery, hemicellulose and lignin removal were investigated. Meanwhile, the differences between IEF pretreatment and hydrothermal pretreatment were compared by quantitative and qualitative analysis. The optimal pretreatment condition was acid concentration 1 % with the period of 5 h. Under the parameters, the hemicellulose removal of WS after IEF pretreatment was up to 73.6 %, and the enzymatic efficiency was 55.8 %. In addition, the irregular surface morphology, diminished functional groups associated with hemicellulose, increased specific surface area and pore volume, as well as improved thermal stability of the residual WS support the remarkable effect of IEF pretreatment. The feasibility of IEF pretreatment is might be due to the fact that the magneto-induced electric field promotes ionization of H + and formation of hydrated hydrogen ions, increasing the acidity of the medium. Secondly, electroporation disrupts the anti-degradation structure of WS and increases the accessibility of cellulose to cellulases. It indicated that IEF is a green and efficient strategy for assisting the separation of hemicellulose from lignocellulose. [Display omitted] • Effectiveness of IEF-DAP for WS at low temperature was evaluated. • The hemicellulose removal of WS after IEF-DAP was up to 73.6 %. • IEF-DAP was more effective than HT-DAP in improving enzymatic efficiency. • IEF may act by promoting ionization, ion migration, and electroporation. [ABSTRACT FROM AUTHOR]

• IEF-assisted hydrolysis enhanced with increasing DD of chitosan. • Electrical properties of chitosan showed no significant effect on the hydrolysis. • Structural compactness determined the hydrolysis behavior of different-DD chitosan. This study explored the impact of re-acetylation on induced electric field (IEF)-assisted hydrolysis of chitosan. Chitosan with different degree of deacetylation (DD) exhibited different charge content but similar electrical conductivity and output voltage of the electrolyte system, thus theoretically resulting in equivalent electro-processing efficiency. However, molecular and rheological measurements suggested that the hydrolysis rate decreased with an increase of DD. Re-acetylation had no significant effect on the molecular weight and viscosity of chitosan but damaged its granular and crystal structure, making chitosan chains more susceptible to the acid. The IEF-assisted hydrolysis of dissolved chitosan confirmed that the structural compactness of chitosan played a more important role on the hydrolysis than the charge content. This study extended current knowledge regarding the effect of charge content and structural compactness on IEF-assisted hydrolysis process, which contributed to the applications of IEF in biopolymer modification. [ABSTRACT FROM AUTHOR]