1. A group of students at the Royal University of Phnom Penh developed environmentally friendly food packaging films using ethyl cellulose incorporated with pH indicator dyes. 2. The films were tested for properties like water absorption, color changes, and mechanical strength. Color changes indicated the films responded to changes in pH, showing potential as smart packaging to detect food deterioration. 3. Testing showed the dye-incorporated films had lower water absorption and responded mechanically when stretched, with the methyl orange film performing best. The films degraded safely and are a promising sustainable alternative to conventional plastic food packaging.

1. Royal University of Phnom Penh
Faculty of Engineering
Department of Bio-Engineering
Supervisor : Dr. Long Solida
Group members
1. Chhouklay Linna ( year 3)
2. Ven Sovannaroth (year 2)
3. Song Sursdey (year 2)
Food Packaging: Innovative concepts and Necessities
Environment friendly qualitatively responsive
ethyl cellulose films as smart food packaging
Topic:

2. I. Objective
II. Keywords
III. Introduction
IV. Materials and
Method
V. Results and
Discussion
VI. Conclusion
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Contents

3. Objective
-To develop an environmental friendly qualitatively
responsive film for food packaging with an emphasis on the
change in pH of the packed food staff. For this purpose, pH
responsive ethyl cellulose films have been developed by
incorporating azo indicators such as Methyl Red (MR) and
Methyl Orange (MO) by casting method.

4. Keywords
 Smart packaging: Refers to packaging systems used for foods,
drinks, pharmaceuticals, cosmetics and many other perishable
goods. It involves both active and intelligent functions that protect
the staffs from the inside of its packaging.
 pH sensing: is one of the most essential tools that’s typically used
for water measurements. This type of sensors is able to measure
the amount of alkalinity and acidity in water and other solution.
 Azo indicators: Chemical indicators, any substances that give a
visible sign usually by a color change such as Methyl Orange (MO)
and Methyl red (MR).
 Ethyl Cellulose (EC): is a derivative of cellulose in which some of
the hydroxyl groups on the repeating glucose units are converted
into ethyl ether groups. The number of ethyl groups can very
depending on the manufacture.
 Environmental friendly: Everything which is not harmful to
environment.
 Casting method: is a manufacturing process in which a liquid
materials is usually poured into a mold, which contains a hollow
cavity of the desired shape, and then allowed to solidify. Casting method

5.  Intrinsic and extrinsic influenced the shelf life of the
packaged food. To overcome the adverse effect of
these factors, many innovations in the food
packaging technologies have been increased over
the period of time.
 Food packaging has been a part of significant since the olden day; generally polymers are used to
packed foodstuff include polyolefin, substituted olefin, polyesters, polyamides, and polycarbonates
etc., but ending into garbage and are not environmental friendly.
Introduction

6. Introduction
 Criteria for intelligent packaging including time temperature indicator, freshness indicator, Oxygen
and Carbon dioxide indicators.
 The development of environment friendly qualitatively responsive film for the food packaging,
researchers studied about incorporating azo indicators such as Methyl Red (MR) and Methyl
Orange (MO) in ethyl cellulose by casting method. As Ethyl cellulose is biodegradable so the
resulted films is also biodegradable too.

7. Materials
Ethyl cellulose
#All the chemicals used were of AR grade and
were supplied by CDH(P) LTD., New Delhi
Ethoxy 48-
49.5%
Ethanol 99.9%
Polyethylene
glycol
Methyl orange
and Methyl
red 0.1%
Acetic acid

8. Method
Preparation of Ethyl Cellulose Films 3samples
Homogenized
20-25mins
2.5% w/v solution
of EC in ethanol
was prepared by
constant stirring at
100rpm
Polyethylene glycol
2.5% w/v solution
of EC in ethanol
was prepared by
constant stirring at
100rpm
20-25mins
Homogenized
Polyethylene
glycol and MR
0.1%
2.5% w/v solution
of EC in ethanol
was prepared by
constant stirring
at 100rpm
Homogenized
Polyethylene
glycol and MO
0.1%
20-25mins
Continued stirring
1-2mins
Continued stirring
1-2mins
Cast solution was
then gently
poured into a
Petridish
Cast solution was
then gently
poured into a
Petridish
Cast solution was
then gently
poured into a
Petridish
Continued stirring
1-2mins

