Development of active edible coating and
biodegradable packaging for food
application
Monique Lacroix, Ph.D.
Professor
Research Laboratories in Sciences Applied to Food
INRS-Institut Armand-Frappier
531 des Prairies blvd.
Laval city, Québec, Canada H7V 1B7
Monique.lacroix@iaf.inrs.ca
www.iaf.inrs.ca
Tel: 1 450 687 5010 ext 4489
International Conference and Exhibition on
Biopolymers and Bioplastics
August 11,2015, San Francisco, USA
©INRS, 2014
Edible coating: definition
Primary purpose of food coating is to provides a barrier to
microorganisms, to moisture, to gas and to solute migration
in food.
Edible coating is normally applied on food surface and where
a thin layer edible film is formed directly on food surfaces or
between different layers.
Edible coating: potential
Edible coatings can
Extend the shelf life of the food by the inhibition of the microbial growth
and by the improvement of the quality of food system
• Preservation of bioactive nutrients
• Inhibition of oxidation (inhibition of gaz transfert)
• Preservation of physico-chemical (ex: texture, color) and organoleptic
properties of food
• Protection of probiotic bacteria viability
Biobased packaging
Packaging containing raw materials
originating from agricultural sources
produced from renewable, biological raw
materials such as starch, cellulose and
bio-derived monomers
Global market of packaging
$ 417 Billion
100 000 industries
5 Millions employees
Food Packaging represent
65% of the market
USA: $100 Billion
Japan: $80 Billion
Germany: $29 Billion
France: $19 Billion
Driving in coating and
packaging innovation
Increasing consumer demand for ready to eat foods
Environmental issue: recycling, biodegradability
Request for fewer or no additive and preservation
Change in retail and distribution practices associated with
globalization
Stricter requirements regarding consumer health and safety
Post-process contamination
66% of the post-process contamination is
caused by
Product mishandling
Faulty packaging
PROBLEMATIC ISSUES
The Center for Disease Control and Prevention (CDC) estimates
that 48 million people get sick due to foodborne diseases in
USA annually.
In Canada, the foodborne illness is estimated as more than 11
million episodes/year
→ Therefore, controlling of food pathogens in food
products are very important.
Listeria
Salmonella
E.coli
Campylobacter
Post-processing protection by
Active packaging
Active coating
Has been proposed as an
Innovative approach
that can be also applied to ready-to-eat
products to minimize or prevent the growth of
pathogenic microorganisms
Active edible coating and packaging
refers to the incorporation of additives
or extracts from natural sources into
packaging or coating systems to
increase the shelf life of foods and then
to provide a high-quality products
(fresh/safe).
Active Coating and Packaging
Active coating and packaging allow
interaction with food products and the
environment and play a dynamic role
in food protection
Active packaging
Delay oxidation
Delay microbial growth
Assure innocuity of foods
Control the respiration
Delay moisture migration
Absorb CO2
Remove ethylene and aroma emitters
Absorb drip
Better protection of the food quality and reduce the
waste level
Example of edible coating:barrier properties
• Rancidity
• Chocolate  firm
• Fat bloom
Rejection by the
consumer
Return the product to
the producer
edible coating: transport limitation of unsaturated fatty acids
Chocolate
almond
Oil
Results
Diffusion of oil based on the addition of
various polymers
Milk proteins have high nutritional value
They are available in large amounts world-wide
They have been extensively investigated as edible coatings
and films
Edible coating: antioxydant properties
Application against the browning of fresh fruits and vegetables
  enzymatic browning
 Stabilizing the whiteness of the product
90
80
L*
70
Control
60
50
40
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
5
temps (heures)
Coated
contrôle
caséinate
lactosérum
L+C
Edible coating:antimicrobial properties
Application against the growth of molds on strawberries
 Protective barrier against moisture
  shelf life of strawberries
100
Contamination (%)
80
60
40
20
Control
Base
Base+PLS
0
0
10
20
Storage time (days)
30
40
Chitosan
O
HO
NH2
O
O
O
HO
OH
OH
OH
OH
O
O
NH2
O
HO
NH2
O
HO
NH
O
CH3
Natural polysaccharides, the second most abundant
after cellulose
Poor mechanical properties, lack of water resistance
High water permeability
High gases barriers
It has a broad antimicrobial spectrum
Effective carriers of many active compounds
Chemical modification of chitosan
N-acylation of chitosan
 Functionalization of chitosan with fatty acid derivatives
allowed 
hydrophobicity and emulsifiying properties
 Stabilization of active compounds in chitosan
(encapsulation matrix)
According to Han et al. (2008)
b) PLA-NCC-nisin film
3450-3150
Modified chitosan-based coating on strawberries
In situ antimicrobial activity
 RT, PM EOs and LIM were
the most efficient
preservative agents in
strawberries during
storage.
