Jung Han. Innovations in Food Packaging
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110 Innovations in Food Packaging
Antimicrobial packaging
Among the various natural antimicrobial agents, nisin, a polypeptide produced by
Lactococcus lactis, has been most widely studied for its incorporation into packaging
films. Because it is produced by a safe food-grade bacteria, has been consumed by
humans for a long period of time without any recognized problems, and can be
degraded in the human gastrointestinal tract by proteolytic enzymes, it is ideal for use
as a biopreservative in foods. Nisin, a hydrophobic protein, has been granted GRAS
(generally recognized as safe) status for its use in cheese products in the USA, and is
effective against a wide range of spoilage and hazardous gram-positive bacteria (Hurst,
1983).
Many recent studies have reported that nisin-incorporated packaging materials
inhibit the growth of gram-positive bacteria, such as Brochothrix thermosphacta,
Lactobacillus helveticus, Listeria monocytogenes, Micrococcus flavus, and Pediococcus
pentosaceus (Daeschel et al, 1992; An et al., 2000), and have also extended the shelf
life of perishable foods by suppressing the growth of spoilage bacteria (Siragusa
et ai, 1999; Kim et ai, 2002a). Nisin can withstand moderate thermal processing and
exposure to acidic environments without major activity loss (Ray, 1992), which con-
fers high merit for the incorporation in food packaging materials. It is stable in a dry
form for years, and thus is expected to be safe when incorporated into the polymer
structure (Riick and Jager, 1995; An et aL, 2000).
Daeschel et al. (1992) treated silicon surfaces to absorb nisin so as to retain its
antimicrobial activity. L. monocytogenes cells exposed to the surfaces failed to grow,
and lost their metabolic activity (Bower et al., 1995). Higher amounts of nisin were
absorbed onto surfaces with high hydrophobicity, but such nisin possessed less anti-
microbial activity than that which was absorbed onto surfaces of lower hydrophobicity.
Scannell et al. (2000) fabricated cellulose-based packaging inserts absorbed with
nisin, which retained its antimicrobial activity and was effective against L. lactis.
Listeria innocua and Staphylococcus aureus. Cutter and Siragusa (1997) immobilized
nisin onto edible alginate gels to be ground with beef tissue. Extrusion of low-density
polyethylene (LDPE) containing nisin, at moderately low temperatures of 120°C, has
been reported to retain the antimicrobial activity of nisin in its plastic structure
(Siragusa et al., 1999). The nisin-fiUed film was seen to inhibit bacterial growth on meat
surfaces. However, extrusion or heat-setting at high processing temperatures, above
140°C, resulted in a complete loss of nisin's activity due to its denaturation (Hoffman
etal., 1998).
Owing to the possible antimicrobial activity loss during thermal processes, solution
coating or solvent casting processes have attempted to incorporate nisin into the pack-
aging matrix. When a preservative is incorporated into or added as a surface layer onto
the film structure by coating or solvent casting processes, the total amount of active
substance and the corresponding material costs can be reduced. On the other hand,
when a preservative is incorporated into the whole film structure by extrusion, a larger
amount of the preservative is needed to mix with the entire resin. An LDPE film
coated with nisin and a polyamide binder have also suppressed the microbial growth
of M. flavus andZ. monocytogenes in phosphate buffer solutions when in contact with
Packaging containing natural antimicrobial or antioxidative agents 111
the film (An et
al.,
2000). The plastic films with nisin inhibited the microbial growth
of total aerobic and coliform bacteria on shelled oysters and on ground beef at 3° and
10°C,
as well as extending the products' shelf life significantly (Kim et
aL,
2002a).
Therefore, it has been proposed that solution coating on the food contact surface can
provide more effective antimicrobial activity (An et al, 2000; Kim et
aL,
2002a). A
thinner coating with higher concentrations of nisin possessed higher antimicrobial activ-
ity compared to a thicker coating with lower concentrations of nisin (An et
al.,
2000).