9. Characterization of Ethyl Cellulose Films (EC)
• Yield of EC
• Water Absorption Capacity( in weight % age )
• Mechanical properties
• Moisture content(%)
• Soluble matter (%)
• color parameters of EC
• Microstructural

10. Characterization of Ethyl Cellulose Films (EC)
Mechanical properties
Yield of EC ( in % age )
Water Absorption Capacity( in weight % age )
Moisture content(%)
Soluble matter (%)

11. Color parameters of EC
L* lightness of colours from 0 (dark) to 100 (light)
a* is the grade of greenness/redness (negative a* is green and positive a* is red)
b* is the grade of blueness//yellowness (negative b* is blue and positive b* is yellow)
Chroma meter CR 400
colorimeter( Japan )
The colorimetric measurements CIE L* a* b*

12. Microstructural SEM
Electron microscope(S-700N)
Sample without azo indicator
Sample with MR
Sample with MO
Gold sputtered
Film samples add P2O2
Testing
Liquid nitrogen

13. Result and Discussion
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3.1. Visual Inspection
3.2. Yield of Ethyl Cellulose Film
• There is slight increase in the yield of the EC film on the addition of the indicator
• Cellulose film incorporated with MR indicator i.e., 5.65%, whereas the yield of ethyl
cellulose films incorporated with MO indicator was observed as 4.69%
• Compared to PEC(Polyelectrolyte complex), pH was raised from 3 to 5.5 which they
share similar result

14. Result and Discussion
3.3. Water Absorption Capacity

15. Result and Discussion
3.4. Colorimetric Analysis

16. Result and Discussion
3.5. Scanning Electron Microscopy (SEM)

17. Result and Discussion
3.6. Mechanical Properties
Limit Load 2Kg
Tensile strength, (EAB%), (E)testing on micro-UTM
Necking
deformation

18. Result and Discussion
3.6. Mechanical Properties
This result was reporting by plotting stress strain curve

19. 3.7. Soluble matter (SM)
 The ethyl cellulose film with or without indicators immersed in distilled water for 24
hours, showed no swelling and maintained their structure well. The soluble matter
among different pH responsive ethyl cellulose films was more for the EC-MR film i.e.,
approximately 77% and about 60% for the EC-MO film, However the soluble matter for
ethyl cellulose film without indicator showed the total soluble matter about 62.50%.
3.8. Moisture Contain (MC)
 Ethyl Cellulose film with MO showed approximately 10% lower moisture content as
compared with the ethyl cellulose film without indicator, while the ethyl cellulose film
with MR showed a great increase in the moisture content.

20. Conclusion
 The resulted films were tested for their water absorption capacity, colorimetry
and mechanical behavior.
 CIELAB detected and correlated the color variations at different pH. The pH
responsive films evidently responded well with the change in pH and are
expected to qualitatively due to acid production in the food staff under real
situation, and might help to determine the deterioration of packaged food
without even opening.
 As, the azo linkage may easily undergo enzymatic break down in liver and
kidney and the aromatic amines, so produced are excreted in urine, so there
is no major concern to evaluate the food safety of these azo dyes
incorporated in ethyl cellulose films.
 The addition of azo indicators decreased the water absorption capacity of the
film up to 10%. Among all films tested, the ethyl cellulose film incorporated
with MO indicator had shown a better response when tested by a micro UTM.
The peak load was observed at around 2.7N.

21. Reference
- Yadav, N. & Kaur, R. (2019). Material Express. Environment friendly qualitatively responsive ethyl cellulose
films as smart food packaging, 9(2019), 792-800. DOI: 10.1166/mex.2019.1559