D
OXYGEN AND CARBON DIOXIDE TRANSMISSION RATES OF LOCALLY AVAILABLE POLYETHYLENE FILMS FOR MODIFIED ATMOSPHERE PACKAGING
IN THE PHILIPPINES
IBN XAVIER REYES MALILAY
SUBMITTED TO
THE FACULTY OF THE AGRICULTURAL AND BIO-PROCESS DIVISION INSTITUTE OF AGRICULTURAL ENGINEERING
COLLEGE OF ENGINEERING AND AGRO-INDUSTRIAL TECHNOLOGY UNIVERSITY OF THE PHILIPPINES LOS BAÑOS
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF
BACHELOR OF SCIENCE IN AGRICULTURAL ENGINEERING (Specialized in Agricultural and Bio-Process Engineering)
TABLE OF CONTENTS
PAGE
TITLE PAGE i
ACCEPTANCE SHEET ii
BIOGRAPHICAL SKETCH iii
ACKNOWLEDGEMENT iv
TABLE OF CONTENTS ix
LIST OF FIGURES xii
LIST OF TABLES xiv
ABSTRACT xv
I. INTRODUCTION
A. Significance of the Study 1
B. Objectives of the Study 2
C. Scope and Limitations of the Study 3
D. Date and Place of the Study 4
II. REVIEW OF RELATED LITERATURE
A. Overview on Modified Atmosphere Packaging 5
B. Basic Concepts on Modified Atmosphere Packaging C. Modelling of Modified Atmosphere Packaging
7
1. Product Physiology
2. Gas Transmission Through Modified Atmosphere Packaging Films 11
3. Temperature Effects 13
D. Type of Modified Atmosphere Packaging Films 1. Continuous Films
2. Perforated Films 14
3. Smart Films 15
III. METHODOLOGY
A. Materials and Methods Used 16
B. Methodology
1. Gas Diffusion Chamber
2. Polyethylene Films 20
3. Methods of test 21
a. Procedures for Flushing of Gas Mix
b. Gas Analysis 25
c. Gas Transmission Rate Determination 26 i. Effective Area of Diffusion
ii. Film Thickness Determination 29
iii. Volume computation
iv. Gas Transmission Rate Determination 30 d. Determination of Temperature Effects 32 4. Statistical Analysis
33
5. Product Matching
IV. RESULTS AND DISCUSSIONS A. Pressure and Leakage Correction
35
B. Gas Transmission rate 36
1. Continuous Films
2. Perforated Films 44
C. Temperature Effects 49
D. Product Matching 54
V. SUMMARY AND CONCLUSION 55
VI. RECOMMENDATIONS 57
VII. REFERENCES 58
VIII. APPENDICES 60
LIST OF FIGURES
FIGURE PAGE
1 Modified Atmosphere Packaging Model 6
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Schematic Diagram of the Geometry of the Cylindrical Hole in the Packaging Film
Gas Diffusion Chamber
Parts of the Gas Diffusion Chamber
DOW CORNING® High Vacuum Grease
3mm x 175mm Diameter O-ring
3” C-clamp
Polyethylene Film Samples; (a) PE50 (b) PE40 (c) PE25
19G x 1 ½” (1.10 x 38mm) Needle
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Nitrox™ Nitrogen Generator
Gas Mix Tank
Set-up of Flushing of Gas Mix
Cold Room
Gas Diffusion Chamber Set-up
PBI Dansensor CheckMate II Gas Analyzer
Super® Black RTV Silicone Gasket Maker
Microscope with Ocular Micrometer
Magnified View of the Perforation
Thickness Gauge
Gas Concentration Versus Time of PE25-C and PE25-P at Different Temperatures
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25
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Gas Concentration Versus Time of PE40-C and PE40-P at Different Temperatures
Gas Concentration Versus Time of PE50-C and PE50-P at Different Temperatures
Representative Gas Diffusion Chamber Plot of ln(ΔP/ΔP˚) Versus Time for O2TR and CO2TR of PE25, PE40 and PE50
Temperature and O2TR-C Relationship of Different Polyethylene Film Thickness
Temperature and CO2TR-C Relationship of Different Polyethylene Film Thickness
O2TR-C and O2TR-P Versus Temperature
CO2TR-C and CO2TR-P Versus Temperature
Arhenius Plot of ln O2TR-C Versus 1/T
Arhenius Plot of ln CO2TR-C Versus 1/T
Arhenius Plot of ln O2TR-P Versus 1/T
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Arhenius Plot of ln CO2TR-P Versus 1/T
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LIST OF TABLES
TABLE PAGE
1
2
3
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Potential Advantages and Disadvantages of Modified Atmosphere Packaging
Potential Advantages and Disadvantages of Different Gases Used in Modified Atmosphere Packaging
Recommended Storage Conditions for Some Respiring and Non-respiring Food Products
Experimental and Published Gas Transmission Rates of Continuous Polyethylene Films at Different Temperatures
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42
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Apparent Gas Transmission Rates of Perforated Polyethylene Films at Different Temperatures
Estimated Gas Transmission Rates Through the Perforation Alone at Different Temperatures
Experimental and Published Activation Energies (KJ/mol) at Continuous PE Film Samples
Computed Activation Energies (KJ/mol) of Perforated PE Film Samples
ANOVA of Dependent Parameters as Affected by the Independent Variables
ANOVA of Independent Variables on the Five Dependent Parameters
Summary of O2TR and CO2TR of the PE Film at 13˚C Along with the Amount of O2 and CO2 it can Apply to the Commodity
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50
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MALILAY, IBN XAVIER REYES, College of Engineering and Agro-Industrial Technology, University of the Philippines Los Baños, APRIL 2009. Oxygen and Carbon dioxide Transmission Rates of Locally Available Polyethylene Films for Modified Atmosphere Packaging in the Philippines
Adviser: Dr. Kevin F. Yaptenco
ABSTRACT
Polyethylene (PE) film samples with nominal thickness of 25, 40 and 50 µm (PE25, PE40 and PE50 respectively) were tested for oxygen and carbon dioxide transmission rates (O2TR and CO2TR respectively) using fabricated gas diffusion chamber under 5˚C, 10˚C and ambient temperatures. Oxygen and carbon dioxide concentrations for each chamber were monitored for 30 hours using the method described by Moyls et al. (Moyls, I., Hocking, R., Beveridge, T. and Timbers, G., 1992.
Transactions of the ASAE 35(4): July-August 1992). O2TR-C and CO2TR-C are highest in PE25 at ambient temperature (25.7˚C) having values of 13138 ± 2.5% and 54322 ± 2.1%
mL/m2day respectively and lowest in PE50 at 5˚C with values of 1907 ± 5% and 8027 ± 14.8%. In general, as film thickness decreased O2TR and CO2TR increased.
The PE samples followed Arhenius kinetics with activation energy highest in PE50 with 33089 kJ/mol K and 30477 kJ/mol K for O2 and CO2 respectively and lowest in PE25 with 23332 kJ/mol K and 22478 kJ/mol K for O2 and CO2 respectively.
The effect of the perforation and the magnitude of its effect to the gas transmission rates for PE25, PE40 and PE50 at different temperatures were also determined. The addition of perforation to PE film increased the O2TR and CO2TR by 42134 to 56142 mL/m2day for O2TR and 22872 to 44664 mL/m2day CO2TR.
The diameter of the perforation was found to be too large (256 µm) rendering the effects of film thickness and temperatures to O2TR and CO2TR insignificant (R2 = 0.08 and 0.06 for O2TR and CO2TR respectively).
