1. 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
Tel: ext 4489
International Conference and Exhibition on 
Biopolymers and Bioplastics 
August 11,2015, San Francisco, USA
©INRS, 2014

2. 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.

3. 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

4. Biobased packaging
Packaging containing raw materials originating from agricultural sources produced from renewable, biological raw materials such as starch, cellulose and
bio-derived monomers

5. Global market of packaging
$ 417 Billion industries 5 Millions employees Food Packaging represent 65% of the market USA: $100 Billion Japan: $80 Billion Germany: $29 Billion France: $19 Billion

6. 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
Shelf life extension needed
Cost-efficiency

7. Post-process contamination
66% of the post-process contamination is caused by Product mishandling Faulty packaging

8. 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

9. 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

10. 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).

11. Active Coating and Packaging
Active coating and packaging allow interaction with food products and the environment and play a dynamic role
in food protection
The demand for minimally processed food and ready to eat food and the distribution from the centralized processing pose major problems. Recent food borne microbial out-brakes are driving a search for innovative ways to inhibit the growth of bacteria in the food while maintaining quality, freshness and safety. One option is to develop food packaging where natural antimicrobials will be incorporated. Natural antimicrobials can be included in the films (bacteriocins, essential oils from spices, organic acids).
Active packaging allows to interact with food product and the environment and play a dynamic role in food protection
Active packaging have led to advances in many areas including delayed oxydation, control the respiration of fruits for example, control the growth rate of bacteria, and moisture migration.
Other active packaging can absorb CO2, odors, Remove ethylene and aroma emitters, Absorb drip (ex: meat industry)
However, research is needed because the addition of antimicrobial compounds in the films can impart the color and opacity of the films, decrease the mechanical and barrier properties of the films, and may alter heat sealing strength, adhesion and printing properties.

12. 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
Active packaging
Active packaging have led to advances in many areas including delayed oxydation, control the respiration of fruits for example, control the growth rate of bacteria, and moisture migration.
Other active packaging can absorb CO2, odors, Remove ethylene and aroma emitters, Absorb drip (ex: meat industry)

13. Example of edible coating:barrier properties
Rancidity
Chocolate  firm
Fat bloom
Rejection by the consumer
Return the product to the producer
We have here an example of an application that we have developped for a company where this company was looking to avoid the problematic of rancidification of chocolat, to improve the shelflife and the quality of its products.
Rancidification is the hydrolysis and/or autooxidation of fats into short-chain aldehydes of ketones which result in undesirable odors or flavors.
In the chocolate the firmness can also be affected

14. edible coating: transport limitation of unsaturated fatty acids
Chocolate
almond
Oil
DEVRAIS-JE ENLEVER CETTE DIAPO??
This kind of problem can also appears in almond cover of chocolate where the oil of the almond will migrate/diffuse to the surface

15. Diffusion of oil based on the addition of various polymers
Results
Diffusion of oil based on the addition of various polymers

16. Milk proteins have high nutritional value
They are available in large amounts world-wide
They have been extensively investigated as edible coatings and films

17. Edible coating: antioxydant properties
Application against the browning of fresh fruits and vegetables
 enzymatic browning
Stabilizing the whiteness of the product
Control
Coated
Edible coatings can be applied on food surfaces as a thin layer edible film. Edible coatings can potentially extend the shelf life and improve the quality of food by the control of mass transfer, moisture and oil diffusion, gas permeability (O2, CO2), and flavor and aroma losses and by maintaining mechanical, rheological characteristics, color and appearance of foods.
Edible film as a solid sheet can be applied between food components or on the surface of the food system in order to inhibit migration moisture, oxygen, CO2, aromas and lipids. Edible films with adequate mechanical properties could also serve as edible packaging for selected foods. The selected proteins are originated from animal and plant sources consisting of caseins, whey proteins, collagen and gelatin, plasma proteins, myofibrillar proteins, egg white proteins, soy protein, wheat gluten and zein.

18. Edible coating:antimicrobial properties
Application against the growth of molds on strawberries
Protective barrier against moisture
 shelf life of strawberries
Another example of bio-coating to protect the emergence of moisture on strawberries
Base:
Base+PLS:

19. Chitosan
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

20. 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)

21. Modified chitosan-based coating on strawberries
b) PLA-NCC-nisin film
b) PLA-NCC-nisin film
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.

22. Modified chitosan-based coating on strawberries
b) PLA-NCC-nisin film
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.

23. Encapsulation for the preservation of Nutrients and functional products using modified chitosan

24. Retention of -caroten (%) during storage at 45 ºC and 100% RH after encapsulation with modified chitosan

25. LAB Protection during gastro intestinal passage
 encapsulation in polymer
Based on modified chitosan,
Modified alginate pH 
10 9
Bacteria
polymer

26. Viability of L. rhamnosus RW-9595M
* * *
* *
* * * *
(FC: Free BAL; NA: native alg.; SA: modified alg. ;
SC: modified chitosan; PA modified alg.).