When nisin
(0.1%
concentration) was incorporated into LDPE by extrusion, it did
not migrate into distilled water at room temperature, however, it migrated into saline
water that contained a surfactant (Siragusa et aL, 1999; Table 7.2). A heating treat-
ment (at boiling temperature) or a mild surfactant treatment caused the migration of
nisin from the LDPE film. It was thus suggested that nisin was not chemically bound
to the LDPE structure (Siragusa et al, 1999). Kim et ai (2000) also showed that the
presence of salt in food simulants increased the equilibrated migration level of nisin
from a polyamide coating layer. However, the incorporation of sodium chloride, citric
acid, and a surfactant into the coating medium did not enhance nisin's migration, nor
the film's antimicrobial activity (Kim et a/., 2000). It was therefore suggested by Chi-
Zhang et
al.
(2004) that controlled releasing nisin-incorporated packaging materials
could be combined with direct nisin addition into foods for more effective antimicro-
bial activity against
L.
monocytogenes.
The type of polymer affects the migration rate and the equilibrium concentration.
Kim et
al.
(2002b) reported that
a
vinyl acetate-ethylene copolymer coating
on
paper-
board caused a higher migration level of nisin compared to an acrylic polymer. The
diffusion coefficients of nisin in an acrylic polymer and in a vinyl acetate-ethylene
copolymer coating at 10°C were in the range of 1.1 X 10~^^ to 4.2 X 10"^^m^s"\
and 6.8 X 10"^^ to 12.2 X 10~^^m^s~\ respectively. The migration of nisin from
polyvinyl alcohol (PVOH) at ambient temperature has a diffusion coefficient ranging
from3.01 X
10"^"^
to 8.61 X
10"^^
m2s"\ with a partition coefficient of 26-153 as a
concentration ratio in the polymer to the simulant (Buonocore et al, 2003). The diffu-
sion coefficient in a swollen polymer matrix decreased with increasing cross-linking
Table 7.2 Activity of migrated nisin from nisin-impregnated LDPE film
Extraction conditions Film with 0.1% Film with 0.1% Film with 0.05%
active nisin active nisin active nisin
(7 min. extrusion) (14 min. extrusion) (7 min. extrusion)
Water for 315 min. at room temperature - -
Boiling water (100°C) for 5 min. + + +
Boiling in
0.02N
HCI solution for 5 min. + + +
Saline water + 0.5% Tween 20 + + +
at room temperature
Saline water + 0.5%Tween 20 + + +
at boiling for 5 min.
From Siragusa
etal.
(1999), reproduced with permission.
Innovations in Food Packaging
ratio and partition coefficient. Higher partitioning of nisin in the polymer provides a
great benefit to slow-release mechanics (Han, 2003). Cast films of biopolymers
demonstrated higher migration profiles of nisin activity compared to the heat-pressed
films (Cha et al, 2003).
Although changing the coating materials resulted in significant differences in the
suppression of microbial growth in water and in microbial mediums, no antimicrobial
activity difference was found in coating materials used in real foods, such as pasteur-
ized milk and orange juice (Kim et aL, 2002b; Figure 7.1). The suppression of the
microbial growth in real foods does not exhibit the same results as those in food sim-
ulants and in microbial mediums (Appendini and Hotchkiss, 2002).
Other bacteriocins, such as pediocin and lacticin, have also been incorporated into
packaging
films
to create antimicrobial packaging systems (Ming et ai, 1997; Scannell
et ai,
2000).
Nisin and other bacteriocins can inhibit gram-positive bacteria; however,
they are ineffective against molds, yeasts and gram-negative bacteria, with the exclu-
sion of a few strains (Hurst, 1983). There have been some approaches to improving
10
E
8^
4H
Micrococcus flavus in nutrient broth
contacting 5% nisin-incorporated coatings
Aerobic bacteria in milk contacting 3% A
H nisin-incorporated coatings /
J
-]
A
d
/
•^'
Time (days)
4 6
Time (days)
10
250
^ 200 H
c
o
150
100
50
Nisin migrated from 5%
nisin-incorporated coatings
Time (days)
14
12
10
8
6
4
2
Yeasts in orange juice contacting 3%
nisin-incorporated coatings
A
0-: .—^'^c
4 6 8
Time (days)
10
12
Migration and microbial growth profiles in food simulant or microbial medium contacting nisin-coated paper at 10°C. O,
acrylic polymer coating only; D, vinyl acetate-ethylene copolymer coating only; •, acrylic polymer with nisin; •, vinyl acetate-ethylene
copolymer with nisin. From Kim eta\. (2002b), reprinted with permission of John Wiley & Sons Ltd.
