monique lacroix, ph.d. professor research laboratories in sciences applied to food inrs-institut...
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Monique Lacroix, Ph.D.Professor
Research Laboratories in Sciences Applied to FoodINRS-Institut Armand-Frappier
531 des Prairies blvd.Laval city, Québec, Canada H7V 1B7
Tel: 1 450 687 5010 ext 4489
©INRS, 2014
Development of active edible coating and biodegradable packaging for food
application
International Conference and Exhibition on Biopolymers and Bioplastics
August 11,2015, San Francisco, USA
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.
• 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
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
Edible coating: potential
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 BillionJapan: $80 Billion
Germany: $29 BillionFrance: $19 Billion
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
Driving in coating and packaging innovation
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.
CampylobacterE.coliSalmonellaListeria
Post-processing protection byActive 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 oxidationDelay microbial growth
Assure innocuity of foodsControl the respiration
Delay moisture migrationAbsorb CO2
Remove ethylene and aroma emittersAbsorb drip
Better protection of the food quality and reduce the waste level
• Rancidity• Chocolate firm• Fat bloom
Rejection by the consumer
Return the product to the producer
Example of edible coating:barrier properties
edible coating: transport limitation of unsaturated fatty acids
Oil
Chocolate almond
Diffusion of oil based on the addition of various polymers
ResultsResults
Milk proteins have high nutritional value
They are available in large amounts world-wide
They have been extensively investigated as edible coatings and films
Application against the browning of fresh fruits and vegetables
enzymatic browning Stabilizing the whiteness of the product
40
50
60
70
80
90
0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5
L*
temps (heures)
contrôle caséinate lactosérum L+C
Control
Coated
Edible coating: antioxydant properties
Storage time (days)
0 10 20 30 40
Con
tam
inat
ion
(%)
0
20
40
60
80
100
ControlBase Base+PLS
Application against the growth of molds on strawberries Protective barrier against moisture shelf life of strawberries
Edible coating:antimicrobial properties
Chitosan
NH2
O
OH
OHO
NH2
O
OH
OHO
O
OH
OHNH2
O
OH
OOH
O
CH3
ONH
Natural polysaccharides, the second most abundant after cellulose
Poor mechanical properties, lack of water resistance
High water permeability
High gases barriersIt 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 propertiesStabilization of active compounds in chitosan (encapsulation matrix)
According to Han et al. (2008)
Modified chitosan-based coating on strawberriesIn situ antimicrobial activity
3450-31503450-31503450-3150b) PLA-NCC-nisin filmb) PLA-NCC-nisin film
Evolution of the decay level (%) in antimicrobial coated strawberries during storage.
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
Modified chitosan-based coating on strawberriesIn situ antimicrobial activity
3450-31503450-31503450-3150b) PLA-NCC-nisin filmb) PLA-NCC-nisin film
Appearance of strawberries coated with modified chitosan-based formulation containing limonene and emulsifiers.
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
0 1 2 3 4 5 6
Non encapsulé
Formulation 1Formulation 2
Formulation 3Formulation 4
0%
20%
40%
60%
80%
100%
Temps (mois)
LAB• Protection during gastro
intestinal passage
encapsulation in polymer
Based on modified chitosan,
Modified alginate
pH 1.5 -2.5
10 6-10 7
10 9
polymerpolymer
BacteriaBacteria
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
Irradiation doses (KGy)
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
Lo
g N
/N0
-6
-5
-4
-3
-2
-1
0
Control (air)Coating (air)MAPMAP+Coating
0.061
0.083
0.102
0.110
Radiosensitization of E. coli on green bean samples as affected by coating formulation under various atmospheres
Irradiation doses (KGy)
0.0 0.5 1.0 1.5 2.0 2.5
Lo
g N
/N0
-6
-5
-4
-3
-2
-1
0
Control (air)MAPCoating (air)MAP+ Coating
0.202
0.295
0.332
0.383
Radiosensitization of S. Typhimurium on green bean samples as affected by coating formulation under various atmospheres
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
D10 values of selected pathogens and total microflora in broccoli florets coated with active coating
Day 1 Day 3 Day 5 Day 7 Day 9 Day 11 Day 13
Control 2.98Aa 3.03A
a 3.10ABa 3.14AB
a 3.18Ba 3.41C
a 3.95Da
MAP 3.02Aa 3.19A
a 3.05ABa 3.01ABa 2.80B
b 2.98ABb 3.01AB
b
Coating (air) 2.45ABb 2.15A
b 2.57Bb 1.40C
b 1.25Cc ND ND
Coating+MAP 2.64Ab 2.59AB
c 2.30Bb 1.66C
b 1.19Dc ND ND
γ (air) 1.71Ac 1.26B
d 1.18Bc ND ND ND ND
γ +MAP 1.62Acd 1.45B
e 1.19Cc ND ND ND ND
γ+coating (air) 1.30Ad 1.35A
de 1.25Ac ND ND ND ND
γ+coating+MAP ND ND ND ND ND ND ND
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
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).
