monique lacroix, ph.d. professor research laboratories in sciences applied to food inrs-institut...

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

Monique.lacroix@iaf.inrs.cawww.iaf.inrs.ca

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 1B7Monique.lacroix@iaf.inrs.ca

www.iaf.inrs.caTel: 1 450 687 5010 ext 4489