Worldwide
demand for food is expanding and will probably keep on going for decades,
impelled by 2.3 billion person

increment
in world population along with increase in per capita wages through middle of
this century (Godfray et al., 2010). So preservation of food
material is need of an hour. The primary goal of food preservation technologies
is to control and eliminate microorganisms along with maintaining the quality
and nutritional value of food. Till now food industries are using many thermal
technologies for food preservation but over past several decades, industries
are heading towards novel non thermal technologies to reduce the thermal impact
of heat based technologies This move is credited to different reasons,
including (1) consumer demand for safe and nutritious food products; (2)
process and energy efficiency; and (3) legislative and regulatory requirements
aiming to minimize the use of chemical preservatives (Ojha
et al., book chapter).  Several novel cold
processing technologies are introduced including irradiation, high pressure
processing (HPP), ultrasound, pulsed electric field, radio frequency etc. but
processes requires specialized
equipment, trained personnel and expensive too (Yun et al., 2010)

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

 

Cold plasma is
an innovative technology which recently been used in biological treatments
including sterilization and surface modification (Rodríguez et al., 2017). Reactive
oxygen species (ROS) like singlet oxygen, ozone, energized molecular nitrogen
are produced by cold plasma (Misra et al., 2014).  which helps in inactivation of several spoilage
microorganisms and food borne pathogens. (Brun et al., 2010; Niemira, 2012). Several studied
showed that the effective microbial destruction like inactivation of Escherichia
coli from fresh produce (Bermudez-Aguirre, 2013), Aspergillus
parasiticus and Penicillium sp from seeds of various vegetable,
legumes and cereals (Selcuk, 2008), Erwiniacarotovora in potatoes
(Moreau, 2007), Listeria monocytogenes from plastic trays, paper cups
and aluminum foil (Yun, 2010).

This
technology has successfully employed for surface decontamination of fresh meat,
poultry, fish, and fruits and vegetables (Fernandez et al., 2013; Noriega et
al., 2011; Ziuzina et al., 2014) and 
surface disinfecting of packaging material and enhancing functional
properties of these materials. (Güleç et al., 2006; Lee et al., 2015; Ozdemir et al.,
1999; Pankaj et al., 2014).  As cold plasma technology currently
trending area of research and liitle exploited by food industries so the aim of
this article is to provide current review of this innovative technologies, its
applications and significance in food industries and future scope of non
thermal technologies for food preservation.  

Princple /Mechanism

 

In
cold plasma technology plasma generation is the first and important step. Plasma,
a fourth state of matter is fully ionised gas composed of various substances
like electrons, free radicals, photons and excited state atoms with neutral
charge (Ekezie et al., 2017; Dasan et al., 2017). These
plasma particles have equal number of positive and negative ions thus possessing
net neutral charge. (Kudra
and Majumdar, 2009). Thermal and non thermal plasma two classification of
plasma are based on generation mechanisms of inducing varying temperature and
pressure by energizing neutral gas. Thermal plasma requires high pressure  (>105 Pa) and up to 50 MW of energy for its
proliferation, which is  likewise
recognized by a thermodynamic harmony between the electrons and heavier species
because of uniform gas temperature for all constituents (Scholtz et al., 2015). While non thermal plasma also known as near ambient temperature
plasma (NTP) is produced under atmospheric pressure at temperatures of
30-60°C requiring low power. These plasma do not require localized thermodynamic
equilibrium and hence known as non-equilibrium plasma.

 

 

 

  

                                       

 

 

 

When a high voltage is
applied on food material atmospheric gas get ionised and producing reactive
ionised species (ROS) , the microorganisms present inside the food material received
radical bombardment which provokes the lesions on the surface of cell that are
not healed by microorganisms and thus starts cell lysis. The accumulation
electrostatic forces on cells surface leads to lesion formation. This phenomenon
is known as etching. Along with microbial destruction ROS also interact with vital cellular
biomolecules, such as DNA, proteins and enzymes in cell. It also forms
unsaturated fatty acid peroxides from lipids and oxidise amino acids. (Misra

et al., 2016)

 

 

Applications:

 

Microbial destruction:

Microbial inactivation will
affect several quality parameters of food. The interaction of plasma ions with
microbial cells made it a inevitable processing technique with little damage to
food nutrients. Its antimicrobial efficacy had been studied on wide range
on  microorganisms (Dasan et al., 2017; McClurkin-Moore,
Ileleji, & Keener, 2017; Wang, Zhuang, & Zhang, 2016; Xu et al., 2017). Plasma reactive reactive interacts with DNA resulting in
formation of malondialdehyde (MDA) which
forms DNA adducts and thus damaging the microbial cells. These plasma species
also interacts with water forming OH* ions which are highly reactive and
harmful. These ions forms hydration around DNA and damaging 90% of  it. Hydroxyl radicals also reacts with other
cell components leading to chain oxidation which will damage them along with
cell membranes. (D. Dobrynin, G. Fridman, G. Friedman, A. Fridman doi:10.1088/1367-2630/11/11/115020),

 

 

The significant
reduction in E.
coli and L.
monocytogenes was studied on red chicory (Cichoriumintybus) keeping stable
conditions with 22°C temperature, 60% RH, varying time for 15 and 30 min and
keeping food material at 70mm difference from discharge of cold plasma (Pasquali
et al., 2016).
Choi et al. (2017) showed the effect of corona
discharge plasma on dried squid at 20 kV (58
kHz) for 0 to 3 min and 2.0, 1.6 and 0.9 log reduction was observed for aerobic
bacteria, marine bacteria and Staphylococcus aureus, respectively with very
less nutritional changes. The 40 min duration of  microwave induced cold plasma significantly
inhibit B. cereus, A. brasiliensis, and E. coli O157:H7 by 2.1, 1.6 and 1.9 log CFU/cm2,
respectively, after 21 days against onion powder without affecting color and
antiodiant property of sample (Kim, Oh, Won,
Lee, & Min, 2017).

 

 

Packaging material

 

Packaging materials
are solely responsible food materials protection during handling, transportation
and distribution. So a good packaging material with better sustainability and functionality
provide better protection to food materials inside it. The innovative plasma
technology providing high potential in food packaging as it improves adhesion
properties, polymerization and aids in good printability (Pankaj et al.,
2013). This technology helps in external decontamination of packaging material (Shakila
et al., 2012), improved fuctionalization, etching and deposition as plasma is
streaming all round the surface. Surface fuctionalization involves inclusion of
functional groups and turnable surface energies to
material with a specific end goal to affect antimicrobial properties and
upgrade mechanical properties (Contini et
al., 2014; Pankaj et al., 2014; Sen & Mutlu, 2013). It also helps in keeping up sealing properties of polymer
foils or laminates (Heise, Neff, Franken, Muranyi,
& Wunderlich, 2004).

x

Hi!
I'm Erica!

Would you like to get a custom essay? How about receiving a customized one?

Check it out