 Efficient method to
preserve the quality of
strawberries up to 12 days
Evolution of the decay level (%) in antimicrobial coated strawberries during storage.
b) PLA-NCC-nisin film
Modified chitosan-based coating on strawberries
In situ antimicrobial activity
Appearance of strawberries coated with modified chitosan-based formulation
containing limonene and emulsifiers.
3450-3150
Encapsulation for the preservation of Nutrients and
functional products using modified chitosan
Retention of -caroten (%)
during storage at 45 ºC and 100% RH
after encapsulation with modified chitosan
100%
80%
60%
40%
Formulation 4
Formulation 3
Formulation 2
Formulation 1
20%
0%
0
1
2
Non encapsulé
3
Temps (mois)
4
5
6
LAB
• Protection during gastro
intestinal passage
 encapsulation in polymer
Based on modified chitosan,
Modified alginate
10 9
pH 1.5 -2.5
 10 6-10 7
Bacteria
polymer
Viability of L. rhamnosus RW-9595M
***
**
*
* *
*
(FC: Free BAL; NA: native alg.; SA: modified alg. ;
SC: modified chitosan; PA modified alg.).
The use of edible coating in combined
treatment
to increase the antimicrobial property
Coating application of modified chitosan-based
coating on ready to eat vegetables
0
0
Control (air)
Coating (air)
MAP
MAP+Coating
-1
-2
-2
Log N/N0
Log N/N0
Control (air)
MAP
Coating (air)
MAP+ Coating
-1
-3
-4
-4
0.083
0.383
0.295
0.061
-5
-3
0.110
-5
0.102
0.202
-6
0.332
-6
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Irradiation doses (KGy)
Radiosensitization of E. coli on green
bean samples as affected by coating
formulation under various atmospheres
0.0
0.5
1.0
1.5
2.0
2.5
Irradiation doses (KGy)
Radiosensitization of S. Typhimurium
on green bean samples as affected by
coating formulation under various
atmospheres
D10 values of selected pathogens and total microflora
in broccoli florets coated with active coating
Bacteria
Control
OA/LAB
metabolites
OA/FE
OA/FE/SM
OA/SE
L.
monocytogenes
0.4
0.29
0.3
0.27
0.3
E. coli
0.38
0.2*
0.16*
0.24
0.23
S. Typhimurium
0.50
0.2*
0.29*
0.28*
0.25*
Aerobic flora
0.57
0.36*
0.32*
0.38
0.33
OA: organic acid mixture; LAB: mixture of LAB ferment; FE: fruit extracts;
SM: spice mixture; SE: spice extract
Irradiation treatment from 0 to 3.3 kGy
Effect of bioactive coating containing carvacrol in combination with modified
atmosphere packaging and gamma irradiation (0.25 kGy)
on population of E. coli on green beans samples during storage at 4 °C
Day 1
Day 3
Day 5
Day 7
Day 9
Day 11
Day 13
Control
2.98Aa
3.03Aa
3.10ABa
3.14ABa
3.18Ba
3.41Ca
3.95Da
MAP
3.02Aa
3.19Aa
3.05ABa
3.01ABa
2.80Bb
2.98ABb
3.01ABb
Coating (air)
2.45ABb
2.15Ab
2.57Bb
1.40Cb
1.25Cc
ND
ND
Coating+MAP
2.64Ab
2.59ABc
2.30Bb
1.66Cb
1.19Dc
ND
ND
γ (air)
1.71Ac
1.26Bd
1.18Bc
ND
ND
ND
ND
γ +MAP
1.62Acd
1.45Be
1.19Cc
ND
ND
ND
ND
γ+coating (air)
1.30Ad
1.35Ade
1.25Ac
ND
ND
ND
ND
γ+coating+MAP
ND
ND
ND
ND
ND
ND
ND
Values are means ± standard deviations. Means with different lowercase letters within the same column
are significantly different (P ≤ 0.05), while means with different uppercase letters within each treatment lot
are significantly different (P ≤ 0.05); MAP: (60% O2, 30% CO2, and 10% N2).
Bacterial population on refrigerated pizzas as
affected by gamma irradiation and edible coating based
on milk proteins
C,3 days
2 kGy, 14D
1-2 kGy > 21 D
8
8
1 kGy,12D
7
6
5
4
3
0 kGy
2
1 kGy
2 kGy
1
log CFU/g
6
Log CFU/g
C,17D
7
5
4
3
0 kGy
2
1 kGy
1
2 kGy
0
0
0
5
10
15
20
Storage time (d)
Irradiation alone
25
0
5
10
15
20
25
Storage time (d)
Irradiation + edible coating
The highly hydrophilic nature of protein coatings
can limits their functional utilization
Therefore, formations of cross- linked proteins can
produce a strong, flexible film or coating.
