1. www.agroparistech.fr www.ul.edu.lb
Study of polypropylene-polylactide / olive oil interaction using 3D front face fluorescence coupled with independent components analysis (ICA)
M. El Rakwe1,3 A. Kassouf1,2,3 J. Maalouly1 V. Ducruet2 G. Lassoued Ben miled4 D.N. Rutledge3
1 ER004 “Lebanese Food Packaging”, Faculty of Sciences II, Lebanese University, Jdeideth El Matn, Fanar, Lebanon.
2 INRA, UMR 1145 Ingénierie Procédés Aliments, 1 Avenue des Olympiades, Massy, France.
3 AgroParisTech, UMR 1145 Ingénierie Procédés Aliments, 16 rue Claude Bernard, Paris, France.
4 ISSBAT, Tunis El Manar University, Tunis, Tunisie.
Introduction
Results and discussion
Olive oil is a fundamental and indispensable food product in the Mediterranean diet due to its valuable aroma, taste and nutritional properties. Similar to other foodstuffs, produced in a limited period of time but consumed throughout the year, olive oil must be stored [1]. Commonly, olive oil is packaged in glass and metallic (tin-coated steel) containers. Nowadays, plastics are starting to be widely used for olive oil packaging due to their flexibility, variability in size and shape, light weight, etc. Among thermoplastics, polypropylene (PP) is used for its good resistance to fatty foodstuffs [2]. Polylactide (PLA), a new bio-based polymer is gaining worldwide attention and research must be done in order to enlarge its applications. However, the inertia of a package is rarely complete, which may lead to deteriorations in the safety and quality of the food [3].
The aim of this work is to study the interaction of PP containers and PLA trays with commercial olive oil, under accelerated aging conditions. The analytical methodology adopted combines 3D front face fluorescence spectra with independent components analysis (ICA).
After applying ICA by block, 5 ICs were selected for the data matrix of PP/olive oil interactions and 4 ICs for PLA/olive oil interactions.
Materials and methods
Olive oil /PLA interactions
Olive oil /PP Interactions
Accelerated aging tests
Peaks that appear at λex = 230 nm and λem = 330 nm could be attributed to primary oxidation products (hydroperoxides).
XP-ENV [4]
1 dm ² PP/PLA (reference)
1 dm ² of PP/PLA in 100 ml of olive oil (n=3 replicates)
100 ml olive oil (reference)
CHIMIOMETRIE 2013, September
T = 40˚C for 10, 20, 30 days
Fluorescence on olive oil samples
λex : nm
λem: nm
Integration time : 0.20s
Angle: 47˚
Olive oil /PLA interactions
Olive oil /PP Interactions
Peaks that appear at 304 and 322 nm may be attributed to degradation products of hydroperoxides and other oil components, formed during aging at 40˚C (secondary oxidation products).
Treatment of spectra by chemometric tools
ICA: to recover pure signals.
ICA was applied on two data matrices of 42 spectra * ​​ variables; the first one with spectra of oils in contact with PP and the second one with PLA.
ICA by blocks: to determine the best number of ICs [5].
Data analysis was done using MATLAB-R2011b.
Reference oils aged faster than oils in contact with PP and PLA. A migration of antioxidants, which prevented oil adulteration during aging, may be responsible of this result.
Bibliography
Conclusion
[1] A.I. Méndez, E. Falqué. Effect of storage time and container type on the quality of extra-virgin olive oil, Food Control, 2007; 18: 521–529.
[2] C. Duval. Polypropylène. AM 3 320, 2012, Technique de l’ingénieur.
[3] A.E. Feigenbaum, A.M. Riquet, V. Ducruet, D. Scholler. Safety and quality of foodstuffs in contact with plastic materials : a structural approach. Journal Of Chemical Education, 1993; 70 :
[4] XP ENV Materials and articles in contact with foodstuffs-Plastics. Part 2: Test methods for overall migration into olive oil by total immersion
[5] D. Jouan-Rimbaud Bouveresse; A. Moya-Gonzalez; F. Ammari; D.N. Rutledge. Two novel methods for the determination of the number of components in independent components analysis models. Chemom. Intell. Lab. Syst., 2012; 112:
The developed approach showed a possible migration of antioxidants from PP and PLA packaging which stabilized oil and slowed its oxidation.
The combination between Independent Components Analysis (ICA) and 3D front face fluorescence proved to be very useful to study the interaction between PP and PLA packaging and olive oil.
AgroParisTech, UMR 1145 Ingénierie Procédés Aliments, France ER004, Lebanese Food Packaging, Lebanese University, Lebanon.