Packaging containing natural antimicrobial or antioxidative agents 113
the effectiveness of bacteriocin-incorporated packaging materials by incorporating
chelating agents such
as
EDTA (Nicholson,
1998).
A
higher hydrophobicity at an acidic
pH was reported to exert higher inhibitory activity of nisin against
L.
monocytogenes
in the edible
films
including whey protein, soy protein, egg albumin, and wheat gluten
(Ko era/., 2001).
Appendini
and Hotchkiss (1997) have
immobilized the antimicrobial agent, lysozyme,
in PVOH, nylon and cellulose triacetate (CTA) films. CTA films incorporated with
lysozyme demonstrated
the
highest antimicrobial activity against
Micrococcus
lysodeik-
ticus.
Higher antimicrobial activities were obtained when larger amounts of lysozyme
were incorporated, up to 150-200
mg
enzyme/g polymer, while the film thickness
did not affect the activity significantly. The antimicrobial activity of lysozyme may be
reduced due to its conformational changes when lysozyme is adsorbed onto a solid
surface (Bower et a/., 1998). Release of lysozyme in PVOH film at ambient tempera-
tures had a diffusion coeflficient of 3.83 X
10"^^
to 9.98 X 10"^^m^s"^ with
a
partition
coefficient of
6
to
432
(Buonocore,
2003).
Increasing the cross-linking degree decreased
the diffusion coefficient and increased the partition coefficient of
lysozyme.
Glucose
oxidase may be immobilized in a polymer matrix to confer antimicrobial activity, due
to a catalysis reaction yielding hydrogen peroxide from glucose and oxygen (Appendini
and Hotchkiss, 2002).
Chitosan is a biopolymer with good antimicrobial abilities, because it inhibits the
growth of a wide variety of fungi, yeasts and bacteria. In addition, it forms a film
almost by itself after it has been dissolved in acid solution (Begin and
Van
Calsteren,
1999).
It is a cationic polysaccharide of
(3-1,4
linkages obtained by the deacetylation
of chitin, which is collected from cructaceans or various fungi. Commercial chitosan
products usually have a molecular weight ranging from
100 000
to 1200
000
daltons,
but oligomer products with lower molecular weight can be produced by thermal,
enzymatic, and/or chemical degradation (Li et
al.,
1997). Chitosan is readily soluble
in various acidic solvents, and has high antimicrobial activity against many patho-
genic and spoilage micro-organisms (Tokura et
al.,
1997;
Tsai et al, 2002). However,
the antimicrobial activity of chitosan depends on its molecular weight, and the degree
of deacetylation and of chemical degradation. Tokura et al (1997) observed growth
inhibition of
Escherichia
coli by chitosan of molecular weight 9300g/mole, but not
by that of molecular weight 2200
g/mole.
Tsai et al (2002) reported that the anti-
microbial activity of chitosan increased with the degree of deacetylation. Both gram-
positive and gram-negative bacteria were inhibited by antimicrobial LDPE films
incorporated with chitosan above 1.43% in LDPE (Park et a/., 2002). Chitosan incor-
porated in LDPE could be released into the culture broth. Chito-oligosaccharide was
immobilized on PVOH by chemical cross-linking, and exhibited reduction in
S.
aureus
bacterial counts in culture medium (Cho
et
al, 2000). Chitosan
films
can also
be used as a delivery system for organic acids to exhibit antimicrobial functions
(Ouattarae^a/., 2000).
Different plant extracts have been used for antimicrobial packaging purposes.
Extracts of grapefruit seed. Rheum palmatum and
Coptis chinesis
have been included
into LDPE films by extrusion (Chung et al, 1998; Lee et al, 1998; Ha et al, 2001).
Grapefruit seed extracts in a solution form in glycerol, and in a powder form, have
114 Innovations in Food Packaging
been added
in
master-batch compounding
for
film fabrication. Other alcohoHc
or
aqueous plant extracts have been dried by freeze drying
or
spray drying, and have
been blended with polymer pellets to produce films (Chung et
al.,
1998).
The extracts
retained partial antimicrobial activity after the thermal extrusion process. Grapefiiiit
seed extract exhibits
a
wide spectrum
of
microbial growth inhibition,
and has
been reported
to
contain naringin, ascorbic acid, hesperidin, and various organic acids
such
as
citric acid.
