Revealing the invisible changes in FTIR spectra upon storage of edible composite films using two dimensional correlation analysis |
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| Matsakidou, A., Tsimidou, M. Z., Kiosseoglou, V. |
- Abstract:
- Attenuated Total Reflectance/Fourrier Transform Infra Red (ATR/FTIR) Spectroscopy is a powerful technique for the rapid extraction of information from complex matrices such as the composite films that are based on edible biopolymers. These films are used for the protection of food products against moisture uptake and are consumed with them. In order to be suitable for food packaging they need to be stable against physical and chemical changes upon storage. FTIR is a convenient tool to examine the film compounds and changes due to their interactions during ageing. However, the incorporation of a hydrophobic compound into the plasticized biopolymer matrix leads to a complex FTIR spectrum due to peak overlapping, which increases uncertainty concerning peak assignment to specific compounds. Moreover, the complexity of the spectrum prevents the identification of small changes during storage. Literature on FTIR data mostly relies on chemometric approaches. In this work, the effectiveness of the Two Dimensional Correlation Analysis (2D-Cor) to increase spectral resolution by analyzing spectrum into two dimensions and hence allows to differentiate overlapping peaks is exemplified. 2D-Cor analysis was carried out in ATR/FTIR spectra of composite oil bodies-sodium caseinate based edible films plasticized by glycerol during storage under mild conditions for 60 days. Invisible, otherwise, physical changes, due to water uptake and glycerol migration to the film surface, and chemical changes, due to lipid hydrolysis, were revealed using this mathematical treatment of spectra. Correlations and sequences of changes at various wavelengths are presented and discussed.
- Keywords:
- FTIR, 2Dimensional Correlation Analysis, edible films, oil bodies, storage
- Download:
- IMEKO-TC23-2017-020.pdf
- DOI:
- -
- Event details
- IMEKO TC:
- TC23
- Event name:
- 3rd IMEKOFOODS Conference
- Title:
Metrology Promoting Standardization and Harmonization in Food and Nutrition
- Place:
- Thessaloniki, GREECE
- Time:
- 01 October 2017 - 04 October 2017