Page 47 - FoodFocusThailand No.230 May 2025

SMART PRODUCTION

Plasma, often referred to as ‘the fourth state of treatment, in which plasma is first generated in a medium before
matter’, is an ionized gas composed of reactive use. A common example is plasma-activated water (PAW), where
species, free electrons, ions, and neutral particles. It water is exposed to cold plasma to generate reactive species
is generated by applying electrical energy—such as that can then be used for various applications. These include
high voltage, radio frequency (RF), or microwave washing fresh produce to reduce microbial contamination and
energy—to a gas (commonly air, oxygen, nitrogen, pesticide residues, as well as cleaning food-contact surfaces,
argon, or a gas mixture). This energy excites the gas equipment, and packaging materials.
molecules, causing the outer electrons to be removed Many modern food processing technologies are already in
from atoms or molecules—a process known as use. However, changes in the economy, society, environment,
ionization—which leads to the formation of plasma. and consumer behavior continue to drive the development of
new technologies that support long-term food safety and
Mechanism of Action of Cold Plasma sustainability. Over the past decade, cold plasma technology
Technology has been extensively studied, including its effects on the chemical
Common cold plasma generation methods include composition of food, physical properties, food quality and safety,
atmospheric pressure plasma jet (APPJ), dielectric shelf-life extension, scaling up for industrial applications, and
barrier discharge (DBD), corona discharge, and radio even clinical studies. These efforts reflect the continuous
frequency discharge. The ionized gas produces advancement of technology and the formation of an ecosystem
reactive oxygen species (ROS) and reactive nitrogen that supports its practical application across the food industry,
species (RNS), such as hydrogen peroxide (H O ), academic institutions, and among consumers. Such integrated
2
2
superoxide (O ), hydroxyl radical (•OH), and nitric development is essential to propel the food industry forward
-
2
oxide (NO). These highly reactive species can toward a more sustainable and resilient future.
damage the microbial cell membrane through
oxidative stress, which occurs when there is an
imbalance between the generation and removal of
free radicals inside and outside the microbial cell. More Information Service Info C005
This leads to damage to the cell membrane, proteins,
lipids, and carbohydrates, resulting in microbial
inactivation or degradation. Additionally, cold plasma
generates UV radiation and electric fields, which can
damage microbial DNA and RNA, ultimately causing
cell death.
Besides microbial safety, cold plasma also
contributes to chemical safety. It can reduce chemical
residues, such as pesticides and mycotoxins, on fruits
and vegetables. This is achieved by the action of
plasma-generated reactive species that break down
the structure of pesticides, especially organophosphate
and carbamate, resulting in less toxicity. Moreover,
cold plasma can be applied in a variety of food
processing applications, including the improvement
of physical and chemical properties of animal- and
plant-based protein products, surface decontamination
of food and packaging materials, and enhancement
of packaging barrier properties - all while maintaining
food quality and safety.

Approaches for Industrial Applications of
Cold Plasma Technology
The application of cold plasma in food processing
can be categorized into two types based on the mode
of treatment. The first is direct cold plasma
treatment, where plasma is generated and applied
directly onto the surface of food products. Examples
of food groups studied in previous research include
fresh fruits and vegetables, bakery products, cereals,
and grains. The second is indirect cold plasma

MAY 2025 FOOD FOCUS THAILAND 47

24/4/2568 BE 13:33
44-47_Smart Pro_�������.indd 47 24/4/2568 BE 13:33
44-47_Smart Pro_�������.indd 47