In
addition,
in
some countries
it is
permitted
for
use
as a
food
additive (Sakamoto et
ai,
1996; Lee et
ai,
1998). Its water-soluble
fi*action
has anti-
microbial activity and contains three reactive components identified by gas chromato-
graphy
(Cho et al,
1994). Sakamoto
et al.
(1996) identified triclosan
and
methyl-p-hydroxybenzote to be the active antimicrobial components in grapefinit seed
extract. Kim
et
al.
(1994) reported
the
existence of antimicrobial chitinase
in the
extract,
which is stable to heat
treatments.
The antimicrobial activity of grapefruit seed extract
was stable at high temperatures of up to 120°C (Kim and
Cho,
1996), and
was
retained
after film fabrication processes (Lee
et al,
1998). Films containing grapefruit seed
extracts were effective
in
inhibiting the growth
of
aerobic bacteria and/or coliforms
on
fi*esh
produce and on ground
beef,
when contact packaging was used (Chung et al.,
1998;
Lee et
al,
1998; Ha et
al,
2001).
Another plant extract used for commercial antimicrobial packaging
is
wasabi extract,
or Japanese horseradish (Koichiro,
1993).
The main active antimicrobial ingredient in
wasabi extract
is
known
to be
the volatile allyl isothiocyanate (AIT). The AIT
gas
inhibits many fiingi and
bacteria.
The minimal inhibition concentration of AIT against
Yersinia enterocolitica
and L.
monocytogenes
is in the
range
of
14-145
ppm
at
10^0°C (Kusunoki et
al,
1998). The extract has been encapsulated in cyclodextrin
to control the volatility of AIT (Figure 7.2). The AIT in the encapsulated powder (dry
form) is suggested not to be volatile, but becomes volatile when
the
AIT-cyclodextrin
100
Relative humidity (%)
Figure
7.2
Volatility
of
allyl
isothiocyanate encapsulated
in
different matrixes.
•,
zeolite;
•,
cyclodextrin.
From Koichiro (1993).
Packaging containing natural antimicrobial or antioxidative agents 115
complex is exposed to high humidity conditions after the packaging of the food prod-
uct (Koichiro, 1993). The evaporated AIT then migrates to the food surface, and
inhibits the growth of aerobic bacteria such
as Aspergillus
niger,
Penicillium
italicum,
S. aureus, and
E.
coli. Stronger antimicrobial activity of AIT was reported at higher
RH, suggesting that moisture has a significant fimction in AIT's antimicrobial ability
(Furuya and Isshiki,
2001).
The
AIT-cyclodextrin complex powder
has
been incorpo-
rated in packaging materials of drip sheets, polyethylene films, and tablets. These
products are commercially available in Japan, and are used for
rice
lunch
boxes,
meats,
and
firesh
produce. A design of the drip sheet is shown in Figure 7.3.
Volatile components from essential oils of mustard, cinnamon, garlic and clove have
been added
to
filter
papers to inhibit spoilage
fimgi
in
breads,
such as Aspergillus flavus,
Endomyces fibuliger, and
Penicillium
commune (Nielsen and Rios, 2000). Nielsen
and Rios (2000) have suggested using AIT from mustard as the active component in
the packaging of bread.
Packaging materials incorporating a single biopreservative have limitations in
ensuring the safety and extending the shelf life of
foods,
because they can only inhibit
specific microbes. For example, nisin-incorporated packaging materials suppress the
growth of gram-positive bacteria effectively (Daeschel
et
ah,
1992;
Bower
et
al.,
1995;
Siragusa et
al.,
1999;
An et
al.,
2000), but it does not work against gram-negative bac-
teria such as E. coli (Cha et aL, 2002). However, a narrow antimicrobial spectrum
may, in certain cases, be desirable for packaged foods in which microbial contamina-
tion is caused by only a specific type of strain. Nonetheless, generally packaging
materials with a wide antimicrobial spectrum are more desirable for universal use and
to improve the storage stability of
a
variety of food products. In an effort to achieve
this,
Cha et al. (2002) incorporated several antimicrobial agents into films made of
Na-alginate and K-carrageenan. The addition of EDTA and grapefruit seed extract to
both
films
gave a strong inhibition against
Micrococcus
luteus,
L.
innocua,
Salmonella
enteritidis,
E.
coli, and
S.
aureus;
however, Na-alginate based films with the addition
of nisin, lysozyme, and EDTA showed the strongest inhibition against the same bac-
terial strains. Table 7.3 shows their Na-alginate based film results.
