Naslov
Mechanical Degradation of Food Packaging Polymeric Materials

Autori
Klepac, Damir ; Ščetar, Mario ; Valić, Srećko ; Kurek, Mia ; Galić, Kata

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
15th World Congress of Food Science and Technology : Book of Abstracts / Sigge, Gunnar - Cape Town : South African Associateion for Food Science and Technology, 2010, 290-290

Skup
World Congress of Food Science and Technology (15 ; 2010)

Mjesto i datum
Cape Town, Južnoafrička Republika, 22.08.2010. - 26.08.2010

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
mechanical degradation; permeability; polymers

Sažetak
Transport and handling induced damages of packaging materials can strongly influence the quality and the shelf life of food products. Commercially available linear low density polyethylene (LLDPE) and polypropylene (PP) thin films were exposed to uniaxial mechanical deformation which presented the simulation of possible damage provoked by products transport and handling. The deformation was applied in directions parallel and perpendicular to the orientation occurred by films production process. The degree of deformation, defined as lamda=I/Io, I and Io being the sample lengths in preferential direction of the deformed and relaxed state, respectively, was varied from 1.00 (non-deformed state) to 2.50. The effect of deformation was investigated by measuring gas barrier characteristics of the samples before and after application of the mechanical force and attributed to changes in the crystallinity, free volume and molecular dynamics in the amorphous phase. Differences in the degree of crystallinity were measured by DSC, and electron spin resonance (ESR) spectroscopy – spin probe method was used to investigate differences in the motional behavior of chain segments in LLDPE samples underwent mechanical deformation. Oxygen permeability increased by deforming PP in both directions. Contrary, the permeability of LLDPE increased by perpendicular deformation but decreased by parallel deformation. Both materials have shown an increase in the crystallinity for parallel deformation and a decrease for perpendicular deformation. Mechanical deformation leads to material degradation that may cause unwanted effects on quality and the shelf life of food products.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Prehrambena tehnologija

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