Its about biodegradable polymers, their classification, application of bio-polymer in food packaging, nanotechnoogy etc

1. BIO-DEGRADABLE FILMS FOR FOOD
PACKAGING
AGRICULTURAL AND FOOD ENGINEERING DEPARTMENT
INDIAN INSTITUTE OF TECHNOLOGY, KHARAGPUR
DEEPAK ADHIKARI
PRESENTED BY

2. OBJECTIVE OF SEMINAR
 To understand the importance of development of biodegradable
films
 To illustrate the biodegradable films used in food packaging

3. ROADMAP
 Introduction
 Biodegradable polymer
 Classification of biodegradable polymers
 Biodegradation process
 Source of Biodegradable polymers
 Application of biopolymers in food packaging
 Advantages and disadvantages of biodegradable polymer
 Nanotechnology used in food packaging
 Case study
 Conclusion
 References

4. INTRODUCTION
 Most of today’s synthetic polymers are produced from
petrochemicals and are not biodegradable.
 Persistent polymers generate significant sources of
environmental pollution, harming wildlife when they are
dispersed in nature.
E.g: Disposal of non-degradable plastic bags adversely
affects sea-life

5. BIODEGRADABLE POLYMERS
Biodegradable polymers are a specific type of polymer that
breaks down after its intended purpose to result in natural
byproducts such as gases (CO2, N2), water, biomass, and
inorganic salts.

6. STRUCTURE OF BIODEGRADABLE POLYMER

7. BIODEGRADATION PROCESS
Biodegradation is the chemical dissolution of materials by
bacteria or other biological means.
Biodegradable simply means to be consumed by
microorganisms and return to compounds found in nature

8. STEP – I
 The long polymer molecules are reduced to shorter and shorter
lengths and undergo oxidation (oxygen groups attach
themselves to the polymer molecules).
 This process is triggered by heat , UV light and mechanical
stress .
 Oxidation causes the molecules to become hydrophilic (water-
attracting) and small enough to be ingestible by micro-
organisms, setting the stage for biodegradation to begin.

9. Step-2
 Biodegradation occurs in the presence of moisture and micro-
organisms typically found in the environment.
 The plastic material is completely broken down into the
residual products of the biodegradation process.
Step-3
 As micro-organisms consume the degraded plastic, carbon
dioxide, water, and biomass are produced and returned to
nature by way of the biocycle.

11. Approximated time for compounds to biodegrade in a marine
environment
Product Time to Biodegrade
Apple core 1–2 months
General paper 1–3 months
Paper towel 2–4 weeks
Cardboard box 2 months
Cotton cloth 5 months
Plastic coated milk carton 5 years
Wax coated milk carton 3 months
Tin cans 50–100 years
Aluminium cans 150–200 years
Glass bottles Undetermined (forever)
Plastic bags 10–20 years
Soft plastic (bottle) 100 years
Hard plastic (bottle cap) 400 years

12. OXO-BIODEGRADATION
It is the degradation resulting from oxidative and cell -
mediated phenomena, either simultaneously or successively.
It is the two-stage process-
Stage 1(Abiotic process)- Carbon backbone of the polymer is
oxidized resulting in the formation of smaller molecular
fragments

13. Stage 2 - The biodegradation of the oxidation products by
microorganisms (bacteria, fungi and algae) that consume the
oxidized carbon backbone fragments to form CO2,H2O and
biomass
“Initial abiotic oxidation is an important stage as it determines
the rate of the entire process”

14. SOURCE OF BIODEGRADABLE
POLYMERS
 Polysaccharides
 Starches
 Wheat
 Potatoes
 Maize
 Ligno-cellose product
 Wood
 Straws
 Others
 Pectins
 Gums

15. ANAEROBIC DIGESTION

16. 1. Biodegradable polymers obtained by chemical synthesis
 Polyglycolic acid
 Polylactic acid
 Polycaprolactone
 Polyvinyl alcohol
CATEGORIES

17. 2.Biodegradable polymers produced through fermentation by
microorganisms :
 Polyesters
 Neutral polysaccharides
3.Biodegradable polymers from chemically modified natural
product :
 Starch
 Cellulose

18. APPLICATION IN FOOD
PACKAGING
 Edible coating
 Paper boards
 Egg trays
 Carry bags
 Wrapping films
 Containers

19. ADVANTAGES AND DISADVANTAGES OF
BIOPOLYMER :
Raw material Advantages Disadvantages Reference
Whey
protein
isolate
Desirable film
forming
properties
Good oxygen
barrier
low tensile
strength
high water
vapour
permeability
Kadham et
al., (2013)
Gluten Low cost
Good oxygen
barrier
Good film-
forming
properties
High
sensitivity to
moisture and
brittle
Peelman et
al., (2013)

20. Raw
material
Advantages Disadvantages Reference
Zein  Good film
forming
properties
Good tensile
and moisture
barrier properties
Brittle Pol et al.,
(2002).
Cho et al.,
(2010).
Chitosan Antimicrobial
and antifungal
activity
Good
mechanical
properties
Low oxygen
and carbon
dioxide
High water
sensitivity
Peelman et al.,
(2013).

21. Raw material Advantages Disadvantages Reference
Soy protein
isolate
Excellent
film forming
ability
Low cost
Barrier
properties
against oxygen
permeation
Poor
mechanical
properties
High water
sensitivity
Pol et al.,
(2002).
Cao et al.,
(2007)
Cho et al.,
(2010).

22. NANOMATERIALS USED IN FOOD PACKAGING
 Nanotechnology can be used in plastic food packaging to make
it stronger, lighter or perform better.
 Antimicrobials such as nanoparticles of silver or titanium
dioxide can be used in packaging to prevent spoilage of foods.