In a similar approach, Lee
et
al.
(2003) fabricated
a
paperboard coated with nisin and
chitosan combinations which had been dissolved in
a vinyl
acetate-ethylene copolymer.
Perforated polypropylene film
Cyclodextrin layer with
wasabi extract
Non-woven fiber layer
Figure 7.3 Design of drip siieet incorporating wasabi extract. From Koichiro (1993).
116 Innovations in Food Packaging
Table Z3
^f^setsiio^w^
in JMa-adginate
filmsj
on several organisms
Film
Strain
Micrococcus luteus
Listeria
innocua Salmonella enteritidis Escherichia coli
ATCC10240 ATCC 33090 ATCC14931 ATCC 9637
Staphylococcus aureus
ATCC 25923
Control without
antimicrobial additive
With nisin
With lysozyme
With nisin + EDTA
With lysozyme + EDTA
With nisin + lysozyme + EDTA + + + + + + + + + + + +
With EDTA
With EDTA + grapefruit ++ ++ + + +
seed extract
With grapefruit seed extract
-, no inhibition; +, weak inhibition (<2 mm in inhibition zone); + +
,
inhibition zone of 2-5 mm; + + +
,
strong inhibition with
diameter >5 mm. From Cha
etal.
(2002), reproduced with permission.
+ +
+
+ +
+
+ + +
+ +
+ +
+
-1-
- + +
- +
Nisin and chitosan migrated into water and equilibrated at about 8% for nisin and 1%
for chitosan. In addition, the release rates and levels were not affected by the presence
of other preservatives in the polymer coating. Nisin and chitosan in an acidified vinyl
acetate-ethylene copolymer coating layer exhibited strong microbial inhibition against
L
monocytogenes
and
E.
coli 0157:H7, and improved the microbial quality of milk
and orange juice stored at 10°C. Cha et
al.
(2003) also designed chitosan films con-
taining nisin with a strong antimicrobial activity against M luteus.
Antimicrobial packaging systems containing natural antimicrobial agents can con-
fer specific or broad microbial inhibition, depending on the agents used and their con-
centrations. Different types of antimicrobial-delivery mechanisms, polymers, and
packaging material - food combinations
may be
appHed or used
to
maximize the effec-
tiveness of the system.
%rTi:!OYidative packaging
Antioxidants
can be
incorporated
into
or coated
onto
food packaging materials to control
the oxidation of fatty components and
pigments,
and thus can contribute to the quality
preservation of foods (Vermeiren
et
al,
1999).
The antioxidants incorporated
into
plastic
packaging materials may have the dual role of protecting the polymer as well as the
packaged food from oxidation (Waite, 2003). Antioxidative packaging can retard the
oxidative reactions of fatty ingredients in packaged foods. The incorporation of syn-
thetic antioxidants, such as butylated hydroxytoluene (BHT) and butylated hydroxy-
anisole (BHA), in high-density polyethylene (HDPE) liners have been shown to protect
cereals from oxidation (Miltz
et
a/.,
1988;
Wessling et al, 2001). However, because of
the growing concern about the use of food chemicals, there is greater interest in using
Packaging containing natural antimicrobial or antioxidative agents 117
CD
O
c
CO
1-
o
<fi
CO
c
o
CO
•D
Time (days)
Figure 7.4 Effect of a-tocopherol-incorporated LDPE film on the oxidation of linoleic emulsion at 6°C.
•, no addition; A, added in 360 ppm; #, added in 3400 ppm. From Wessling
etal.
(2000), reprinted with
permission of John Wiley & Sons Ltd.
natural antioxidants such
as
a-tocopherol
and ascorbic
acid.
In particular,
a-tocopherol
can be easily dissolved into polyolefins and does not break down under pol3aner pro-
cessing
conditions.
A significant concentration of
a-tocopherol
also usually remains in
the final plastic films (Ho et
aL,
1998; Wessling et al, 1999). Zambetti et al (1995)
found that the use of
a-tocopherol
as an antioxidant in LDPE used in extrusion coating,
and in HDPE used in extrusion-blown
bottles,
improved
the
sensory performance of the
bottled water by preventing the oxidation of the polymer substrates. Wessling et al.