27. The use of edible coating in combined treatment
to increase the antimicrobial property

28. Coating application of modified chitosan-based coating on ready to eat vegetables
Natural compounds have been formulated into coating to evaluate their efficiency in enhancing the shelf life and eliminating pathogens in brocoli
Coating formulations containing active compounds at concentration that do not affect the sensorial properties were sprayed on the surface of precutted brocoli before irradiation treatment

29. Radiosensitization of E
Radiosensitization of E. coli on green bean samples as affected by coating formulation under various atmospheres
Radiosensitization of S. Typhimurium on green bean samples as affected by coating formulation under various atmospheres

30. 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
E. coli
0.38
0.2*
0.16*
0.24
0.23
S. Typhimurium
0.50
0.29*
0.28*
0.25*
Aerobic flora
0.57
0.36*
0.32*
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

31. on population of E. coli on green beans samples during storage at 4 °C
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
Coating+MAP
2.64Ab
2.59ABc
2.30Bb
1.66Cb
1.19Dc
γ (air)
1.71Ac
1.26Bd
1.18Bc
γ +MAP
1.62Acd
1.45Be
1.19Cc
γ+coating (air)
1.30Ad
1.35Ade
1.25Ac
γ+coating+MAP
The deposition of the bioactive coating on green bean samples caused an immediate reduction in E. coli population, which reached the value of 2.45 log CFU/g already on day 1 of storage. After 7 days of storage, E. coli population on coated samples was significantly lower (of about 1.7 log CFU/g) than in control samples at the same day. Remarkably, after 11 days of storage there were no detectable bacteria on coated samples, highlighting the strong bactericidal effect of the developed coating formulation, based on MC containing CN.
The use of combined treatment of gamma irradiation and MAP did not significantly affect the effectiveness of gamma irradiation treatment alone: samples treated with gamma irradiation under MAP showed an E. coli population of 1.62 log CFU/g on day 1 of storage, and no detectable bacteria after 7 days of storage. Therefore, no significant difference can be noticed between irradiated samples packaged under air and irradiated samples packaged under MAP.
The combined treatment of gamma irradiation and bioactive coating reduced E. coli population to 1.3 log CFU/g on day 1 of storage, with a significant reduction of 1.7 log CFU/g, as compared to control samples. This combined treatment also showed a strong residual antimicrobial effect, with no detectable bacteria after 7 days of refrigerated storage. The combined treatment of on green bean samples with gamma irradiation, bioactive coating and MAP exhibited the strongest antimicrobial effect against E. coli, with no detectable bacteria over the entire storage period.
The combined treatment of MAP and bioactive coating showed a significant 1.5 log CFU/g reduction of E. coli population after 7 days of storage, as compared to control samples, with no detectable bacteria after 11 days of storage. Green bean samples treated with gamma irradiation doses of 0.25 kGy showed an E. coli population of 1.71 log CFU/g on day 1 of storage, with a significant reduction of 1.27 log CFU/g, as compared to control samples. Gamma irradiation treatment showed a strong residual antimicrobial effect already after 5 days of storage, with a microbial load reduction of 2 log CFU/g as compared to control samples, while after 7 days of refrigerated storage there were no detectable bacteria on treated samples.
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).

32. Bacterial population on refrigerated pizzas as
affected by gamma irradiation and edible coating based
on milk proteins
0 kGy
1 kGy
2 kGy
0 kGy
1 kGy
2 kGy
C,3 days
2 kGy, 14D
1-2 kGy > 21 D
1 kGy,12D
C,17D
1 kGy = shelf life extension of 9 days (from 3 to 12)
1 kGy = shelf life extension of 11 days (from 3 to 14)
Coating + irradiation 1 kGy = shelf life extension of 18 days (from 3 to 21)
Coating without irradiation shelf life extension of 14 days (from 3 to 17)
Coating + irradiation at 2 kGy = shelf life extension more than 18 days (from 3 to > 21)
Irradiation alone
Irradiation + edible coating

33. 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.

34. Formation of bityrosine in calcium caseinate films
as a function of irradiation dose
Bi-tyrosine was produced during irradiation and the amount is directly related to the dose of irradiation.

35. 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
Films were immersed in boiled water for 30 minutes and then dried in oven for 7 days at 45’C to determine the insolyble matter.
An increase of the recuperation of the films was observed by increasing the dose of irradiation.
70% of recuperation was observed in films containing casein + whey , however 88% of recuperation was observed for films based on casein only.

36. Effect of crosslinked films based on milk proteins containing essential oils on E.coli 0157:H7 growth on beef
Beef without film
film with pepper
pepper + origano extract
---Films containing Oregano based films was evaluated for their antimicrobial properties on meat. Pimento based films was also added to the films for their antimicrobial properties but also for their high antioxidant activities.
---The growth of E.coli was evaluated during storage. Results showed that oregano based films was THE MOST EFFECTIVE AGAINST the growth of E.coli and were able to produce a 1.12 LOG REDUCTION OF E. COLI O157:H7 LEVEL on beef during storage.
Origano extract

37. ADFs: New generation of antimicrobial device
Trilayer film PCL/MC/PCL
CNC filling
in 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

38. 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).

39. ADFs on fresh broccoli
Percentage of total phenolics (TP) release from ADFs during storage
FTIR spectra of bioactive ADF internal layer in fingerprint area ( cm-1) for the estimation of TP release (diffusion of volatiles).
1600
1515
1265
 Day 0
 Day 2
 Day 6
 Day 13
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 cm-1)
Ester antisym stretching (1265 cm-1)

40. ADFs on fresh broccoli
Percentage 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)

41. 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

42. 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

43. .
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

44. .
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.

45. 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

46. Research Laboratories in Sciences Applied to Food
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
Tel: ext 4489