23.  Introduction of nanoparticles into packaging to block oxygen,
carbon dioxide and moisture from reaching the food, and also
aids in preventing spoilage.

24. CASE STUDY
“Use of biodegradable film for cut beef steaks packaging”

25.  Title: Use of biodegradable film for cut beef steaks packaging
 Author: M. Cannarsia,, A. Baiano, R. Marino, M. Sinigaglia
and M.A. Del Nobile
 Journal: Meat Science 70 (2005) 259-265

26. Objective:
To check the possibility of replacing PVC film with
biodegradable polymers in order to preserve the characteristic
meat colour as well as control the microbial contamination.

27.  Meat was obtained from ten organically farmed Podolian
young bulls.
 Animals were slaughtered at 16–18 months of age. Mean
slaughter weight was 476 kg ± 22.23 kg
 Dressed carcasses were split into two sides and chilled for 48 h
at 1–3ºC, after that each side was divided in hind and fore
quarter and each quarter was jointed into different anatomical
regions.

28.  The semimembranosus muscle (meat) was chosen as
representing muscles of greatest mass and economic value.
 All the removed sections were vacuum-packaged and aged at
4ºC until 18 days post-mortem
 Meat (semimembranosus muscle) was removed from the ten
carcasses 18 days post-mortem and steaks (1cm thick, 100 g
weight) were cut.

29. Samples were individually placed on polystyrene trays and
hermetically packaged with the following three films:
 Biodegradable polymeric film
 Biodegradable polyesters
 Polyvinyl chloride film(PVC)

30. Mathematical model:
 Gompertz equation
Where,
A is the maximum microbial growth attained at the stationary
phase
µ max is the maximum growth rate
ʎ is the lag time
cfu max is the cell load allowed for consumer acceptability
S.L is the shelf life (the time required to reach cfu max
t is time

31. RESULTS
Film Thickness(µm) Pw(g cm cm-2 s1 atm-1)
Polymeric film 64 1.53×10-8 ± 4.84×10-10
Polyesters 51 4.30×10-9 ± 3.29×10-10
PVC 12 3.75×10-9 ±1.30×10-10
Table1: Water permeability data at 10ºCTable1: Water permeability data at 10ºC
Infrared sensor technique

32. Type of film Shelf
life(days)
PVC 2.41±0.12
Polymeric
film
2.13±0.11
Polyesters 2.16±0.11
Type of film Shelf
life(days)
PVC 1.88±0.01
Polymeric film 1.25±0.01
Polyesters 1.35±0.01
Table2: Shelf life of beef
sample stored at 4°C
Table3: Shelf life of beef
sample stored at 15°C

33. CONCLUSION
 The investigated biodegradable films could be advantageously
used to replace PVC films in packaging fresh processed meat,
reducing in this way the environmental impact of polymeric
films
 The use of biodegradable polymer reduces the environmental
impact of non-degradable plastic
 Incorporation of nanoparticles is an excellent way to improve
the performance of biobased films.

34. THE FUTURE OF FOOD PACKAGING
“Compostable biopolymer plastics have the
potential to gain a significant percentage of the
plastic food-packaging market share in the next 10
Years”

35. REFRENCES
 Averous, L., and Pollet, E. 2012. Biodegradable polymer.
Environmental silicate nano-biocpmposites.
 Cao, N., Yuhua, F. and Junhuin, H. preparation and physical properties
of soy protein isolate and gelatin composite films. Food
hydroclloids. 21. 1153-1162
 Cho, Y.S., Lee, Y. S. and Rhee, C. 2010, Edible oxygen barrier
bilayerfilm pouches from corn zein and soy protein isolate for
olive oil packaging, LWT – Food Sci. and Technol., 43: 1234-1239.
 Flieger, M., Kantorova, M., Prell, A., Rezanka, T. and vortuba. 2003.
biodegradable plastics from renewable sources. Folia microbiol.
48(1), 27-44
 Heap, B. 2009. Preface. Philosophical Transactions of the Royal
Society B: Biological Sciences . 364: 1971-1971.

36.  Kadam, M. D., Thunga, M., Wang, S., Kessler, R. M., Grewell, D.,
Lamsal, B. and Yu, C. 2013, Preparation and characterization of
whey protein isolate films reinforced with porous silica coated
titaniam nanoparticles, J. of Food Engng., 117 (1): 133-140.
 Kuorwel, K. K., Cran, J.M., Sonneveld, K., MiltZ, J. and Bigger, W.S.
2011, Antimicrobial Activity of Biodegrdable polysaccharide and
Protein- Based Films Containing Active Agents. Journal of Food
Science, 76, 90-106.
 Liu, L. 2006. Bioplastics in Food Packaging: Innovative Technologies
for Biodegradable Packaging
 Lam, D. 2010. packaging application using Nanotechnology. San jose
state university.

37.  Peelman, N., Ragaert, P,. Meulenaer, D. B., Adons, D., Peeters, R.,
Cardon, L., Impe, V. F., and Devlieghere, F. 2013. Application of
bioplastic for food packaging. Trends in Food Science &
Technology. 1-14.
 Pol, H., Dwason, P., Action, J. and Ogale, A. 2002. soy protein
isolate/corn-zein laminated films: transported and mechanical
properties. Food engineering and physical properties. 67(1).
 Rhim, W. J., Lee, H. J. and Perry K.W. 2007. Swiss society of food
science and technology. 40: 232-238.
 Sorrentino, A., Gorrasi, G. and Vittoria, V. 2007, Potential perspectives
of bio-nanocomposites for food packaging applications, Trends in
Food Sci. and Technol., 18 (2): 84-95.