Formation of bityrosine in calcium caseinate films
as a function of irradiation dose
Fluorescence intensity
(a.u)
4000000
3500000
3000000
2500000
2000000
1500000
1000000
500000
0
Base
PEG
Sor
Man
0
8
16
32
64
Dose (kGy)
92 128
Fraction of insoluble matter in function of the irradiation dose
Results are expressed as the percentage in solid yield after soaking the
films 24 hours in water
80
Weight yield (%)
70
60
50
40
30
20
10
0
4
8
16
32
64
Dose (kGy)
96
128
Effect of crosslinked films based on milk proteins
containing essential oils on
E.coli 0157:H7 growth on beef
4,0
Log UFC/CM2
3,8
Beef without film
3,6
film with pepper
3,4
3,2
pepper +
origano extract
3,0
2,8
2,6
Origano extract
2,4
2,2
2,0
0
2
4
Temps (jour)
6
8
ADFs: New generation of antimicrobial device
CNC filling
in MC matrix
+
Trilayer film
PCL/MC/PCL
+
Encapsulation of
natural antimicrobials
Synthesis of Antimicrobial Diffusion Films (ADFs)
(to get advantage from complementary functional properties of
each component and process)
Characterization and application
Preparation of trilayer ADFs as diffusion devices
Principle scheme of compression molding process to prepare composite
trilayer ADFs (MC film content = 30% w/w, dry basis).
ADFs on fresh broccoli
Percentage of total phenolics (TP) release from ADFs during storage
1600
 FTIR analysis of volatiles diffusivity
of antimicrobials encapsulated in
ADFs (from day 0 to day 14).
 Continue diffusion (controlled
release) of volatiles can be
monitored by quantification of FTIR
bands:
• Aromatic stretching (1600 and 1515
cm-1)
• Ester antisym stretching (1265 cm-1)
1265
 Day 0
 Day 2
 Day 6
 Day 13
1515
FTIR spectra of bioactive ADF internal layer in fingerprint area (1200-1800 cm-1)
for the estimation of TP release (diffusion of volatiles).
ADFs on fresh broccoli
Percentage of total phenolics (TP) release from ADFs during storage
 Slow diffusion of antimicrobial
volatiles towards headspace
environment
 Slight  of diffusion to 14-17%
 Good correlation obtained between
the 2 methods (FTIR at 1600 cm-1 vs
Folin-Ciocalteu)
TP release (%) from bioactive ADFs during storage, deduced from TP availability
in films by Folin-Ciocalteu‘s method.
ADFs on fresh broccoli
Microbiolgical analysis
 Total inhibition of E. coli at
day 12
 Stronger effect of
formulation A at day 4
Antimicrobial effect of trilayer ADFs on E. coli during storage of broccoli (12 days
at 4°C).
ADFs on fresh broccoli
Microbiolgical analysis
 Total inhibition of S.
Typhimurium at day 7
 Stronger antimicrobial
efficiency against gramnegative bacteria
Antimicrobial effect of trilayer ADFs on S. Typhimurium during storage of
broccoli (12 days at 4°C).
.
Summary
Edible coating and Biodegradable packaging based on Natural polymers
can be used
• To protect food quality
• To carry natural antimicrobial compounds
The functionalisation of the polymer can improve the protection and the
release rate of the immobilized active compounds
Crosslinking reaction of natural polymers can improve the physicochemical properties of the films and their stability during storage time of
the packaged food
.
Summary
• ADFs (trilayer assembly) and encapsulation of natural
antimicrobials showed strong inhibiting capacity against E. coli and
S. Typhimurium over storage.
• These films could further be explored in food applications to
prevent pathogenic contamination during storage of fresh food,
based on a controlled release of volatiles into headspace of
packaging.
Summary
Edible active coating and packaging could be used
in combination with modified packaging and
pasteurization treatments to increase the bacterial
sensitivity and to assure food safety
Monique Lacroix, Ph.D.
Professor/Director
Research Laboratories in Sciences Applied to Food
Canadian Irradiation Centre
INRS-Institut Armand-Frappier
531 des Prairies blvd.
Laval city, Québec, Canada H7V 1B7
Monique.lacroix@iaf.inrs.ca
www.iaf.inrs.ca
Tel: 1 450 687 5010 ext 4489