Page 31 - FoodFocusThailand No.226 January 2025

SPECIAL
SPECIAL FOCUS FOCUS

Magnetic Field Processing:

A New Alternative for the Food Industry

Magnetic field processing (MF) offers an innovative solution for enhancing food properties and quality,
including extended shelf life, through microbial neutralization, freezing acceleration, and improved water
quality for food production.

Limitations of Modern Food Processing density, or magnetic field density, is measured in Wb/m² or Tesla
Technologies (T) and is categorized into low (<1 mT), medium (1 mT–1 T),
Contemporary food processing technologies like ultrasound high (1–5 T), and very high (>5 T). In terms of frequency, it can
(US), high-pressure processing (HPP), radio frequency (RF), be divided into low frequency (<300 Hz), medium frequency (300
and high-voltage electrostatic fields (HVEF) are effective at Hz–10 MHz), and radio frequency (10 MHz–300 GHz). Key
preserving food and beverages by inhibiting bacterial growth density parameters include strength, magnetic permeability,
and enzymatic activity while promoting plant and seed growth. magnetic flux, and magnetization, with MF density being the most
However, they face notable limitations: US has limited critical factor in food processing applications.
penetration and risk of thermal buildup; HPP is potentially
marked by high costs and potential protein structure or color Mechanism of Magnetic Field in
changes; RF requires full equipment insulation; and HVEF Microbial Control
may pose safety risks due to high electric potential Barbosa-Cánovas et al. report that PMF, when applied at an
1
differences. intensity of 5–50 T, with 1–100 pulses, a frequency of 5–500 Hz,
a temperature range of 0–50 °C, and an exposure time of 25–100
Magnetic Field Processing: µs, can reduce microbial growth by 2 log (CFU). SMF has been
Enhancing Food Quality and Shelf Life shown to generate free radicals that damage the cell membranes
Magnetic field processing addresses these limitations by being of E. coli, while PMF can alter protein stability within Listeria.
non-thermal, ensuring minimal temperature increase even at Additionally, OMF has been found to affect enzyme activity in S.
high magnetic field intensities. Research demonstrates that cerevisiae, inhibiting yeast cell growth and potentially killing some
MF is a safe and convenient method, leaving no residues or cells. However, the surviving yeast cells may exhibit increased
unwanted chemicals. It inhibits microbial growth, enhances intracellular activity, influenced by the movement of ions such as
fermentation, and regulates enzymatic activity in applications K , Ca² , and Mg² , or by applying electric fields associated with
+
+
+
like chilling, freezing, supercooling, and drying. Ideal for meat, the Lorentz force, which can alter the permeability of cell walls
vegetables, and fruits, it also aids in dissolution, extraction, and membranes. 2
and protein modification. Moreover, MF integrates seamlessly While still in development, MF processing holds immense
with other technologies such as US, pulsed electric fields promise for the food industry. Leaving food quality intact, its ability
(PEF), and functional materials, optimizing food manufacturing to preserve nutrients, reduce additives, and complement other
processes. technologies makes it a sustainable and efficient solution to
MF is based on the principle of altering the direction and evolving food processing challenges.
intensity of the magnetic field over time. The main types of MF
include static magnetic field (SMF), rotating magnetic field
(RMF), alternating magnetic field (AMF), pulsed magnetic field
(PMF), and oscillating magnetic field (OMF). Magnetic flux More Information Service Info C004

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