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The induced electric field (IEF) was produced via an oscillating magnetic field, for direct heating of orange juice within a winding coil. During the process, the applied magnetic field was at the range from 0.07 to 1.43 T with 50 kHz. Then, the numerical relationships between excitation voltage, magnetic field, IEF, induced current density, magnetomotive force and energy efficiency were investigated. Since a rectangular wave of excitation voltage was applied, the sawtooth waveform of induced voltage or IEF loaded on the juice was observed. As the magnetic field increased, outlet temperature and induced current density in the juice was improved, the maximum values were 99.5°C and 0.50 A/cm2, respectively, at a conductivity 4.53 mS/cm for the residence time of 4.5 min. However, the efficiency of the process exhibited a negative correlation with the escalation of excitation voltage. At initial colony count about 4.50 log colony‐forming units/mL, the IEF pasteurization reduced all the aerobic microorganisms, molds, and yeasts in the juice, which were evaluated at detectable limits below 1 log colony‐forming units/mL. Moreover, all treatments had no significant effects on pH, total soluble solids and titratable acidity of the juice (p > 0.05). In particular, there was also no significant change in color parameters after IEF pasteurization (p > 0.05). It indicated a significant decrease in vitamin C and total phenolic content of the control groups (p > 0.05), but no significant change in carotenoid content was observed in all treated juice (p > 0.05). heating technology using IEF has the potential to the pasteurization of fruit juice. Practical applications: Induction electric field technology has progressed rapidly in the past 2 years, it can use oscillating alternating magnetic field to realize the direct heating of liquid food. The process has thermal and non‐thermal effects, at 65–70°C, within 15–30 s to achieve the commercial asepsis of acidic liquid food. After the pasteurization, it can better maintain the color and flavor of the juice. We have assembled a laboratory prototype for testing in the early stage, the processing capacity is at the range of 0–10 L/h. Currently, the system has been able to reach the pilot production scale with the processing capacity of 100–500 L/h. Through the use of highly permeable magnetic materials, the energy consumption per ton of juice processing is controlled at 120 k·Wh level for the pasteurization and is expected to achieve a larger processing capacity in the future. [ABSTRACT FROM AUTHOR]

A continuant-flow induced electric field (IEF) apparatus was presented for the treatment of the milk. The electric field originated from the magnetic energy, and the volumetric heating of the milk was observed. The inactivation effect of IEF treatment on the milk inoculated with exogenous bacteria was investigated under different IEF strengths (11.11, 14.81 and 18.52 V/cm) and the duration (98, 131 and 196 s), IEF treatment reduced E. coli and S. aureus by more than 5.9 Log CFU/mL, and the damage to cell membrane caused by the non-thermal effects was observed via SEM images. Under 14.81 V/cm for 196 s, the total number of colonies in raw milk was reduced by 4.58 Log CFU/mL. The results demonstrated IEF treatment effectively preserved nutritional properties of milk, with no significant influence on protein content. Furthermore, IEF-treated milk exhibited smaller color changes, compared to conventional heat (CH) treatments, while the process did not lead to the accumulation of casein and milk fat globules. Because of rapid temperature rise and electroporation effect on microorganisms, it suggests that IEF treatment has the potential to dairy processing. • The volumetric heating of the milk was observed via induced electric field. • IEF treatment reduced E. coli and Staphylococcus aureus by more than 5.9 Log. • IEF treatment had minimal effect on physicochemical properties of the milk. • Significant cytoarchitectural damage was observed by SEM. [ABSTRACT FROM AUTHOR]

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]

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]