Storage time (d)
0 5 10 15 20 25
Log
CF
U/g
0
1
2
3
4
5
6
7
8
0 kGy
1 kGy
2 kGy
Storage time (d)
0 5 10 15 20 25
log
CF
U/g
0
1
2
3
4
5
6
7
8
0 kGy
1 kGy
2 kGy
Bacterial population on refrigerated pizzas as affected by gamma irradiation and edible coating based
on milk proteins
Irradiation alone Irradiation + edible coating
C,3 days
1 kGy,12D
2 kGy, 14D
C,17D
1-2 kGy > 21 D
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.
0500000
1000000150000020000002500000300000035000004000000
0 8 16 32 64 92 128
Dose (kGy)
Flu
ore
scen
ce in
ten
sity
(a
.u)
Base
PEG
Sor
Man
Formation of bityrosine in calcium caseinate films as a function of irradiation dose
0
10
20
30
40
50
60
70
80
4 8 16 32 64 96 128Dose (kGy)
Weig
ht
yie
ld (
%)
Fraction of insoluble matter in function of the irradiation doseResults are expressed as the percentage in solid yield after soaking the
films 24 hours in water
Effect of crosslinked films based on milk proteins containing essential oils on
E.coli 0157:H7 growth on beef
2,0
2,2
2,4
2,6
2,8
3,0
3,2
3,4
3,6
3,8
4,0
0 2 4 6 8Temps (jour)
Lo
g U
FC
/CM
2
Beef without film
film with pepper
pepper + origano extract
Origano extract
ADFs: New generation of antimicrobial device
Trilayer film PCL/MC/PCL
CNC fillingin MC matrix
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 broccoliPercentage of total phenolics (TP) release from ADFs during storage
FTIR spectra of bioactive ADF internal layer in fingerprint area (1200-1800 cm-1) for the estimation of TP release (diffusion of volatiles).
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)
1600
1515
1265
Day 0
Day 2
Day 6
Day 13
ADFs on fresh broccoliPercentage of total phenolics (TP) release from ADFs during storage
TP release (%) from bioactive ADFs during storage, deduced from TP availability in films by Folin-Ciocalteu‘s method.
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)
ADFs on fresh broccoli
Microbiolgical analysis
Antimicrobial effect of trilayer ADFs on E. coli during storage of broccoli (12 days at 4°C).
Total inhibition of E. coli at day 12
Stronger effect of formulation A at day 4
ADFs on fresh broccoli
Microbiolgical analysis
Antimicrobial effect of trilayer ADFs on S. Typhimurium during storage of broccoli (12 days at 4°C).
Total inhibition of S. Typhimurium at day 7
Stronger antimicrobial efficiency against gram-negative bacteria
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 physico-chemical 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 FoodCanadian Irradiation Centre
INRS-Institut Armand-Frappier531 des Prairies blvd.
Laval city, Québec, Canada H7V [email protected]
www.iaf.inrs.caTel: 1 450 687 5010 ext 4489