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 © 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 industries 5 Millions employees Food Packaging represent 65% of the market USA: $100 Billion Japan: $80 Billion Germany: $29 Billion France: $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. Campylobacter E.coli Salmonella Listeria

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 CO 2 Remove ethylene and aroma emitters Absorb 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 Chocolatealmond

Diffusion of oil based on the addition of various polymers Results

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 Control Coated Edible coating: antioxydant properties

Application against the growth of molds on strawberries  Protective barrier against moisture   shelf life of strawberries Edible coating:antimicrobial properties

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

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)

Modified chitosan-based coating on strawberries In situ antimicrobial activity b) 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 strawberries In situ antimicrobial activity b) 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 º C and 100% RH after encapsulation with modified chitosan

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

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

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

BacteriaControlOA/LAB metabolites OA/FEOA/FE/SMOA/SE L. monocytogenes E. coli * 0.16* S. Typhimurium *0.29*0.28*0.25* Aerobic flora * 0.32* 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 D 10 values of selected pathogens and total microflora in broccoli florets coated with active coating

Day 1Day 3Day 5Day 7Day 9Day 11Day 13 Control2.98 A a 3.03 A a 3.10 AB a 3.14 AB a 3.18 B a 3.41 C a 3.95 D a MAP3.02 A a 3.19 A a 3.05 AB a 3.01 ABa 2.80 B b 2.98 AB b 3.01 AB b Coating (air)2.45 AB b 2.15 A b 2.57 B b 1.40 C b 1.25 C c ND Coating+MAP2.64 A b 2.59 AB c 2.30 B b 1.66 C b 1.19 D c ND γ (air)1.71 A c 1.26 B d 1.18 B c ND γ +MAP1.62 A cd 1.45 B e 1.19 C c ND γ+coating (air)1.30 A d 1.35 A de 1.25 A c ND γ+coating+MAPND 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% O 2, 30% CO 2, and 10% N 2 ).

0 kGy 1 kGy 2 kGy 0 kGy 1 kGy 2 kGy Bacterial population on refrigerated pizzas as affected by gamma irradiation and edible coating based on milk proteins Irradiation aloneIrradiation + 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.

Formation of bityrosine in calcium caseinate films as a function of irradiation dose

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

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 Origano extract

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

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 FTIR spectra of bioactive ADF internal layer in fingerprint area ( 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 )  Day 0  Day 2  Day 6  Day 13

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)

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 Food Canadian Irradiation Centre INRS-Institut Armand-Frappier 531 des Prairies blvd. Laval city, Québec, Canada H7V 1B7 Tel: ext 4489