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Gonzalez-Perez J.A.,IRNAS CSIC Av. Reina Mercedes | Jimenez-Morillo N.T.,IRNAS CSIC Av. Reina Mercedes | de la Rosa J.M.,IRNAS CSIC Av. Reina Mercedes | Almendros G.,MNCN CSIC c Serrano 115 B 28006 Madrid Spain | Gonzalez-Vila F.J.,IRNAS CSIC Av. Reina Mercedes
Journal of the Science of Food and Agriculture | Year: 2015

BACKGROUND: Pyrolysis-compound specific isotopic analysis (Py-CSIA: Py-GC-(FID)-C-IRMS) is a relatively novel technique that allows on-line quantification of stable isotope proportions in chromatographically separated products released by pyrolysis. Validation of the Py-CSIA technique is compulsory for molecular traceability in basic and applied research. In this work, commercial sucrose from C4 (sugarcane) and C3 (sugarbeet) photosystem plants and admixtures were studied using analytical pyrolysis (Py-GC/MS), bulk δ13C IRMS and δ13C Py-CSIA. RESULTS: Major pyrolysis compounds were furfural (F), furfural-5-hydroxymethyl (HMF) and levoglucosan (LV). Bulk and main pyrolysis compound δ13C (‰) values were dependent on plant origin: C3 (F, -24.65 ± 0.89; HMF, -22.07 ± 0.41‰; LV, -21.74 ± 0.17‰) and C4 (F, -14.35 ± 0.89‰; HMF, -11.22 ± 0.54‰; LV, -11.44 ± 1.26‰). Significant regressions were obtained for δ13C of bulk and pyrolysis compounds in C3 and C4 admixtures. Furfural (F) was found 13C depleted with respect to bulk and HMF and LV, indicating the incorporation of the light carbon atom in position 6 of carbohydrates in the furan ring after pyrolysis. CONCLUSION: This is the first detailed report on the δ13C signature of major pyrolytically generated carbohydrate-derived molecules. The information provided by Py-CSIA is valuable for identifying source marker compounds of use in food science/fraud detection or in environmental research. © 2015 Society of Chemical Industry.

Llana-Ruiz-Cabello M.,University of Seville | Pichardo S.,University of Seville | Jimenez-Morillo N.T.,IRNAS CSIC Av. Reina Mercedes | Bermudez J.M.,Area of Packaging Materials and Systems ITENE C Albert Einstein 1 46980 Paterna | And 4 more authors.
Journal of the Science of Food and Agriculture | Year: 2015

BACKGROUND: Environmental, economic and safety challenges motivate shift towards safer materials for food packaging. New bioactive packaging techniques, i.e. addition of essential plant oils (EOs), are gaining attention by creating barriers to protect products from spoilage. Analytical pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) was used to fingerprint a bioactive polylactic acid (PLA) with polybutylene succinate (PBS) (950 g kg-1:50 g kg-1) film extruded with variable quantities (0, 20, 50 and 100 g kg-1) of Origanum vulgare EO. RESULTS: Main PLA:PBS pyrolysis products were lactide enantiomers and monomer units from the major PLA fraction and succinic acid anhydride from the PBS fraction. Oregano EO pyrolysis released cymene, terpinene and thymol/carvacrol peaks as diagnostic peaks for EO. In fact, linear correlation coefficients better than 0.950R2 value (P < 0.001) were found between the chromatographic area of the diagnostic peaks and the amount of oregano EO in the bioplastic. CONCLUSION: The pyrolytic behaviour of a bio-based active package polymer including EO is studied in detail. Identified diagnostic compounds provide a tool to monitor the quantity of EO incorporated into the PLA:PBS polymeric matrix. Analytical pyrolysis is proposed as a rapid technique for the identification and quantification of additives within bio-based plastic matrices. © 2015 Society of Chemical Industry.

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