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Degradation of low density polyethylene during extrusion. IV. Off‐flavor compounds in extruded films of stabilized LDPE
Author(s) -
Andersson Thorbjörn,
Holmgren Max Hallin,
Nielsen Tim,
Wesslén Bengt
Publication year - 2004
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.21264
Subject(s) - low density polyethylene , extrusion , flavor , polyethylene , materials science , polymer , degradation (telecommunications) , chemical engineering , thermal oxidation , chemistry , organic chemistry , composite material , food science , telecommunications , computer science , engineering , layer (electronics)
This study was aimed at finding a correlation between the experienced off‐flavor in packed foods and the presence of specific degradation products in LDPE packaging films. The possibility to trap degradation products by chemical reactions with scavengers, i.e., a zeolite additive or antioxidants, was investigated This would prevent degradation products from migrating to the polymer film surface and further into food in contact with the film. It was found that off‐flavor noted in water packed in LDPE films depended on extrusion temperature and exposure time for the melt to oxygen, that is, the parameters that influence the contents of oxidation products that are able to migrate from the polymer film. It was also found that adsorption of oxidative degradation products in a zeolite additive or protection of LDPE by using antioxidants could prevent off‐flavor in the packed product (water). However, the antioxidant should be selected with regard to extrusion temperature because thermal instability in the additive might jeopardize the intended effect. Multifunctional antioxidants seem to provide improved protection, the most effective one evaluated in this work being Irganox E201, i.e., vitamin E. Concentrations of oxidized degradation products are well correlated to the perceived off‐flavor in the packed water. The highest correlation between off‐flavor and oxidized components was found for ketones in the range of C 7 to C 9 and aldehydes in the range of C 6 to C 9 . © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 583–595, 2005