(1999) found that
a-tocopherol
incorporated
into
polypropylene
(PP)
retained more of its
activity than when incorporated into LDPE, when both
films
were in contact with vari-
ous foods and food-simulating
liquids.
The
a-tocopherol
in LDPE
decreased at consider-
ably higher
rates
with high fat-containing foods or with high-alcohol
liquids.
Therefore,
LDPE containing an active antioxidant can offer
the
potential of being used
as
an active
packaging because it can help to transfer
the
incorporated
a-tocopherol
onto the pack-
aged foods, which will help prevent
the
oxidation of the food
products.
PP may
be
used
as oxygen-scavenging packaging in the headspace or at the packaged foods' surface.
LDPE
films
that incorporated
a-tocopherol
above 360 ppm delayed the oxidation of
linoleic acid emulsions at
6°C
(Figure 7.4), but did not
do
so at
20°
and
40°C
(Wessling
et al, 2000). LDPE films containing
a-tocopherol
above 700 ppm could not prevent
the oxidation of oatmeal at
20°C;
this
is
probably due to the poor contact of the packag-
ing
fihn
with
the
oatmeal product (Wessling
et
al,
2001).
For a-tocopherol-incorporated
films to be effective, it is necessary that there is close contact between the packaging
material and the food product. The
a-tocopherol
in the film is degraded chemically
without volatiles being
loss,
while BHT diffuses out of the
film
and
is
volatilized
on
the
surface, eventually migrating to the dry food (Miltz
et
al,
1988;
Wessling et al, 2001).
Another concern with
a-tocopherol
being incorporated into LDPE films is the
potential changes it causes in the mechanical properties, color, and oxygen perme-
ability of the film (Wessling et al, 2000).
Innovations in Food Packaging
Ascorbic acid can scavenge oxygen in the headspace air of canned or bottled prod-
ucts.
Its ability to scavenge oxygen has made it a possible candidate for scavenging
oxygen in active food packaging technologies (Smith et ah, 1995). Ascorbic acid in
combination with other antioxidants can act as an antioxidant, and can retard rancidity
(Yanishlieva-Maslarova, 2001). It can also protect against the peroxidation of lipid
components by trapping the peroxyl radical in the aqueous phase. Due to this, the
antioxidative property of ascorbic acid
has
been incorporated into and used in the fab-
rication of oxygen-scavenging plastics (Rooney, 1995).
Perishable foods that are sensitive to both microbial spoilage and oxidative deteri-
oration
may be
packaged in polymeric materials containing both antimicrobial and anti-
oxidant
additives.
Lee et
al.
(2004) produced antimicrobial and antioxidant packaging
materials that incorporated nisin and/or a-tocopherol. They examined their effective-
ness with an emulsion model system and in milk cream. At 10°C, a-tocopherol
migrated into an oil-in-water emulsion at a faster rate and reached an equilibrium
level at about 6%, while nisin migrated at about 9%. Therefore, the inclusion of both
a-tocopherol and nisin in coated paper could provide antimicrobial and antioxidative
functions. However, no synergic or interactive effects in the antimicrobial or anti-
oxidative activities were observed by the use of the combination (Lee et al, 2004).
One application combining ascorbic acid and silver zeolite has been reported for
antioxidative and antimicrobial activity (Rooney, 1995).
Antimicrobial and antioxidative packaging systems containing natural active sub-
stances may have high
potential for commercial food packaging
applications.
Consumers
would prefer to obtain better food safety of fresh produce and minimally processed
foods using this type of packaging system. However, it is necessary that new active
packaging systems must satisfy food safety regulations, which are different in each
country. Greater food safety and quality assurance may be improved by the use of
both antimicrobial and antioxidative packaging systems incorporating natural active
agents. Some commercial products, such as films coated with wasabi extract, are
already on the market and satisfy the regulations and consumer needs of particular
countries. Most materials containing natural active agents are more effective when
there is direct contact of the packaging materials with the food
product.
For new pack-
aging systems to be introduced into the market effectively, careful design is required.
Natural antimicrobials and antioxidants are usually costly, and therefore further devel-
opment of package design using the minimum of active agents is desirable for practi-
cal applications. Food contact layers with the appropriate concentrations of the active
agents may be laminated or coated onto the barrier layer of the package structure.
There are some suggestions that before long many countries would adopt the new
active packaging concepts into their packaging regulations. Therefore, new applica-
tions of antimicrobial and antioxidative packaging are likely to be available in the
market sooner or later.
Packaging containing natural antimicrobial or antioxidative agents 119
References
An, D. S., Kim,
Y.
M., Lee, S. B., Paik, H. D. and Lee, D. S. (2000). Antimicrobial low
density polyethylene film coated with bacteriocins in binder medium. Food Sci.
Biotechnol 9,14-20.
Appendini, P. and Hotchkiss, J. H. (1997). Immobilization of lysozyme on food contact
polymers as potential antimicrobial films.
Packag.
Technol Sci. 10, 271-279.
Appendini,
P.
and Hotchkiss, J. H. (2002). Review of antimicrobial food packaging. Innov.
Food Set Emerg.
Technol.
3,113-126.
Begin, A. and Van Calsteren, M. (1999). Antimicrobial films produced from chitosan. Intl
J. Biol. Macromol. 26, 63-67.
Bower, C. K., McGure, J. and Daeschel, M. A. (1995). Protein antimicrobial barriers to
bacterial adhesion. Appl. Environ. Microbiol. 61, 992-997.
Bower, C. K., Daeschel, M. A. and McGuire, J. (1998). Suppression of Listeria monocy-
togenes colonization following adsorption of nisin onto silica surfaces. J. Dairy Sci.
81,2771-2778.
Buonocore, G. G., Del Nobile, M. A., Panizza, A., Corbo, M. R. and Nicolais, L. (2003).
A general approach to describe the antimicrobial agent release from highly swellable
films intended for food packaging applications. J.
Contr.
Release 90, 97-107.
Cha, D. S., Choi, J. H., Chinnan, M. S. and Park, H. J. (2002). Antimicrobial films based
on Na-alginate and K-carrageenan. Lebensm.
Wiss.
u.
Technol.
35, 715-719.
Cha, D. S., Cooksey, K., Chinnan, M. S. and Park, H. J. (2003). Release of nisin from
various heat-pressed and cast films. Lebensm.
Wiss.
u.
Technol.
36, 209-213.
Chi-Zhang, Y, Yam, K. L. and Chikindas, M. L. (2004). Effective control of Listeria
monocytogenes by combination of nisin formulated and slowly released into a broth
system.
IntlJ.
Food
Microbiol.
90, 15-22.
Cho,
S. H., Chung, J. H. and Ryu, C. H. (1994). Inhibitory effects of natural antimicrobial
agent on postharvest decay in fruits and vegetables under natural low temperatures.
J. Korean Soc. Food Nutr 23,
315-321.
Cho,
Y W., Han, S. S. and Ko, S. W. (2000). PVA containing chito-oHgosaccharide side
chain. Polymer
41,
2033-2039.
Chung, S. K., Cho, S. H. and Lee, D. S. (1998). Modified atmosphere packaging of fresh
strawberries by antimicrobial plastic films.
Korean
J.
Food Sci.
Technol.
30,1140-1145.
Cutter, C. N. and Siragusa, G. R. (1997). Growth of Brochothrix thermosphacta in ground
beef following treatments with nisin in calcium alginate gels. Food Microbiol. 14,
425^30.
Daeschel, M. A., Mcguir, J. and Al-Makhalafi, H. (1992). Antimicrobial activity of nisin
adsorbed to hydrophilic and hydrophobic and hydrophobic silicon surfaces. J. Food
Prot. 55,731-755.
Furuya, K. and Isshiki, K. (2001). Effect of humidity on allyl isothiocyanate antimicrobial
activity. J. Japanese Soc. Food
Sci.
Technol.
(in Japanese) 48, 738-743.
Ha, J. U., Kim, Y M. and Lee, D. S. (2001). Multilayered antimicrobial polyethylene films
applied to the packaging of ground beef
Packag.
Technol.
Sci. 14, 55-62.
Han, J. H. (2000). Antimicrobial food packaging. Food
Technol.
54(3), 56-65.
Han, J. H. (2003). Antimicrobial food packaging. In: Novel Food Packaging
Technologies
(R. Ahvenainen, ed.), pp. 50-70. Woodhead Publishing, Cambridge, UK.